1
|
Chen J, Wang Q, He X, Yang B. Malaria Vaccines: Current Achievements and Path Forward. Vaccines (Basel) 2025; 13:542. [PMID: 40432151 PMCID: PMC12115420 DOI: 10.3390/vaccines13050542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2025] [Revised: 04/24/2025] [Accepted: 04/25/2025] [Indexed: 05/29/2025] Open
Abstract
Malaria remains a significant global health challenge. Although the recent approval of the liver-stage vaccines RTS, S and R21 marks significant progress in malaria control, challenges remain in achieving long-lasting and broad protection. In this review, we provide an overview of the current landscape of malaria control, especially anti-malaria vaccine development. We first review the development of the RTS, S and R21 vaccines, highlighting their efficacy and limitations. We then examine other vaccines in development, including attenuated whole-sporozoite vaccines, as well as blood-stage-targeting vaccines and transmission-blocking vaccines targeting a variety of different immunogens. Additionally, we discuss emerging technologies, such as mRNA-based platforms, nanoparticle delivery systems, and novel adjuvants, assessing their potential to enhance the efficacy and mitigate the waning immunity concerns of most malaria vaccines. We believe that the identification of novel immunogen candidates, together with continued innovation in vaccine design and delivery, will enable us to win the fight against malaria in the future.
Collapse
Affiliation(s)
- Jiayan Chen
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.C.); (Q.W.); (X.H.)
| | - Qi Wang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.C.); (Q.W.); (X.H.)
| | - Xiaomeng He
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.C.); (Q.W.); (X.H.)
| | - Bei Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; (J.C.); (Q.W.); (X.H.)
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
- Shanghai Frontiers Science Center for Biomacromolecules and Precision Medicine, ShanghaiTech University, Shanghai 200031, China
| |
Collapse
|
2
|
Patel PN, Diouf A, Dickey TH, Tang WK, Hopp CS, Traore B, Long CA, Miura K, Crompton PD, Tolia NH. A strain-transcending anti-AMA1 human monoclonal antibody neutralizes malaria parasites independent of direct RON2L receptor blockade. Cell Rep Med 2025; 6:101985. [PMID: 40020675 PMCID: PMC11970402 DOI: 10.1016/j.xcrm.2025.101985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2024] [Revised: 01/06/2025] [Accepted: 01/31/2025] [Indexed: 03/03/2025]
Abstract
Plasmodium falciparum apical membrane antigen 1 (AMA1) binds a loop in rhoptry neck protein 2 (RON2L) during red cell invasion and is a target for vaccines and therapeutic antibodies against malaria. Here, we report a panel of AMA1-specific naturally acquired human monoclonal antibodies (hmAbs) derived from individuals living in malaria-endemic regions. Two neutralizing hmAbs engage AMA1 independent of the RON2L-binding site. The hmAb 75B10 demonstrates potent strain-transcending neutralization that is independent of RON2L blockade, emphasizing that epitopes outside the RON2L-binding site elicit broad protection against variant parasite strains. The combination of these hmAbs synergistically enhances parasite neutralization. Vaccination with a structure-based design (SBD1) that mimics the AMA1-RON2L complex elicited antibodies similar to the two neutralizing hmAbs connecting vaccination to naturally acquired immunity in humans. The structural definition of a strain-transcending epitope on AMA1 targeted by naturally acquired hmAb establishes paradigms for developing AMA1-based vaccines and therapeutic antibodies.
Collapse
Affiliation(s)
- Palak N Patel
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Wai Kwan Tang
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Christine S Hopp
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Boubacar Traore
- Malaria Research and Training Centre, Mali International Center of Excellence in Research, University of Sciences, Techniques and Technologies of Bamako, Point G, Bamako 1805, Mali
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
3
|
Kegawa Y, Male F, Jiménez-Munguía I, Blank PS, Mekhedov E, Ward G, Zimmerberg J. The invasion pore induced by Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.11.617945. [PMID: 39416144 PMCID: PMC11482919 DOI: 10.1101/2024.10.11.617945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
Obligate intracellular parasites invade host cells to survive. Following host cell contact, the apicomplexan Toxoplasma gondii injects proteins required for invasion into the host cell. Here, electrophysiological recordings of host cells acquired at sub-200 ms resolution allowed detection and analysis of a transient increase in host membrane conductance following exposure to Toxoplasma gondii. Transients always preceded invasion but parasites depleted of the moving junction protein RON2 generated transients without invading, ruling out a direct structural role for RON2 in generating the conductance pathway or restricting the diffusion of its components. Time-series analysis developed for transients and applied to the entire transient dataset (910,000 data points) revealed multiple quantal conductance changes in the parasite-induced transient, consistent with a rapid insertion, then slower removal, blocking, or inactivation of pore-like conductance steps. Quantal steps for RH had a principal mode with Gaussian mean of 0.26 nS, similar in step size to the apicomplexan protein translocon EXP2. Without RON2 the quantal mean was significantly different (0.19 nS). Because no invasion occurs without poration, the term 'invasion pore' is proposed.
Collapse
Affiliation(s)
- Y Kegawa
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - F Male
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, United States
| | - I Jiménez-Munguía
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - P S Blank
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - E Mekhedov
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - G Ward
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, United States
| | - J Zimmerberg
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| |
Collapse
|
4
|
Male F, Kegawa Y, Blank PS, Jiménez-Munguía I, Sidik SM, Valleau D, Lourido S, Lebrun M, Zimmerberg J, Ward GE. Perforation of the host cell plasma membrane during Toxoplasma gondii invasion requires rhoptry exocytosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.12.618018. [PMID: 39605356 PMCID: PMC11601479 DOI: 10.1101/2024.10.12.618018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2024]
Abstract
Toxoplasma gondii is an obligate intracellular parasite, and the delivery of effector proteins from the parasite into the host cell during invasion is critical for invasion itself and for parasite virulence. The effector proteins are released from specialized apical secretory organelles known as rhoptries. While much has been learned recently about the structure and composition of the rhoptry exocytic machinery and the function of individual rhoptry effector proteins that are exocytosed, virtually nothing is known about how the released proteins are translocated across the host cell plasma membrane. Previous electrophysiology experiments reported an unanticipated observation that invasion by T. gondii is preceded by a transient increase in host cell plasma membrane conductance. Here, we confirm this electrophysiological observation and propose that the conductance transient represents a parasite-induced perforation in the host cell plasma membrane through which rhoptry proteins are delivered. As a first step towards testing this hypothesis, and to provide higher throughput than patch clamp electrophysiology, we developed an alternative assay to detect the perforation. This assay utilizes high-speed, multi-wavelength fluorescence imaging to enable simultaneous visualization of host cell perforation and parasite invasion. Using this assay, we interrogated a panel of mutant parasites conditionally depleted of key invasion-related proteins. Parasites lacking signaling proteins involved in triggering rhoptry secretion (e.g., CLAMP) or components of the rhoptry exocytic machinery (e.g., Nd9, RASP2) are defective in their ability to induce the perforation. These data are consistent with a model in which the perforating agents that disrupt host cell membrane integrity during invasion - and may thereby provide the conduit for delivery of rhoptry effector proteins - are stored within the rhoptries themselves and released upon contact with the host cell.
Collapse
Affiliation(s)
- Frances Male
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - Yuto Kegawa
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Paul S Blank
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Irene Jiménez-Munguía
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | | | | | - Sebastian Lourido
- Whitehead Institute, Cambridge, Massachusetts, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Maryse Lebrun
- LPHI, CNRS, INSERM, Université de Montpellier, 34095 Montpellier, France
| | - Joshua Zimmerberg
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Gary E Ward
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| |
Collapse
|
5
|
Weng S, Tian E, Gao M, Zhang S, Yang G, Zhou B. Eimeria: Navigating complex intestinal ecosystems. PLoS Pathog 2024; 20:e1012689. [PMID: 39576763 PMCID: PMC11584145 DOI: 10.1371/journal.ppat.1012689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2024] Open
Abstract
Eimeria is an intracellular obligate apicomplexan parasite that parasitizes the intestinal epithelial cells of livestock and poultry, exhibiting strong host and tissue tropism. Parasite-host interactions involve complex networks and vary as the parasites develop in the host. However, understanding the underlying mechanisms remains a challenge. Acknowledging the lack of studies on Eimeria invasion mechanism, we described the possible invasion process through comparative analysis with other apicomplexan parasites and explored the fact that parasite-host interactions serve as a prerequisite for successful recognition, penetration of the intestinal mechanical barrier, and completion of the invasion. Although it is recognized that microbiota can enhance the host immune capacity to resist Eimeria invasion, changes in the microenvironment can, in turn, contribute to Eimeria invasion and may be associated with reduced immune capacity. We also discuss the immune evasion strategies of Eimeria, emphasizing that the host employs sophisticated immune regulatory mechanisms to suppress immune evasion by parasites, thereby sustaining a balanced immune response. This review aims to deepen our understanding of Eimeria-host interactions, providing a theoretical basis for the study of the pathogenicity of Eimeria and the development of novel anticoccidial drugs.
Collapse
Affiliation(s)
- Shengjie Weng
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| | - Erjie Tian
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| | - Meng Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| | - Siyu Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| | - Guodong Yang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| | - Bianhua Zhou
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China
| |
Collapse
|
6
|
Wang C, Sun P, Jia Y, Tang X, Liu X, Suo X, Peng H. Protein disulfide isomerase PDI8 is indispensable for parasite growth and associated with secretory protein processing in Toxoplasma gondii. mBio 2024; 15:e0205124. [PMID: 39162526 PMCID: PMC11389393 DOI: 10.1128/mbio.02051-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Accepted: 07/12/2024] [Indexed: 08/21/2024] Open
Abstract
Protein disulfide isomerase, containing thioredoxin (Trx) domains, serves as a vital enzyme responsible for oxidative protein folding (the formation, reduction, and isomerization of disulfide bonds in newly synthesized proteins) in the endoplasmic reticulum (ER). However, the role of ER-localized PDI proteins in parasite growth and their interaction with secretory proteins remain poorly understood. In this study, we identified two ER-localized PDI proteins, TgPDI8 and TgPDI6, in Toxoplasma gondii. Conditional knockdown of TgPDI8 resulted in a significant reduction in intracellular proliferation and invasion abilities, leading to a complete block in plaque formation on human foreskin fibroblast monolayers, whereas parasites lacking TgPDI6 did not exhibit any apparent fitness defects. The complementation of TgPDI8 with mutant variants highlighted the critical role of the CXXC active site cysteines within its Trx domains for its enzymatic activity. By utilizing TurboID-based proximity labeling, we uncovered a close association between PDI proteins and canonical secretory proteins. Furthermore, parasites lacking TgPDI8 showed a significant reduction in the expression of secretory proteins, especially those from micronemes and dense granules. In summary, our study elucidates the roles of TgPDI8 and sets the stage for future drug discovery studies. IMPORTANCE Apicomplexans, a phylum of intracellular parasites, encompass various zoonotic pathogens, including Plasmodium, Cryptosporidium, Toxoplasma, and Babesia, causing a significant economic burden on human populations. These parasites exhibit hypersensitivity to disruptions in endoplasmic reticulum (ER) redox homeostasis, necessitating the presence of ER-localized thioredoxin (Trx) superfamily proteins, particularly protein disulfide isomerase (PDI), for proper oxidative folding. However, the functional characteristics of ER-localized PDI proteins in Toxoplasma gondii remain largely unexplored. In this study, we identified two ER-localized proteins, namely, TgPDI8 and TgPDI6, and demonstrated the indispensable role of TgPDI8 in parasite survival. Through a comprehensive multi-omics analysis, we elucidated the crucial role of TgPDI8 in the processing of secretory proteins in T. gondii. Additionally, we introduced a novel ER-anchored TurboID method to label and identify canonical secretory proteins in T. gondii. This research opens up new avenues for understanding oxidative folding and the secretory pathway in apicomplexan parasites, laying the groundwork for future advancements in antiparasitic drug development.
Collapse
Affiliation(s)
- Chaoyue Wang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Diseases Research, School of Public Health, Southern Medical University, Guangzhou City, Guangdong Province, China
- Key Laboratory of Infectious Diseases Research in South China (Ministry of Education), Southern Medical University, Guangzhou, Guangdong, China
| | - Pei Sun
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou, Guangdong Province, China
| | - Yonggen Jia
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xinming Tang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xianyong Liu
- National Key Laboratory of Veterinary Public Health Security, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xun Suo
- National Key Laboratory of Veterinary Public Health Security, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Diseases Research, School of Public Health, Southern Medical University, Guangzhou City, Guangdong Province, China
- Key Laboratory of Infectious Diseases Research in South China (Ministry of Education), Southern Medical University, Guangzhou, Guangdong, China
| |
Collapse
|
7
|
Tang L, Sabi MM, Fu M, Guan J, Wang Y, Xia T, Zheng K, Qu H, Han B. Host cell manipulation by microsporidia secreted effectors: Insights into intracellular pathogenesis. J Eukaryot Microbiol 2024; 71:e13029. [PMID: 39030770 DOI: 10.1111/jeu.13029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 07/22/2024]
Abstract
Microsporidia are prolific producers of effector molecules, encompassing both proteins and nonproteinaceous effectors, such as toxins, small RNAs, and small peptides. These secreted effectors play a pivotal role in the pathogenicity of microsporidia, enabling them to subvert the host's innate immunity and co-opt metabolic pathways to fuel their own growth and proliferation. However, the genomes of microsporidia, despite falling within the size range of bacteria, exhibit significant reductions in both structural and physiological features, thereby affecting the repertoire of secretory effectors to varying extents. This review focuses on recent advances in understanding how microsporidia modulate host cells through the secretion of effectors, highlighting current challenges and proposed solutions in deciphering the complexities of microsporidial secretory effectors.
Collapse
Affiliation(s)
- Liyuan Tang
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Musa Makongoro Sabi
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Ming Fu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Jingyu Guan
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Yongliang Wang
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Tian Xia
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Kai Zheng
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
| | - Hongnan Qu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
- Shenzhen Research Institute, Shandong University, Shenzhen, Guangdong, China
| | - Bing Han
- Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong, China
- Shenzhen Research Institute, Shandong University, Shenzhen, Guangdong, China
| |
Collapse
|
8
|
Li F, Guo J, Wang S, Han Z, Nie Z, Yu L, Shu X, Xia Y, He L, Zhao J. Identification and molecular characterization of a novel Babesia orientalis rhoptry neck protein 4 (BoRON4). Parasitol Res 2024; 123:310. [PMID: 39207503 DOI: 10.1007/s00436-024-08328-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024]
Abstract
Babesia orientalis, a protozoan parasite transmitted by the tick Rhipicephalus haemaphysaloides, holds significant economic importance along the Yangtze River. Key factors in the host invasion process include rhoptry neck proteins (RON2, RON4, and RON5) and apical membrane antigen 1 (AMA1). However, the intricacies of the interaction between AMA1 and RONs remain incompletely elucidated in B. orientalis. To better understand these crucial invasion components, the RON4 gene of B. orientalis (BoRON4) was cloned and sequenced. RON4 is 3468 base pairs long, encodes 1155 amino acids, and has a predicted molecular weight of 130 kDa. Bioinformatics analysis revealed a unique region (amino acid residues 109-452) in BoRON4, which demonstrates higher sensitivity to epitope activity. The BoRON4 gene was strategically truncated, amplified, and cloned into the pGEX-6p-1 vector for fusion expression. We successfully used the mouse polyclonal antibody to identify native BoRON4 in B. orientalis lysates. Furthermore, the corresponding BoRON4 protein band was detected in the water buffalo serum infected with B. orientalis, while no such band was observed in the control. Additionally, I-TASSER and Discovery Studio software were used to predict the tertiary structures of BoRON4 and its ligands, CH-PKA and CH-complex. These ligands can serve as lead compounds for the development of anti-babesiosis drugs. In conclusion, BoRON4 emerges as a promising candidate antigen for distinguishing water buffalo infected with B. orientalis from their normal counterparts. This study positions BoRON4 as a potential diagnostic antigen for babesiosis in water buffalo, contributing valuable insights to the field of parasitology.
Collapse
Affiliation(s)
- Fangjie Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Jiaying Guo
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Sen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Zhen Han
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Zheng Nie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Long Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Xiang Shu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Yingjun Xia
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, 430070, Hubei, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, Hubei, China.
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, 430070, Hubei, China.
| |
Collapse
|
9
|
Angage D, Chmielewski J, Maddumage JC, Hesping E, Caiazzo S, Lai KH, Yeoh LM, Menassa J, Opi DH, Cairns C, Puthalakath H, Beeson JG, Kvansakul M, Boddey JA, Wilson DW, Anders RF, Foley M. A broadly cross-reactive i-body to AMA1 potently inhibits blood and liver stages of Plasmodium parasites. Nat Commun 2024; 15:7206. [PMID: 39174515 PMCID: PMC11341838 DOI: 10.1038/s41467-024-50770-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 07/19/2024] [Indexed: 08/24/2024] Open
Abstract
Apical membrane antigen-1 (AMA1) is a conserved malarial vaccine candidate essential for the formation of tight junctions with the rhoptry neck protein (RON) complex, enabling Plasmodium parasites to invade human erythrocytes, hepatocytes, and mosquito salivary glands. Despite its critical role, extensive surface polymorphisms in AMA1 have led to strain-specific protection, limiting the success of AMA1-based interventions beyond initial clinical trials. Here, we identify an i-body, a humanised single-domain antibody-like molecule that recognises a conserved pan-species conformational epitope in AMA1 with low nanomolar affinity and inhibits the binding of the RON2 ligand to AMA1. Structural characterisation indicates that the WD34 i-body epitope spans the centre of the conserved hydrophobic cleft in AMA1, where interacting residues are highly conserved among all Plasmodium species. Furthermore, we show that WD34 inhibits merozoite invasion of erythrocytes by multiple Plasmodium species and hepatocyte invasion by P. falciparum sporozoites. Despite a short half-life in mouse serum, we demonstrate that WD34 transiently suppressed P. berghei infections in female BALB/c mice. Our work describes the first pan-species AMA1 biologic with inhibitory activity against multiple life-cycle stages of Plasmodium. With improved pharmacokinetic characteristics, WD34 could be a potential immunotherapy against multiple species of Plasmodium.
Collapse
Affiliation(s)
- Dimuthu Angage
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - Jill Chmielewski
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Janesha C Maddumage
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - Eva Hesping
- Infectious Diseases & Immune Defense Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Sabrina Caiazzo
- Infectious Diseases & Immune Defense Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Keng Heng Lai
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Lee Ming Yeoh
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Joseph Menassa
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - D Herbert Opi
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, 3052, Australia
- Central Clinical School and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Callum Cairns
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - Hamsa Puthalakath
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Central Clinical School and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
- Department of Infectious Diseases, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Marc Kvansakul
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - Justin A Boddey
- Infectious Diseases & Immune Defense Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Robin F Anders
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia
| | - Michael Foley
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, 3086, Australia.
- AdAlta, Science Drive, Bundoora, Victoria, 3083, Australia.
| |
Collapse
|
10
|
Dangoudoubiyam S, Norris JK, Namasivayam S, de Paula Baptista R, Cannes do Nascimento N, Camp J, Schardl CL, Kissinger JC, Howe DK. Temporal gene expression during asexual development of the apicomplexan Sarcocystis neurona. mSphere 2024; 9:e0011124. [PMID: 38809064 PMCID: PMC11332336 DOI: 10.1128/msphere.00111-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/23/2024] [Indexed: 05/30/2024] Open
Abstract
Asexual replication in the apicomplexan Sarcocystis neurona involves two main developmental stages: the motile extracellular merozoite and the sessile intracellular schizont. Merozoites invade host cells and transform into schizonts that undergo replication via endopolygeny to form multiple (64) daughter merozoites that are invasive to new host cells. Given that the capabilities of the merozoite vary significantly from the schizont, the patterns of transcript levels throughout the asexual lifecycle were determined and compared in this study. RNA-Seq data were generated from extracellular merozoites and four intracellular schizont development time points. Of the 6,938 genes annotated in the S. neurona genome, 6,784 were identified in the transcriptome. Of these, 4,111 genes exhibited significant differential expression between the merozoite and at least one schizont development time point. Transcript levels were significantly higher for 2,338 genes in the merozoite and 1,773 genes in the schizont stages. Included in this list were genes encoding the secretory pathogenesis determinants (SPDs), which encompass the surface antigen and SAG-related sequence (SAG/SRS) and the secretory organelle proteins of the invasive zoite stage (micronemes, rhoptries, and dense granules). As anticipated, many of the S. neurona SPD gene transcripts were abundant in merozoites. However, several SPD transcripts were elevated in intracellular schizonts, suggesting roles unrelated to host cell invasion and the initial establishment of the intracellular niche. The hypothetical genes that are potentially unique to the genus Sarcocystis are of particular interest. Their conserved expression patterns are instructive for future investigations into the possible functions of these putative Sarcocystis-unique genes. IMPORTANCE The genus Sarcocystis is an expansive clade within the Apicomplexa, with the species S. neurona being an important cause of neurological disease in horses. Research to decipher the biology of S. neurona and its host-pathogen interactions can be enhanced by gene expression data. This study has identified conserved apicomplexan orthologs in S. neurona, putative Sarcocystis-unique genes, and gene transcripts abundant in the merozoite and schizont stages. Importantly, we have identified distinct clusters of genes with transcript levels peaking during different intracellular schizont development time points, reflecting active gene expression changes across endopolygeny. Each cluster also has subsets of transcripts with unknown functions, and investigation of these seemingly Sarcocystis-unique transcripts will provide insights into the interesting biology of this parasite genus.
Collapse
Affiliation(s)
- Sriveny Dangoudoubiyam
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA
| | - Jamie K. Norris
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA
| | - Sivaranjani Namasivayam
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Genetics, University of Georgia, Athens, Georgia, USA
| | - Rodrigo de Paula Baptista
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, USA
| | - Naila Cannes do Nascimento
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - Joseph Camp
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | | | - Jessica C. Kissinger
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Genetics, University of Georgia, Athens, Georgia, USA
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, USA
| | - Daniel K. Howe
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA
| |
Collapse
|
11
|
Cuy-Chaparro L, Barney-Borrero D, Arévalo-Pinzón G, Reyes C, Moreno-Pérez DA, Patarroyo MA. Babesia bovis RON2 binds to bovine erythrocytes through a highly conserved epitope. Vet Parasitol 2024; 326:110081. [PMID: 38113611 DOI: 10.1016/j.vetpar.2023.110081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/25/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023]
Abstract
B. bovis invasion of bovine erythrocytes requires tight junction formation involving AMA-1/RON2 complex interaction. RON2 has been considered a vaccine candidate since antibodies targeting the protein can inhibit parasite invasion of target cells; however, the mechanism controlling B. bovis RON2 interaction with red blood cells is not yet fully understood. This study was thus aimed at identifying B. bovis RON2 protein regions associated with interaction with bovine erythrocytes. Natural selection analysis of the ron2 gene identified predominantly negative selection signals in the C-terminal region. Interestingly, protein-cell and competition assays highlighted the RON2-C region's role in peptide 42918-mediated erythrocyte binding, probably to a sialoglycoprotein receptor. This peptide (1218SFIMVKPPALHCVLKPVETL1237) lies within an intrinsically disordered region of the RON2 secondary structure flanked by two helical residues. The study provides, for the first time, valuable insights into RON2's role in interaction with its target cells. Future studies are required for studying the peptide's potential as an anti-B. bovis vaccine component.
Collapse
Affiliation(s)
- Laura Cuy-Chaparro
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia [FIDIC], Carrera 50#26-20, Bogotá DC 111321, Colombia; PhD Programme in Biotechnology, Universidad Nacional de Colombia, Carrera 45#26-85, Bogotá DC 111321, Colombia.
| | - Danny Barney-Borrero
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia [FIDIC], Carrera 50#26-20, Bogotá DC 111321, Colombia.
| | - Gabriela Arévalo-Pinzón
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia [FIDIC], Carrera 50#26-20, Bogotá DC 111321, Colombia.
| | - César Reyes
- Structure Analysis Department, Fundación Instituto de Inmunología de Colombia [FIDIC], Carrera 50#26-20, Bogotá DC 111321, Colombia.
| | - Darwin Andrés Moreno-Pérez
- Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales [U.D.C.A.], Calle 222#55-37, Bogotá DC 111166, Colombia.
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia [FIDIC], Carrera 50#26-20, Bogotá DC 111321, Colombia; Microbiology Department, Faculty of Medicine, Universidad Nacional de Colombia, Carrera 45#26-85, Bogotá DC 111321, Colombia.
| |
Collapse
|
12
|
Sitaraman R. Subversion from Within and Without: Effector Molecule Transfer from Obligate Intracellular Apicomplexan Parasites to Human Host Cells. Results Probl Cell Differ 2024; 73:521-535. [PMID: 39242391 DOI: 10.1007/978-3-031-62036-2_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2024]
Abstract
Intracellular protozoan pathogens have to negotiate the internal environment of the host cell they find themselves in, as well as manipulate the host cell to ensure their own survival, replication, and dissemination. The transfer of key effector molecules from the pathogen to the host cell is crucial to this interaction and is technically more demanding to study as compared to an extracellular pathogen. While several effector molecules have been identified, the mechanisms and conditions underlying their transfer to the host cell remain partly or entirely unknown. Improvements in experimental systems have revealed tantalizing details of such intercellular transfer, which form the subject of this chapter.
Collapse
|
13
|
de Souza Teles ER, de Araujo Portes J, de Souza W. New morphological observations on the initial events of Toxoplasma gondii entry into host cells. Vet Parasitol 2023; 322:110006. [PMID: 37633244 DOI: 10.1016/j.vetpar.2023.110006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/05/2023] [Accepted: 08/09/2023] [Indexed: 08/28/2023]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan of worldwide distribution. It is effective in the infection of various homoeothermic animals of economic importance. The process of T. gondii invasion of host cells occurs in less than 20 s by the active mechanism of penetration. First, a mobile junction is formed due to the association between the apical end of the parasite and the host cell surface. Then, the secretion of invasive and docking proteins allows the formation of the mobile junction before the complete internalization of the parasite. Here, using high-resolution microscopy, it was described new morphological observations of the early events of host cell invasion by tachyzoites of T. gondii. Attempts were made to synchronize the interaction process using low temperatures and treatment of the host cells with cytochalasin D, a drug that interferes with the actin dynamics. Images were obtained showing that the parasite and the host cells seem to release small vesicles with diameters varying from 25 to 100 nm. Furthermore, tunneling nanotubes emerge from the host cell surface and interact with the parasite even at long distance. These observations add new details of adhesion and entry events, such as surface projections of the host cell plasma membrane, pseudopods, and nanotubes radiating from the host cell toward the parasite. In addition, scanning microscopy revealed intense vesiculation, with a morphological characteristic of extracellular microvesicles, during the entry of the tachyzoite into the host cell.
Collapse
Affiliation(s)
- Everson Reili de Souza Teles
- Laboratório de Ultraestrutura Celular Hertha Meyer, Centro de Pesquisa em Medicina de Precisão, Instituto de Biofísica Carlos Chagas Filho/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana de Araujo Portes
- Laboratório de Ultraestrutura Celular Hertha Meyer, Centro de Pesquisa em Medicina de Precisão, Instituto de Biofísica Carlos Chagas Filho/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Centro de Pesquisa em Medicina de Precisão, Instituto de Biofísica Carlos Chagas Filho/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem - INBEB, and Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Centro de Estudos Biomédicos-CMABio, Escola Superior de Saúde, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil.
| |
Collapse
|
14
|
Patel PN, Dickey TH, Diouf A, Salinas ND, McAleese H, Ouahes T, Long CA, Miura K, Lambert LE, Tolia NH. Structure-based design of a strain transcending AMA1-RON2L malaria vaccine. Nat Commun 2023; 14:5345. [PMID: 37660103 PMCID: PMC10475129 DOI: 10.1038/s41467-023-40878-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/14/2023] [Indexed: 09/04/2023] Open
Abstract
Apical membrane antigen 1 (AMA1) is a key malaria vaccine candidate and target of neutralizing antibodies. AMA1 binds to a loop in rhoptry neck protein 2 (RON2L) to form the moving junction during parasite invasion of host cells, and this complex is conserved among apicomplexan parasites. AMA1-RON2L complex immunization achieves higher growth inhibitory activity than AMA1 alone and protects mice against Plasmodium yoelii challenge. Here, three single-component AMA1-RON2L immunogens were designed that retain the structure of the two-component AMA1-RON2L complex: one structure-based design (SBD1) and two insertion fusions. All immunogens elicited high antibody titers with potent growth inhibitory activity, yet these antibodies did not block RON2L binding to AMA1. The SBD1 immunogen induced significantly more potent strain-transcending neutralizing antibody responses against diverse strains of Plasmodium falciparum than AMA1 or AMA1-RON2L complex vaccination. This indicates that SBD1 directs neutralizing antibody responses to strain-transcending epitopes in AMA1 that are independent of RON2L binding. This work underscores the importance of neutralization mechanisms that are distinct from RON2 blockade. The stable single-component SBD1 immunogen elicits potent strain-transcending protection that may drive the development of next-generation vaccines for improved malaria and apicomplexan parasite control.
Collapse
Affiliation(s)
- Palak N Patel
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Nichole D Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Holly McAleese
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Lynn E Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
15
|
Weiss GE, Ragotte RJ, Quinkert D, Lias AM, Dans MG, Boulet C, Looker O, Ventura OD, Williams BG, Crabb BS, Draper SJ, Gilson PR. The dual action of human antibodies specific to Plasmodium falciparum PfRH5 and PfCyRPA: Blocking invasion and inactivating extracellular merozoites. PLoS Pathog 2023; 19:e1011182. [PMID: 37713419 PMCID: PMC10529537 DOI: 10.1371/journal.ppat.1011182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 09/27/2023] [Accepted: 08/29/2023] [Indexed: 09/17/2023] Open
Abstract
The Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is the current leading blood-stage malaria vaccine candidate. PfRH5 functions as part of the pentameric PCRCR complex containing PTRAMP, CSS, PfCyRPA and PfRIPR, all of which are essential for infection of human red blood cells (RBCs). To trigger RBC invasion, PfRH5 engages with RBC protein basigin in a step termed the RH5-basigin binding stage. Although we know increasingly more about how antibodies specific for PfRH5 can block invasion, much less is known about how antibodies recognizing other members of the PCRCR complex can inhibit invasion. To address this, we performed live cell imaging using monoclonal antibodies (mAbs) which bind PfRH5 and PfCyRPA. We measured the degree and timing of the invasion inhibition, the stage at which it occurred, as well as subsequent events. We show that parasite invasion is blocked by individual mAbs, and the degree of inhibition is enhanced when combining a mAb specific for PfRH5 with one binding PfCyRPA. In addition to directly establishing the invasion-blocking capacity of the mAbs, we identified a secondary action of certain mAbs on extracellular parasites that had not yet invaded where the mAbs appeared to inactivate the parasites by triggering a developmental pathway normally only seen after successful invasion. These findings suggest that epitopes within the PfCyRPA-PfRH5 sub-complex that elicit these dual responses may be more effective immunogens than neighboring epitopes by both blocking parasites from invading and rapidly inactivating extracellular parasites. These two protective mechanisms, prevention of invasion and inactivation of uninvaded parasites, resulting from antibody to a single epitope indicate a possible route to the development of more effective vaccines.
Collapse
Affiliation(s)
- Greta E. Weiss
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Robert J. Ragotte
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
| | - Doris Quinkert
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
| | - Amelia M. Lias
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
| | - Madeline G. Dans
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Coralie Boulet
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Oliver Looker
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Olivia D. Ventura
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Barnabas G. Williams
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
| | - Brendan S. Crabb
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
- The University of Melbourne, Grattan Street, Parkville, Victoria, Australia
| | - Simon J. Draper
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, Oxford, United Kingdom
| | - Paul R. Gilson
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, Australia
- The University of Melbourne, Grattan Street, Parkville, Victoria, Australia
| |
Collapse
|
16
|
Ferrel A, Romano J, Panas MW, Coppens I, Boothroyd JC. Host MOSPD2 enrichment at the parasitophorous vacuole membrane varies between Toxoplasma strains and involves complex interactions. mSphere 2023; 8:e0067022. [PMID: 37341482 PMCID: PMC10449529 DOI: 10.1128/msphere.00670-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
Toxoplasma gondii is an obligate, intracellular parasite. Infection of a cell produces a unique niche for the parasite named the parasitophorous vacuole (PV) initially composed of host plasma membrane invaginated during invasion. The PV and its membrane (parasitophorous vacuole membrane [PVM]) are subsequently decorated with a variety of parasite proteins allowing the parasite to optimally grow in addition to manipulate host processes. Recently, we reported a proximity-labeling screen at the PVM-host interface and identified host endoplasmic reticulum (ER)-resident motile sperm domain-containing protein 2 (MOSPD2) as being enriched at this location. Here we extend these findings in several important respects. First, we show that the extent and pattern of host MOSPD2 association with the PVM differ dramatically in cells infected with different strains of Toxoplasma. Second, in cells infected with Type I RH strain, the MOSPD2 staining is mutually exclusive with regions of the PVM that associate with mitochondria. Third, immunoprecipitation and liquid chromatography tandem mass spectrometry (LC-MS/MS) with epitope-tagged MOSPD2-expressing host cells reveal strong enrichment of several PVM-localized parasite proteins, although none appear to play an essential role in MOSPD2 association. Fourth, most MOSPD2 associating with the PVM is newly translated after infection of the cell and requires the major functional domains of MOSPD2, identified as the CRAL/TRIO domain and tail anchor, although these domains were not sufficient for PVM association. Lastly, ablation of MOSPD2 results in, at most, a modest impact on Toxoplasma growth in vitro. Collectively, these studies provide new insight into the molecular interactions involving MOSPD2 at the dynamic interface between the PVM and the host cytosol. IMPORTANCE Toxoplasma gondii is an intracellular pathogen that lives within a membranous vacuole inside of its host cell. This vacuole is decorated by a variety of parasite proteins that allow it to defend against host attack, acquire nutrients, and interact with the host cell. Recent work identified and validated host proteins enriched at this host-pathogen interface. Here, we follow up on one candidate named MOSPD2 shown to be enriched at the vacuolar membrane and describe it as having a dynamic interaction at this location depending on a variety of factors. Some of these include the presence of host mitochondria, intrinsic domains of the host protein, and whether translation is active. Importantly, we show that MOSPD2 enrichment at the vacuole membrane differs between strains indicating active involvement of the parasite with this phenotype. Altogether, these results shed light on the mechanism and role of protein associations in the host-pathogen interaction.
Collapse
Affiliation(s)
- Abel Ferrel
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, California, USA
| | - Julia Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Michael W. Panas
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, California, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, California, USA
| |
Collapse
|
17
|
Baba M, Nozaki M, Tachibana M, Tsuboi T, Torii M, Ishino T. Rhoptry neck protein 4 plays important roles during Plasmodium sporozoite infection of the mammalian liver. mSphere 2023; 8:e0058722. [PMID: 37272704 PMCID: PMC10449513 DOI: 10.1128/msphere.00587-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 04/05/2023] [Indexed: 06/06/2023] Open
Abstract
During invasion, Plasmodium parasites secrete proteins from rhoptry and microneme apical end organelles, which have crucial roles in attaching to and invading target cells. A sporozoite stage-specific gene silencing system revealed that rhoptry neck protein 2 (RON2), RON4, and RON5 are important for sporozoite invasion of mosquito salivary glands. Here, we further investigated the roles of RON4 during sporozoite infection of the liver in vivo. Following intravenous inoculation of RON4-knockdown sporozoites into mice, we demonstrated that sporozoite RON4 has multiple functions during sporozoite traversal of sinusoidal cells and infection of hepatocytes. In vitro infection experiments using a hepatoma cell line revealed that secreted RON4 is involved in sporozoite adhesion to hepatocytes and has an important role in the early steps of hepatocyte infection. In addition, in vitro motility assays indicated that RON4 is required for sporozoite attachment to the substrate and the onset of migration. These findings indicate that RON4 is crucial for sporozoite migration toward and invasion of hepatocytes via attachment ability and motility.IMPORTANCEMalarial parasite transmission to mammals is established when sporozoites are inoculated by mosquitoes and migrate through the bloodstream to infect hepatocytes. Many aspects of the molecular mechanisms underpinning migration and cellular invasion remain largely unelucidated. By applying a sporozoite stage-specific gene silencing system in the rodent malarial parasite, Plasmodium berghei, we demonstrated that rhoptry neck protein 4 (RON4) is crucial for sporozoite infection of the liver in vivo. Combined with in vitro investigations, it was revealed that RON4 functions during a crossing of the sinusoidal cell layer and invading hepatocytes, at an early stage of liver infection, by mediating the sporozoite capacity for adhesion and the onset of motility. Since RON4 is also expressed in Plasmodium merozoites and Toxoplasma tachyzoites, our findings contribute to understanding the conserved invasion mechanisms of Apicomplexa parasites.
Collapse
Affiliation(s)
- Minami Baba
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Mamoru Nozaki
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Tomoko Ishino
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
- Department of Parasitology and Tropical Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Yushima, Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
18
|
Koutsogiannis Z, Mina JGM, Suman R, Denny PW. Assessment of Toxoplasma gondii lytic cycle and the impact of a gene deletion using 3D label-free optical diffraction holotomography. Front Cell Infect Microbiol 2023; 13:1237594. [PMID: 37600951 PMCID: PMC10433743 DOI: 10.3389/fcimb.2023.1237594] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Toxoplasma gondii is a widespread single-celled intracellular eukaryotic apicomplexan protozoan parasite primarily associated with mammalian foetal impairment and miscarriage, including in humans. Is estimated that approximately one third of the human population worldwide is infected by this parasite. Here we used cutting-edge, label-free 3D quantitative optical diffraction holotomography to capture and evaluate the Toxoplasma lytic cycle (invasion, proliferation and egress) in real-time based on the refractive index distribution. In addition, we used this technology to analyse an engineered CRISPR-Cas9 Toxoplasma mutant to reveal differences in cellular physical properties when compared to the parental line. Collectively, these data support the use of holotomography as a powerful tool for the study of protozoan parasites and their interactions with their host cells.
Collapse
Affiliation(s)
- Zisis Koutsogiannis
- Department of Biosciences, Lower Mountjoy, University of Durham, Durham, United Kingdom
| | - John G. M. Mina
- Department of Biosciences, Lower Mountjoy, University of Durham, Durham, United Kingdom
| | | | - Paul William Denny
- Department of Biosciences, Lower Mountjoy, University of Durham, Durham, United Kingdom
| |
Collapse
|
19
|
Vallintine T, van Ooij C. Timing of dense granule biogenesis in asexual malaria parasites. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001389. [PMID: 37647112 PMCID: PMC10482371 DOI: 10.1099/mic.0.001389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
Malaria is an important infectious disease that continues to claim hundreds of thousands of lives annually. The disease is caused by infection of host erythrocytes by apicomplexan parasites of the genus Plasmodium. The parasite contains three different apical organelles - micronemes, rhoptries and dense granules (DGs) - whose contents are secreted to mediate binding to and invasion of the host cell and the extensive remodelling of the host cell that occurs following invasion. Whereas the roles of micronemes and rhoptries in binding and invasion of the host erythrocyte have been studied in detail, the roles of DGs in Plasmodium parasites are poorly understood. They have been proposed to control host cell remodelling through regulated protein secretion after invasion, but many basic aspects of the biology of DGs remain unknown. Here we describe DG biogenesis timing for the first time, using RESA localization as a proxy for the timing of DG formation. We show that DG formation commences approximately 37 min prior to schizont egress, as measured by the recruitment of the DG marker RESA. Furthermore, using a bioinformatics approach, we aimed to predict additional cargo of the DGs and identified the J-dot protein HSP40 as a DG protein, further supporting the very early role of these organelles in the interaction of the parasite with the host cell.
Collapse
Affiliation(s)
- Tansy Vallintine
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Christiaan van Ooij
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
20
|
Pulido-Quevedo FA, Arévalo-Pinzón G, Castañeda-Ramírez JJ, Barreto-Santamaría A, Patarroyo ME, Patarroyo MA. Plasmodium falciparum rhoptry neck protein 4 has conserved regions mediating interactions with receptors on human erythrocytes and hepatocyte membrane. Int J Med Microbiol 2023; 313:151579. [PMID: 37030083 DOI: 10.1016/j.ijmm.2023.151579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 03/25/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023] Open
Abstract
Plasmodium falciparum-related malaria represents a serious worldwide public health problem due to its high mortality rates. P. falciparum expresses rhoptry neck protein 4 (PfRON4) in merozoite and sporozoite rhoptries, it participates in tight junction-TJ formation via the AMA-1/RON complex and is refractory to complete genetic deletion. Despite this, which PfRON4 key regions interact with host cells remain unknown; such information would be useful for combating falciparum malaria. Thirty-two RON4 conserved region-derived peptides were chemically synthesised for determining and characterising PfRON4 regions having high host cell binding affinity (high activity binding peptides or HABPs). Receptor-ligand interaction/binding assays determined their specific binding capability, the nature of their receptors and their ability to inhibit in vitro parasite invasion. Peptides 42477, 42479, 42480, 42505 and 42513 had greater than 2% erythrocyte binding activity, whilst peptides 42477 and 42480 specifically bound to HepG2 membrane, both of them having micromolar and submicromolar range dissociation constants (Kd). Cell-peptide interaction was sensitive to treating erythrocytes with trypsin and/or chymotrypsin and HepG2 with heparinase I and chondroitinase ABC, suggesting protein-type (erythrocyte) and heparin and/or chondroitin sulphate proteoglycan receptors (HepG2) for PfRON4. Erythrocyte invasion inhibition assays confirmed HABPs' importance during merozoite invasion. PfRON4 800-819 (42477) and 860-879 (42480) regions specifically interacted with host cells, thereby supporting their inclusion in a subunit-based, multi-antigen, multistage anti-malarial vaccine.
Collapse
Affiliation(s)
- Fredy A Pulido-Quevedo
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50#26-20, Bogotá, Colombia; MSc programme in Biochemistry, Faculty of Medicine, Universidad Nacional de Colombia, Carrera 45 # 26-85, Bogotá, Colombia
| | - Gabriela Arévalo-Pinzón
- Microbiology Department, Faculty of Sciences, Pontificia Universidad Javeriana, Carrera 7 # 40-62, Bogotá, Colombia
| | - Jeimmy J Castañeda-Ramírez
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50#26-20, Bogotá, Colombia
| | - Adriana Barreto-Santamaría
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50#26-20, Bogotá, Colombia; Faculty of Sciences, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Calle 222 # 55-37, Bogotá, Colombia
| | - Manuel E Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50#26-20, Bogotá, Colombia; Health Sciences Division, Main Campus, Universidad Santo Tomás, Carrera 9 # 51-11, Bogotá, Colombia; Faculty of Medicine, Universidad Nacional de Colombia, Carrera 45 # 26-85, Bogotá, Colombia
| | - Manuel A Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50#26-20, Bogotá, Colombia; Health Sciences Division, Main Campus, Universidad Santo Tomás, Carrera 9 # 51-11, Bogotá, Colombia; Faculty of Medicine, Universidad Nacional de Colombia, Carrera 45 # 26-85, Bogotá, Colombia.
| |
Collapse
|
21
|
Elsworth B, Keroack C, Rezvani Y, Paul A, Barazorda K, Tennessen J, Sack S, Moreira C, Gubbels MJ, Meyers M, Zarringhalam K, Duraisingh M. Babesia divergens egress from host cells is orchestrated by essential and druggable kinases and proteases. RESEARCH SQUARE 2023:rs.3.rs-2553721. [PMID: 36909484 PMCID: PMC10002801 DOI: 10.21203/rs.3.rs-2553721/v1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Apicomplexan egress from host cells is fundamental to the spread of infection and is poorly characterized in Babesia spp., parasites of veterinary importance and emerging zoonoses. Through the use of video microscopy, transcriptomics and chemical genetics, we have implicated signaling, proteases and gliding motility as key drivers of egress by Babesia divergens. We developed reverse genetics to perform a knockdown screen of putative mediators of egress, identifying kinases and proteases involved in distinct steps of egress (ASP3, PKG and CDPK4) and invasion (ASP2, ASP3 and PKG). Inhibition of egress leads to continued intracellular replication, indicating exit from the replication cycle is uncoupled from egress. Chemical genetics validated PKG, ASP2 and ASP3 as druggable targets in Babesia spp. All taken together, egress in B. divergens more closely resembles T. gondii than the more evolutionarily-related Plasmodium spp. We have established a molecular framework for biological and translational studies of B. divergens egress.
Collapse
|
22
|
Defining species-specific and conserved interactions of apical membrane protein 1 during erythrocyte invasion in malaria to inform multi-species vaccines. Cell Mol Life Sci 2023; 80:74. [PMID: 36847896 PMCID: PMC9969379 DOI: 10.1007/s00018-023-04712-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/17/2023] [Accepted: 01/30/2023] [Indexed: 03/01/2023]
Abstract
Plasmodium falciparum and P. vivax are the major causes of human malaria, and P. knowlesi is an important additional cause in SE Asia. Binding of apical membrane antigen 1 (AMA1) to rhoptry neck protein 2 (RON2) was thought to be essential for merozoite invasion of erythrocytes by Plasmodium spp. Our findings reveal that P. falciparum and P. vivax have diverged and show species-specific binding of AMA1 to RON2, determined by a β-hairpin loop in RON2 and specific residues in AMA1 Loop1E. In contrast, cross-species binding of AMA1 to RON2 is retained between P. vivax and P. knowlesi. Mutation of specific amino acids in AMA1 Loop1E in P. falciparum or P. vivax ablated RON2 binding without impacting erythrocyte invasion. This indicates that the AMA1-RON2-loop interaction is not essential for invasion and additional AMA1 interactions are involved. Mutations in AMA1 that disrupt RON2 binding also enable escape of invasion inhibitory antibodies. Therefore, vaccines and therapeutics will need to be broader than targeting only the AMA1-RON2 interaction. Antibodies targeting AMA1 domain 3 had greater invasion-inhibitory activity when RON2-loop binding was ablated, suggesting this domain is a promising additional target for vaccine development. Targeting multiple AMA1 interactions involved in invasion may enable vaccines that generate more potent inhibitory antibodies and address the capacity for immune evasion. Findings on specific residues for invasion function and species divergence and conservation can inform novel vaccines and therapeutics against malaria caused by three species, including the potential for cross-species vaccines.
Collapse
|
23
|
Invasion of Toxoplasma gondii bradyzoites: Molecular dissection of the moving junction proteins and effective vaccination targets. Proc Natl Acad Sci U S A 2023; 120:e2219533120. [PMID: 36693095 PMCID: PMC9945962 DOI: 10.1073/pnas.2219533120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2L1, showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.
Collapse
|
24
|
Lee SK, Low LM, Andersen JF, Yeoh LM, Valenzuela Leon PC, Drew DR, Doehl JSP, Calvo E, Miller LH, Beeson JG, Gunalan K. The direct binding of Plasmodium vivax AMA1 to erythrocytes defines a RON2-independent invasion pathway. Proc Natl Acad Sci U S A 2023; 120:e2215003120. [PMID: 36577076 PMCID: PMC9910450 DOI: 10.1073/pnas.2215003120] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/19/2022] [Indexed: 12/29/2022] Open
Abstract
We used a transgenic parasite in which Plasmodium falciparum parasites were genetically modified to express Plasmodium vivax apical membrane antigen 1 (PvAMA1) protein in place of PfAMA1 to study PvAMA1-mediated invasion. In P. falciparum, AMA1 interaction with rhoptry neck protein 2 (RON2) is known to be crucial for invasion, and PfRON2 peptides (PfRON2p) blocked the invasion of PfAMA1 wild-type parasites. However, PfRON2p has no effect on the invasion of transgenic parasites expressing PvAMA1 indicating that PfRON2 had no role in the invasion of PvAMA1 transgenic parasites. Interestingly, PvRON2p blocked the invasion of PvAMA1 transgenic parasites in a dose-dependent manner. We found that recombinant PvAMA1 domains 1 and 2 (rPvAMA1) bound to reticulocytes and normocytes indicating that PvAMA1 directly interacts with erythrocytes during the invasion, and invasion blocking of PvRON2p may result from it interfering with PvAMA1 binding to erythrocytes. It was previously shown that the peptide containing Loop1a of PvAMA1 (PvAMA1 Loop1a) is also bound to reticulocytes. We found that the Loop1a peptide blocked the binding of PvAMA1 to erythrocytes. PvAMA1 Loop1a has no polymorphisms in contrast to other PvAMA1 loops and may be an attractive vaccine target. We thus present the evidence that PvAMA1 binds to erythrocytes in addition to interacting with PvRON2 suggesting that the P. vivax merozoites may exploit complex pathways during the invasion process.
Collapse
Affiliation(s)
- Seong-Kyun Lee
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - Leanne M. Low
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - John F. Andersen
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - Lee M. Yeoh
- Burnet Institute, Melbourne, VIC3004, Australia
| | - Paola Carolina Valenzuela Leon
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | | | - Johannes S. P. Doehl
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - Eric Calvo
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - Louis H. Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| | - James G. Beeson
- Burnet Institute, Melbourne, VIC3004, Australia
- Central Clinical School and Department of Microbiology, Monash University, VIC3004, Australia
- Department of Infectious Diseases, University of Melbourne, VIC3010, Australia
| | - Karthigayan Gunalan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD20852
| |
Collapse
|
25
|
Sparvoli D, Delabre J, Penarete‐Vargas DM, Kumar Mageswaran S, Tsypin LM, Heckendorn J, Theveny L, Maynadier M, Mendonça Cova M, Berry‐Sterkers L, Guérin A, Dubremetz J, Urbach S, Striepen B, Turkewitz AP, Chang Y, Lebrun M. An apical membrane complex for triggering rhoptry exocytosis and invasion in Toxoplasma. EMBO J 2022; 41:e111158. [PMID: 36245278 PMCID: PMC9670195 DOI: 10.15252/embj.2022111158] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 01/13/2023] Open
Abstract
Apicomplexan parasites possess secretory organelles called rhoptries that undergo regulated exocytosis upon contact with the host. This process is essential for the parasitic lifestyle of these pathogens and relies on an exocytic machinery sharing structural features and molecular components with free-living ciliates. However, how the parasites coordinate exocytosis with host interaction is unknown. Here, we performed a Tetrahymena-based transcriptomic screen to uncover novel exocytic factors in Ciliata and conserved in Apicomplexa. We identified membrane-bound proteins, named CRMPs, forming part of a large complex essential for rhoptry secretion and invasion in Toxoplasma. Using cutting-edge imaging tools, including expansion microscopy and cryo-electron tomography, we show that, unlike previously described rhoptry exocytic factors, TgCRMPs are not required for the assembly of the rhoptry secretion machinery and only transiently associate with the exocytic site-prior to the invasion. CRMPs and their partners contain putative host cell-binding domains, and CRMPa shares similarities with GPCR proteins. Collectively our data imply that the CRMP complex acts as a host-molecular sensor to ensure that rhoptry exocytosis occurs when the parasite contacts the host cell.
Collapse
Affiliation(s)
- Daniela Sparvoli
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Jason Delabre
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | | | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Lev M Tsypin
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
- Present address:
Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Justine Heckendorn
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Liam Theveny
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Marjorie Maynadier
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Marta Mendonça Cova
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Laurence Berry‐Sterkers
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jean‐François Dubremetz
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Serge Urbach
- IGFUniversité de Montpellier, CNRS, INSERMMontpellierFrance
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
| | - Yi‐Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Maryse Lebrun
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| |
Collapse
|
26
|
Molecular Assessment of Domain I of Apical Membrane Antigen I Gene in Plasmodium falciparum: Implications in Plasmodium Invasion, Taxonomy, Vaccine Development, and Drug Discovery. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2022; 2022:1419998. [PMID: 36249587 PMCID: PMC9568357 DOI: 10.1155/2022/1419998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 11/07/2022]
Abstract
Given its global morbidity and mortality rates, malaria continues to be a major public health concern. Despite significant progress in the fight against malaria, efforts to control and eradicate the disease globally are in jeopardy due to lack of a universal vaccine. The conserved short peptide sequences found in Domain I of Plasmodium falciparum apical membrane antigen 1 (PfAMA1), which are exposed on the parasite cell surface and in charge of Plasmodium falciparum invasion of host cells, make PfAMA1 a promising vaccine candidate antigen. The precise amino acids that make up these conserved short peptides are still unknown, and it is still difficult to pinpoint the molecular processes by which PfAMA1 interacts with the human host cell during invasion. The creation of a universal malaria vaccine based on the AMA1 antigen is challenging due to these knowledge limitations. This study used genome mining techniques to look for these particular short peptides in PfAMA1. Thirty individuals with Plasmodium falciparum malaria had blood samples taken using Whatman's filter papers. DNA from the parasite was taken out using the Chelex technique. Domain I of the Plasmodium falciparum AMA1 gene was amplified using nested polymerase chain reactions, and the amplified products were removed, purified, and sequenced. The DNA sequence generated was converted into the matching amino acid sequence using bioinformatic techniques. These amino acid sequences were utilized to search for antigenic epitopes, therapeutic targets, and conserved short peptides in Domain I of PfAMA1. The results of this investigation shed important light on the molecular mechanisms behind Plasmodium invasion of host cells, a potential PfAMA1 vaccine antigen sequence, and prospective malaria treatment options in the future. Our work offers fresh information on malaria medication and vaccine research that has not been previously discussed.
Collapse
|
27
|
Dos Santos Pacheco N, Brusini L, Haase R, Tosetti N, Maco B, Brochet M, Vadas O, Soldati-Favre D. Conoid extrusion regulates glideosome assembly to control motility and invasion in Apicomplexa. Nat Microbiol 2022; 7:1777-1790. [DOI: 10.1038/s41564-022-01212-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/22/2022] [Indexed: 12/18/2022]
|
28
|
A Role for Basigin in Toxoplasma gondii Infection. Infect Immun 2022; 90:e0020522. [PMID: 35913173 PMCID: PMC9387297 DOI: 10.1128/iai.00205-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The role of specific host cell surface receptors during Toxoplasma gondii invasion of host cells is poorly defined. Here, we interrogated the role of the well-known malarial invasion receptor, basigin, in T. gondii infection of astrocytes. We found that primary astrocytes express two members of the BASIGIN (BSG) immunoglobulin family, basigin and embigin, but did not express neuroplastin. Antibody blockade of either basigin or embigin caused a significant reduction of parasite infectivity in astrocytes. The specific role of basigin during T. gondii invasion was further examined using a mouse astrocytic cell line (C8-D30), which exclusively expresses basigin. CRISPR-mediated deletion of basigin in C8-D30 cells resulted in decreased T. gondii infectivity. T. gondii replication and invasion efficiency were not altered by basigin deficiency, but parasite attachment to astrocytes was markedly reduced. We also conducted a proteomic screen to identify T. gondii proteins that interact with basigin. Toxoplasma-encoded cyclophilins, the protein 14-3-3, and protein disulfide isomerase (TgPDI) were among the putative basigin-ligands identified. Recombinant TgPDI produced in E. coli bound to basigin and pretreatment of tachyzoites with a PDI inhibitor decreased parasite attachment to host cells. Finally, mutagenesis of the active site cysteines of TgPDI abolished enzyme binding to basigin. Thus, basigin and its related immunoglobulin family members may represent host receptors that mediate attachment of T. gondii to diverse cell types.
Collapse
|
29
|
Munera Lopez J, Tengganu IF, Liu J, Murray JM, Arias Padilla LF, Zhang Y, Brown PT, Florens L, Hu K. An apical protein, Pcr2, is required for persistent movement by the human parasite Toxoplasma gondii. PLoS Pathog 2022; 18:e1010776. [PMID: 35994509 PMCID: PMC9436145 DOI: 10.1371/journal.ppat.1010776] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 09/01/2022] [Accepted: 07/28/2022] [Indexed: 11/18/2022] Open
Abstract
The phylum Apicomplexa includes thousands of species of unicellular parasites that cause a wide range of human and animal diseases such as malaria and toxoplasmosis. To infect, the parasite must first initiate active movement to disseminate through tissue and invade into a host cell, and then cease moving once inside. The parasite moves by gliding on a surface, propelled by an internal cortical actomyosin-based motility apparatus. One of the most effective invaders in Apicomplexa is Toxoplasma gondii, which can infect any nucleated cell and any warm-blooded animal. During invasion, the parasite first makes contact with the host cell "head-on" with the apical complex, which features an elaborate cytoskeletal apparatus and associated structures. Here we report the identification and characterization of a new component of the apical complex, Preconoidal region protein 2 (Pcr2). Pcr2 knockout parasites replicate normally, but they are severely diminished in their capacity for host tissue destruction due to significantly impaired invasion and egress, two vital steps in the lytic cycle. When stimulated for calcium-induced egress, Pcr2 knockout parasites become active, and secrete effectors to lyse the host cell. Calcium-induced secretion of the major adhesin, MIC2, also appears to be normal. However, the movement of the Pcr2 knockout parasite is spasmodic, which drastically compromises egress. In addition to faulty motility, the ability of the Pcr2 knockout parasite to assemble the moving junction is impaired. Both defects likely contribute to the poor efficiency of invasion. Interestingly, actomyosin activity, as indicated by the motion of mEmerald tagged actin chromobody, appears to be largely unperturbed by the loss of Pcr2, raising the possibility that Pcr2 may act downstream of or in parallel with the actomyosin machinery.
Collapse
Affiliation(s)
- Jonathan Munera Lopez
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Isadonna F. Tengganu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Jun Liu
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - John M. Murray
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Luisa F. Arias Padilla
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Ying Zhang
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Peter T. Brown
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, Arizona, United States of America
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Ke Hu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| |
Collapse
|
30
|
Possenti A, Di Cristina M, Nicastro C, Lunghi M, Messina V, Piro F, Tramontana L, Cherchi S, Falchi M, Bertuccini L, Spano F. Functional Characterization of the Thrombospondin-Related Paralogous Proteins Rhoptry Discharge Factors 1 and 2 Unveils Phenotypic Plasticity in Toxoplasma gondii Rhoptry Exocytosis. Front Microbiol 2022; 13:899243. [PMID: 35756016 PMCID: PMC9218915 DOI: 10.3389/fmicb.2022.899243] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
To gain access to the intracellular cytoplasmic niche essential for their growth and replication, apicomplexan parasites such as Toxoplasma gondii rely on the timely secretion of two types of apical organelles named micronemes and rhoptries. Rhoptry proteins are key to host cell invasion and remodeling, however, the molecular mechanisms underlying the tight control of rhoptry discharge are poorly understood. Here, we report the identification and functional characterization of two novel T. gondii thrombospondin-related proteins implicated in rhoptry exocytosis. The two proteins, already annotated as MIC15 and MIC14, were renamed rhoptry discharge factor 1 (RDF1) and rhoptry discharge factor 2 (RDF2) and found to be exclusive of the Coccidia class of apicomplexan parasites. Furthermore, they were shown to have a paralogous relationship and share a C-terminal transmembrane domain followed by a short cytoplasmic tail. Immunofluorescence analysis of T. gondii tachyzoites revealed that RDF1 presents a diffuse punctate localization not reminiscent of any know subcellular compartment, whereas RDF2 was not detected. Using a conditional knockdown approach, we demonstrated that RDF1 loss caused a marked growth defect. The lack of the protein did not affect parasite gliding motility, host cell attachment, replication and egress, whereas invasion was dramatically reduced. Notably, while RDF1 depletion did not result in altered microneme exocytosis, rhoptry discharge was found to be heavily impaired. Interestingly, rhoptry secretion was reversed by spontaneous upregulation of the RDF2 gene in knockdown parasites grown under constant RDF1 repression. Collectively, our results identify RDF1 and RDF2 as additional key players in the pathway controlling rhoptry discharge. Furthermore, this study unveils a new example of compensatory mechanism contributing to phenotypic plasticity in T. gondii.
Collapse
Affiliation(s)
- Alessia Possenti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Chiara Nicastro
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Matteo Lunghi
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Valeria Messina
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Piro
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Lorenzo Tramontana
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Simona Cherchi
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Mario Falchi
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Furio Spano
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| |
Collapse
|
31
|
Cova MM, Lamarque MH, Lebrun M. How Apicomplexa Parasites Secrete and Build Their Invasion Machinery. Annu Rev Microbiol 2022; 76:619-640. [PMID: 35671531 DOI: 10.1146/annurev-micro-041320-021425] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Apicomplexa are obligatory intracellular parasites that sense and actively invade host cells. Invasion is a conserved process that relies on the timely and spatially controlled exocytosis of unique specialized secretory organelles termed micronemes and rhoptries. Microneme exocytosis starts first and likely controls the intricate mechanism of rhoptry secretion. To assemble the invasion machinery, micronemal proteins-associated with the surface of the parasite-interact and form complexes with rhoptry proteins, which in turn are targeted into the host cell. This review covers the molecular advances regarding microneme and rhoptry exocytosis and focuses on how the proteins discharged from these two compartments work in synergy to drive a successful invasion event. Particular emphasis is given to the structure and molecular components of the rhoptry secretion apparatus, and to the current conceptual framework of rhoptry exocytosis that may constitute an unconventional eukaryotic secretory machinery closely related to the one described in ciliates. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Marta Mendonça Cova
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
| | - Mauld H Lamarque
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
| | - Maryse Lebrun
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
| |
Collapse
|
32
|
Vigetti L, Labouré T, Roumégous C, Cannella D, Touquet B, Mayer C, Couté Y, Frénal K, Tardieux I, Renesto P. The BCC7 Protein Contributes to the Toxoplasma Basal Pole by Interfacing between the MyoC Motor and the IMC Membrane Network. Int J Mol Sci 2022; 23:5995. [PMID: 35682673 PMCID: PMC9181098 DOI: 10.3390/ijms23115995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022] Open
Abstract
T. gondii is a eukaryotic parasite that has evolved a stage called tachyzoite which multiplies in host cells by producing two daughter cells internally. These nascent tachyzoites bud off their mother and repeat the division process until the expanding progenies escape to settle and multiply in other host cells. Over these intra- and extra-cellular phases, the tachyzoite maintains an essential apicobasal polarity that emerges through a unique bidirectional budding process of the elongating cells. This process requires the assembly of several molecular complexes that, at the nascent pole, encompass structural and myosin motor elements. To characterize a recently identified basal pole marker named BCC7 with respect to the posterior myosin J and myosin C motors, we used conventional biochemistry as well as advanced proteomic and in silico analysis in conjunction with live and super resolution microscopy of transgenic fluorescent tachyzoites. We document that BCC7 forms a ribbed ring below which myosin C motor entities distribute regularly. In addition, we identified-among 13 BCC7 putative partners-two novel and five known members of the inner membrane complex (IMC) family which ends at the apical side of the ring. Therefore, BCC7 could assist the stabilization of the IMC plaques and contribute to the parasite biomechanical properties.
Collapse
Affiliation(s)
- Luis Vigetti
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France; (L.V.); (T.L.); (B.T.)
| | - Tatiana Labouré
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France; (L.V.); (T.L.); (B.T.)
| | - Chloé Roumégous
- Université de Bordeaux, Team Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, 33000 Bordeaux, France; (C.R.); (K.F.)
| | - Dominique Cannella
- IAB, Team Host-Pathogen Interactions & Immunity to Infection, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France;
| | - Bastien Touquet
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France; (L.V.); (T.L.); (B.T.)
| | - Claudine Mayer
- Université Paris Cité, 75013 Paris, France;
- ICube-UMR7357, CSTB, Centre de Recherche en Biomédecine de Strasbourg, 67084 Strasbourg, France
| | - Yohann Couté
- INSERM, University of Grenoble Alpes, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, 38000 Grenoble, France;
| | - Karine Frénal
- Université de Bordeaux, Team Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, 33000 Bordeaux, France; (C.R.); (K.F.)
| | - Isabelle Tardieux
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France; (L.V.); (T.L.); (B.T.)
| | - Patricia Renesto
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, 38700 Grenoble, France; (L.V.); (T.L.); (B.T.)
| |
Collapse
|
33
|
Xu J, Wang J, Li Z, He X, Zhao S, Ma Q, Li X, Liu J, Liu A, Li Y, Yin H, Luo J, Guan G. A universal ELISA assay for detecting six strains of ovine Babesia species in China. Vet Parasitol 2021; 300:109616. [PMID: 34781076 DOI: 10.1016/j.vetpar.2021.109616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 10/13/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Ovine babesiosis, caused by genus of Babesia, is a zoonotic disease and mainly transmitted by hard ticks. It has led to enormous economic losses to the sheep industry in China. In the present study, an ELISA assay for simultaneous detection six strains of Babesia spp., including B. motasi Lintan, B. motasi Tianzhu, B. motasi Hebei, B. motasi Ningxian, Babesia sp. Xinjiang and Babesia sp. Dunhuang, was developed using Apical Membrane Antigen 1 (AMA1) as candidate diagnostic antigen. The sensitivity and specificity of the established ELISA were 97.4 % and 98.0 %, respectively. Relatively high level of specific antibodies could be detected from 12th day to 126th day after sheep experimentally infected with Babesia spp.. A small scale of field sera was investigated using the developed ELISA assay, and the average positive rate was 51.98 %. This study provides an easy to operate, cost effective and time saving approach, which is suitable for both field and experimental samples, thus it could be a useful tool in epidemiological investigations and diagnoses of ovine babesiosis.
Collapse
Affiliation(s)
- Jianlin Xu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Jinming Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Zhi Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China; Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining, Qinghai, 810016, PR China
| | - Xin He
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Shuaiyang Zhao
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Quanying Ma
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Xuan Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Junlong Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Aihong Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Youquan Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China
| | - Hong Yin
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - Jianxun Luo
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China.
| | - Guiquan Guan
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu, 730046, PR China.
| |
Collapse
|
34
|
Proximity-Labeling Reveals Novel Host and Parasite Proteins at the Toxoplasma Parasitophorous Vacuole Membrane. mBio 2021; 12:e0026021. [PMID: 34749525 PMCID: PMC8576527 DOI: 10.1128/mbio.00260-21] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous, intracellular parasite that envelops its parasitophorous vacuole with a protein-laden membrane (PVM). The PVM is critical for interactions with the infected host cell, such as nutrient transport and immune defense. Only a few parasite and host proteins have so far been identified on the host-cytosolic side of the Toxoplasma PVM. We report here the use of human foreskin fibroblasts expressing the proximity-labeling enzyme miniTurbo, fused to a domain that targets it to this face of the PVM, in combination with quantitative proteomics to specifically identify proteins present at this interface. Out of numerous human and parasite proteins with candidate PVM localization, we validate three parasite proteins (TGGT1_269950 [GRA61], TGGT1_215360 [GRA62], and TGGT1_217530 [GRA63]) and four new host proteins (PDCD6IP/ALIX, PDCD6, CC2D1A, and MOSPD2) as localized to the PVM in infected human cells through immunofluorescence microscopy. These results significantly expand our knowledge of proteins present at the Toxoplasma PVM and, given that three of the validated host proteins are components of the ESCRT (endosomal sorting complexes required for transport) machinery, they further suggest that novel biology is operating at this crucial host-pathogen interface.
Collapse
|
35
|
Cialek CA, Galindo G, Koch AL, Saxton MN, Stasevich TJ. Bead Loading Proteins and Nucleic Acids into Adherent Human Cells. J Vis Exp 2021:10.3791/62559. [PMID: 34152325 PMCID: PMC9074699 DOI: 10.3791/62559] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Many live-cell imaging experiments use exogenous particles (e.g., peptides, antibodies, beads) to label or function within cells. However, introducing proteins into a cell across its membrane is difficult. The limited selection of current methods struggles with low efficiency, requires expensive and technically demanding equipment, or functions within narrow parameters. Here, we describe a relatively simple and cost-effective technique for loading DNA, RNA, and proteins into live human cells. Bead loading induces a temporary mechanical disruption to the cell membrane, allowing macromolecules to enter adherent, live mammalian cells. At less than 0.01 USD per experiment, bead loading is the least expensive cell loading method available. Moreover, bead loading does not substantially stress cells or impact their viability or proliferation. This manuscript describes the steps of the bead loading procedure, adaptations, variations, and technical limitations. This methodology is especially suited for live-cell imaging but provides a practical solution for other applications requiring the introduction of proteins, beads, RNA, or plasmids into living, adherent mammalian cells.
Collapse
Affiliation(s)
| | - Gabriel Galindo
- Department of Biochemistry and Molecular Biology, Colorado State University
| | - Amanda Lynn Koch
- Department of Biochemistry and Molecular Biology, Colorado State University
| | | | - Timothy John Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University; World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology;
| |
Collapse
|
36
|
Shakya B, Patel SD, Tani Y, Egan ES. Erythrocyte CD55 mediates the internalization of Plasmodium falciparum parasites. eLife 2021; 10:61516. [PMID: 34028351 PMCID: PMC8184214 DOI: 10.7554/elife.61516] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 05/20/2021] [Indexed: 01/04/2023] Open
Abstract
Invasion of human erythrocytes by the malaria parasite Plasmodium falciparum is a multi-step process. Previously, a forward genetic screen for P. falciparum host factors identified erythrocyte CD55 as essential for invasion, but its specific role and how it interfaces with the other factors that mediate this complex process are unknown. Using CRISPR-Cas9 editing, antibody-based inhibition, and live cell imaging, here we show that CD55 is specifically required for parasite internalization. Pre-invasion kinetics, erythrocyte deformability, and echinocytosis were not influenced by CD55, but entry was inhibited when CD55 was blocked or absent. Visualization of parasites attached to CD55-null erythrocytes points to a role for CD55 in stability and/or progression of the moving junction. Our findings demonstrate that CD55 acts after discharge of the parasite’s rhoptry organelles, and plays a unique role relative to all other invasion receptors. As the requirement for CD55 is strain-transcendent, these results suggest that CD55 or its interacting partners may hold potential as therapeutic targets for malaria.
Collapse
Affiliation(s)
- Bikash Shakya
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, United States
| | - Saurabh D Patel
- Zuckerman Institute, Columbia University, New York City, United States
| | | | - Elizabeth S Egan
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, United States
| |
Collapse
|
37
|
Ben Chaabene R, Lentini G, Soldati-Favre D. Biogenesis and discharge of the rhoptries: Key organelles for entry and hijack of host cells by the Apicomplexa. Mol Microbiol 2021; 115:453-465. [PMID: 33368727 DOI: 10.1111/mmi.14674] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/17/2020] [Accepted: 12/19/2020] [Indexed: 12/14/2022]
Abstract
Rhoptries are specialized secretory organelles found in the Apicomplexa phylum, playing a central role in the establishment of parasitism. The rhoptry content includes membranous as well as proteinaceous materials that are discharged into the host cell in a regulated fashion during parasite entry. A set of rhoptry neck proteins form a RON complex that critically participates in the moving junction formation during invasion. Some of the rhoptry bulb proteins are associated with the membranous materials and contribute to the formation of the parasitophorous vacuole membrane while others are targeted into the host cell including the nucleus to subvert cellular functions. Here, we review the recent studies on Toxoplasma and Plasmodium parasites that shed light on the key steps leading to rhoptry biogenesis, trafficking, and discharge.
Collapse
Affiliation(s)
- Rouaa Ben Chaabene
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Gaëlle Lentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| |
Collapse
|
38
|
Morshedi Rad D, Alsadat Rad M, Razavi Bazaz S, Kashaninejad N, Jin D, Ebrahimi Warkiani M. A Comprehensive Review on Intracellular Delivery. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005363. [PMID: 33594744 DOI: 10.1002/adma.202005363] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/22/2020] [Indexed: 05/22/2023]
Abstract
Intracellular delivery is considered an indispensable process for various studies, ranging from medical applications (cell-based therapy) to fundamental (genome-editing) and industrial (biomanufacture) approaches. Conventional macroscale delivery systems critically suffer from such issues as low cell viability, cytotoxicity, and inconsistent material delivery, which have opened up an interest in the development of more efficient intracellular delivery systems. In line with the advances in microfluidics and nanotechnology, intracellular delivery based on micro- and nanoengineered platforms has progressed rapidly and held great promises owing to their unique features. These approaches have been advanced to introduce a smorgasbord of diverse cargoes into various cell types with the maximum efficiency and the highest precision. This review differentiates macro-, micro-, and nanoengineered approaches for intracellular delivery. The macroengineered delivery platforms are first summarized and then each method is categorized based on whether it employs a carrier- or membrane-disruption-mediated mechanism to load cargoes inside the cells. Second, particular emphasis is placed on the micro- and nanoengineered advances in the delivery of biomolecules inside the cells. Furthermore, the applications and challenges of the established and emerging delivery approaches are summarized. The topic is concluded by evaluating the future perspective of intracellular delivery toward the micro- and nanoengineered approaches.
Collapse
Affiliation(s)
- Dorsa Morshedi Rad
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Maryam Alsadat Rad
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Sajad Razavi Bazaz
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Navid Kashaninejad
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Dayong Jin
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Majid Ebrahimi Warkiani
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
- Institute of Molecular Medicine, Sechenov University, Moscow, 119991, Russia
| |
Collapse
|
39
|
Cai YC, Yang CL, Hu W, Song P, Xu B, Lu Y, Ai L, Chu YH, Chen MX, Chen JX, Chen SH. Molecular Characterization and Immunological Evaluation of Truncated Babesia microti Rhoptry Neck Protein 2 as a Vaccine Candidate. Front Immunol 2021; 12:616343. [PMID: 33717108 PMCID: PMC7943735 DOI: 10.3389/fimmu.2021.616343] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
Babesia microti is a protozoan that infects red blood cells. Babesiosis is becoming a new global threat impacting human health. Rhoptry neck proteins (RONs) are proteins located at the neck of the rhoptry and studies indicate that these proteins play an important role in the process of red blood cell invasion. In the present study, we report on the bioinformatic analysis, cloning, and recombinant gene expression of two truncated rhoptry neck proteins 2 (BmRON2), as well as their potential for incorporation in a candidate vaccine for babesiosis. Western blot and immunofluorescence antibody (IFA) assays were performed to detect the presence of specific antibodies against BmRON2 in infected mice and the localization of N-BmRON2 in B. microti parasites. In vitro experiments were carried out to investigate the role of BmRON2 proteins during the B. microti invasion process and in vivo experiments to investigate immunoprotection. Homologous sequence alignment and molecular phylogenetic analysis indicated that BmRON2 showed similarities with RON2 proteins of other Babesia species. We expressed the truncated N-terminal (33-336 aa, designated rN-BmRON2) and C-terminal (915-1171 aa, designated rC-BmRON2) fragments of the BmRON2 protein, with molecular weights of 70 and 29 kDa, respectively. Western blot assays showed that the native BmRON2 protein is approximately 170 kDa, and that rN-BmRON2 was recognized by serum of mice experimentally infected with B. microti. Immunofluorescence analysis indicated that the BmRON2 protein was located at the apical end of merozoites, at the opposite end of the nucleus. In vitro red blood cell invasion inhibition studies with B. microti rBmRON2 proteins showed that relative invasion rate of rN-BmRON2 and rC-BmRON2 group is 45 and 56%, respectively. Analysis of the host immune response after immunization and B. microti infection showed that both rN-BmRON2 and rC-BmRON2 enhanced the immune response, but that rN-BmRON2 conferred better protection than rC-BmRON2. In conclusion, our results indicate that truncated rhoptry neck protein 2, especially its N-terminal fragment (rN-BmRON2), plays an important role in the invasion of host red blood cells, confers immune protection, and shows good potential as a candidate vaccine against babesiosis.
Collapse
Affiliation(s)
- Yu chun Cai
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Chun li Yang
- Department of Clinical Research, The 903rd Hospital of PLA, Hangzhou, China
| | - Wei Hu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
- School of Life Sciences, Fudan University, Shanghai, China
| | - Peng Song
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Bin Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Yan Lu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Lin Ai
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Yan hong Chu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Mu xin Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Jia xu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Shao hong Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Laboratory of Parasite and Vector Biology, Ministry of Public Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| |
Collapse
|
40
|
Carmeille R, Schiano Lomoriello P, Devarakonda PM, Kellermeier JA, Heaslip AT. Actin and an unconventional myosin motor, TgMyoF, control the organization and dynamics of the endomembrane network in Toxoplasma gondii. PLoS Pathog 2021; 17:e1008787. [PMID: 33529198 PMCID: PMC7880465 DOI: 10.1371/journal.ppat.1008787] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/12/2021] [Accepted: 01/07/2021] [Indexed: 12/25/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that relies on three distinct secretory organelles, the micronemes, rhoptries, and dense granules, for parasite survival and disease pathogenesis. Secretory proteins destined for these organelles are synthesized in the endoplasmic reticulum (ER) and sequentially trafficked through a highly polarized endomembrane network that consists of the Golgi and multiple post-Golgi compartments. Currently, little is known about how the parasite cytoskeleton controls the positioning of the organelles in this pathway, or how vesicular cargo is trafficked between organelles. Here we show that F-actin and an unconventional myosin motor, TgMyoF, control the dynamics and organization of the organelles in the secretory pathway, specifically ER tubule movement, apical positioning of the Golgi and post-Golgi compartments, apical positioning of the rhoptries, and finally, the directed transport of Rab6-positive and Rop1-positive vesicles. Thus, this study identifies TgMyoF and actin as the key cytoskeletal components that organize the endomembrane system in T. gondii. Endomembrane trafficking is a vital cellular process in all eukaryotic cells. In most cases the molecular motors myosin, kinesin, and dynein transport cargo including vesicles, organelles and transcripts along actin and microtubule filaments in a manner analogous to a train moving on its tracks. For the unicellular eukaryote Toxoplasma gondii, the accurate trafficking of proteins through the endomembrane system is vital for parasite survival and pathogenicity. However, the mechanisms of cargo transport in this parasite are poorly understood. In this study, we fluorescently labeled multiple endomembrane organelles and imaged their movements using live cell microscopy. We demonstrate that filamentous actin and an unconventional myosin motor named TgMyoF control both the positioning of organelles in this pathway and the movement of transport vesicles throughout the parasite cytosol. This data provides new insight into the mechanisms of cargo transport in this important pathogen and expands our understanding of the biological roles of actin in the intracellular phase of the parasite’s growth cycle.
Collapse
Affiliation(s)
- Romain Carmeille
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Porfirio Schiano Lomoriello
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Parvathi M. Devarakonda
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Jacob A. Kellermeier
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Aoife T. Heaslip
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail:
| |
Collapse
|
41
|
McGovern OL, Rivera-Cuevas Y, Carruthers VB. Emerging Mechanisms of Endocytosis in Toxoplasma gondii. Life (Basel) 2021; 11:life11020084. [PMID: 33503859 PMCID: PMC7911406 DOI: 10.3390/life11020084] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 02/07/2023] Open
Abstract
Eukaryotes critically rely on endocytosis of autologous and heterologous material to maintain homeostasis and to proliferate. Although mechanisms of endocytosis have been extensively identified in mammalian and plant systems along with model systems including budding yeast, relatively little is known about endocytosis in protozoan parasites including those belonging to the phylum Apicomplexa. Whereas it has been long established that the apicomplexan agents of malaria (Plasmodium spp.) internalize and degrade hemoglobin from infected red blood cells to acquire amino acids for growth, that the related and pervasive parasite Toxoplasma gondii has a functional and active endocytic system was only recently discovered. Here we discuss emerging and hypothesized mechanisms of endocytosis in Toxoplasma gondii with reference to model systems and malaria parasites. Establishing a framework for potential mechanisms of endocytosis in Toxoplasma gondii will help guide future research aimed at defining the molecular basis and biological relevance of endocytosis in this tractable and versatile parasite.
Collapse
|
42
|
Wang Q, Zhu S, Zhao Q, Huang B, Yu S, Yu Y, Liang S, Wang H, Zhao H, Han H, Dong H. Identification and Characterization of a Novel Apical Membrane Antigen 3 in Eimeria tenella. J Eukaryot Microbiol 2021; 68:e12836. [PMID: 33289220 DOI: 10.1111/jeu.12836] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022]
Abstract
Eimeria tenella is an obligate intracellular parasite in the phylum Apicomplexa. As described for other members of Apicomplexa, apical membrane antigen 1 (AMA1) has been shown to be critical for sporozoite invasion of host cells by E. tenella. Recently, an E. tenella paralogue of AMA1 (EtAMA1), dubbed sporoAMA1 (EtAMA3), was identified in proteomic and transcriptomic analyses of E. tenella, but not further characterized. Here, we show that EtAMA3 is a type I integral membrane protein that has 24% -38% identity with other EtAMAs. EtAMA3 has the same pattern of Cys residues in domains I and II of AMA1 orthologs from apicomplexan parasites, but high variance in domain III, with all six invariant Cys residues absent. EtAMA3 expression was developmentally regulated at the mRNA and protein levels. EtAMA3 protein was detected in sporulated oocysts and sporozoites, but not in the unsporulated oocysts or second-generation merozoites. EtAMA3 is secreted by micronemes and is primarily localized to the apical end of sporozoites during host-cell invasion. Additionally, pretreatment of sporozoites with rEtAMA3-specific antibodies substantially impeded their invasion into host cells. These results suggest EtAMA3 is a sporozoite-specific protein that is involved in host-cell sporozoite invasion.
Collapse
Affiliation(s)
- Qingjie Wang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Shunhai Zhu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Qiping Zhao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Bing Huang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Shuilan Yu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Yu Yu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Shanshan Liang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Haixia Wang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Huanzhi Zhao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Hongyu Han
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| | - Hui Dong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China
| |
Collapse
|
43
|
Wang Q, Zhao Q, Zhu S, Huang B, Yu S, Liang S, Wang H, Zhao H, Han H, Dong H. Further investigation of the characteristics and biological function of Eimeria tenella apical membrane antigen 1. ACTA ACUST UNITED AC 2020; 27:70. [PMID: 33306022 PMCID: PMC7731912 DOI: 10.1051/parasite/2020068] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/20/2020] [Indexed: 12/20/2022]
Abstract
Apical membrane antigen 1 (AMA1) is a type I integral membrane protein that is highly conserved in apicomplexan parasites. Previous studies have shown that Eimeria tenella AMA1 (EtAMA1) is critical for sporozoite invasion of host cells. Here, we show that EtAMA1 is a microneme protein secreted by sporozoites, confirming previous results. Individual and combined treatment with antibodies of EtAMA1 and its interacting proteins, E. tenella rhoptry neck protein 2 (EtRON2) and Eimeria-specific protein (EtESP), elicited significant anti-invasion effects on the parasite in a concentration-dependent manner. The overexpression of EtAMA1 in DF-1 cells showed a significant increase of sporozoite invasion. Isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS were used to screen differentially expressed proteins (DEPs) in DF-1 cells transiently transfected with EtAMA1. In total, 3953 distinct nonredundant proteins were identified and 163 of these were found to be differentially expressed, including 91 upregulated proteins and 72 downregulated proteins. The DEPs were mainly localized within the cytoplasm and were involved in protein binding and poly(A)-RNA binding. KEEG analyses suggested that the key pathways that the DEPs belonged to included melanogenesis, spliceosomes, tight junctions, and the FoxO and MAPK signaling pathways. The data in this study not only provide a comprehensive dataset for the overall protein changes caused by EtAMA1 expression, but also shed light on EtAMA1’s potential molecular mechanisms during Eimeria infections.
Collapse
Affiliation(s)
- Qingjie Wang
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Qiping Zhao
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Shunhai Zhu
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Bing Huang
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Shuilan Yu
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Shanshan Liang
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Haixia Wang
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Huanzhi Zhao
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Hongyu Han
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| | - Hui Dong
- Key Laboratory of Animal Parasitology of the Ministry of Agriculture, Shanghai Veterinary Research Institute, CAAS, 200241 Shanghai, PR China
| |
Collapse
|
44
|
Tartarelli I, Tinari A, Possenti A, Cherchi S, Falchi M, Dubey JP, Spano F. During host cell traversal and cell-to-cell passage, Toxoplasma gondii sporozoites inhabit the parasitophorous vacuole and posteriorly release dense granule protein-associated membranous trails. Int J Parasitol 2020; 50:1099-1115. [PMID: 32882286 DOI: 10.1016/j.ijpara.2020.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/21/2020] [Accepted: 06/23/2020] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii has a worldwide distribution and infects virtually all warm-blooded animals, including humans. Ingestion of the environmentally resistant oocyst stage, excreted only in the feces of cats, is central to transmission of this apicomplexan parasite. There is vast literature on the host and T. gondii tachyzoite (proliferative stage of the parasite) but little is known of the host-parasite interaction and conversion of the free-living stage (sporozoite inside the oocyst) to the parasitic stage. Here, we present events that follow invasion of host cells with T. gondii sporozoites by using immunofluorescence (IF) and transmission electron microscopy (TEM). Several human type cell cultures were infected with T. gondii sporozoites of the two genotypes (Type II, ME49 and Type III, VEG) most prevalent worldwide. For the first known time, using anti-rhoptry neck protein 4 (RON4) antibodies, the moving junction was visualized in sporozoites during the invasion process and shortly after its completion. Surprisingly, IF and TEM evaluation revealed that intracellular sporozoites release, at their posterior end, long membranous tails, herein named sporozoite-specific trails (SSTs). Differential permeabilization and IF experiments showed that the SSTs are associated with several dense granule proteins (GRAs) and that their membranous component is of parasite origin. Furthermore, TEM observations demonstrated that SST-associated sporozoites are delimited by a typical parasitophorous vacuole, which is retained during parasite exit from the host cell and during cell-to-cell passage. Our data strongly suggest that host cell traversal by T. gondii sporozoites relies on a novel force-producing mechanism, based on the massive extrusion at the parasite posterior pole of GRA-associated membranous material derived from the same pool of membranes forming the intravacuolar network.
Collapse
Affiliation(s)
- Irene Tartarelli
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Antonella Tinari
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Alessia Possenti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Simona Cherchi
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Mario Falchi
- National AIDS Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Jitender P Dubey
- U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland 20705, United States
| | - Furio Spano
- Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
| |
Collapse
|
45
|
Detection of the Rhoptry Neck Protein Complex in Plasmodium Sporozoites and Its Contribution to Sporozoite Invasion of Salivary Glands. mSphere 2020; 5:5/4/e00325-20. [PMID: 32817376 PMCID: PMC7440843 DOI: 10.1128/msphere.00325-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Sporozoites are the motile infectious stage that mediates malaria parasite transmission from mosquitoes to the mammalian host. This study addresses the question whether the rhoptry neck protein complex forms and functions in sporozoites, in addition to its role in merozoites. By applying coimmunoprecipitation and sporozoite stage-specific gene knockdown assays, it was demonstrated that RON2, RON4, and RON5 form a complex and are involved in sporozoite invasion of salivary glands via their attachment ability. These findings shed light on the conserved invasion mechanisms among apicomplexan infective stages. In addition, the sporozoite stage-specific gene knockdown system has revealed for the first time in Plasmodium that the RON2 and RON4 interaction reciprocally affects their stability and trafficking to rhoptries. Our study raises the possibility that the RON complex functions during sporozoite maturation as well as migration toward and invasion of target cells. In the Plasmodium life cycle, two infectious stages of parasites, merozoites and sporozoites, share rhoptry and microneme apical structures. A crucial step during merozoite invasion of erythrocytes is the discharge to the host cell membrane of some rhoptry neck proteins as a complex, followed by the formation of a moving junction involving the parasite-secreted protein AMA1 on the parasite membrane. Components of the merozoite rhoptry neck protein complex are also expressed in sporozoites, namely, RON2, RON4, and RON5, suggesting that invasion mechanism elements might be conserved between these infective stages. Recently, we demonstrated that RON2 is required for sporozoite invasion of mosquito salivary gland cells and mammalian hepatocytes, using a sporozoite stage-specific gene knockdown strategy in the rodent malaria parasite model, Plasmodium berghei. Here, we use a coimmunoprecipitation assay and oocyst-derived sporozoite extracts to demonstrate that RON2, RON4, and RON5 also form a complex in sporozoites. The sporozoite stage-specific gene knockdown strategy revealed that both RON4 and RON5 have crucial roles during sporozoite invasion of salivary glands, including a significantly reduced attachment ability required for the onset of gliding. Further analyses indicated that RON2 and RON4 reciprocally affect trafficking to rhoptries in developing sporozoites, while RON5 is independently transported. These findings indicate that the interaction between RON2 and RON4 contributes to their stability and trafficking to rhoptries, in addition to involvement in sporozoite attachment. IMPORTANCE Sporozoites are the motile infectious stage that mediates malaria parasite transmission from mosquitoes to the mammalian host. This study addresses the question whether the rhoptry neck protein complex forms and functions in sporozoites, in addition to its role in merozoites. By applying coimmunoprecipitation and sporozoite stage-specific gene knockdown assays, it was demonstrated that RON2, RON4, and RON5 form a complex and are involved in sporozoite invasion of salivary glands via their attachment ability. These findings shed light on the conserved invasion mechanisms among apicomplexan infective stages. In addition, the sporozoite stage-specific gene knockdown system has revealed for the first time in Plasmodium that the RON2 and RON4 interaction reciprocally affects their stability and trafficking to rhoptries. Our study raises the possibility that the RON complex functions during sporozoite maturation as well as migration toward and invasion of target cells.
Collapse
|
46
|
Dos Santos Pacheco N, Tosetti N, Koreny L, Waller RF, Soldati-Favre D. Evolution, Composition, Assembly, and Function of the Conoid in Apicomplexa. Trends Parasitol 2020; 36:688-704. [DOI: 10.1016/j.pt.2020.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 12/14/2022]
|
47
|
Smith JR, Ashander LM, Arruda SL, Cordeiro CA, Lie S, Rochet E, Belfort R, Furtado JM. Pathogenesis of ocular toxoplasmosis. Prog Retin Eye Res 2020; 81:100882. [PMID: 32717377 DOI: 10.1016/j.preteyeres.2020.100882] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022]
Abstract
Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.
Collapse
Affiliation(s)
- Justine R Smith
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA.
| | - Liam M Ashander
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
| | - Sigrid L Arruda
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Cynthia A Cordeiro
- Cordeiro et Costa Ophtalmologie, Campos dos Goytacazes, Brazil; Formerly of Department of Ophthalmology, Federal University of Minas Gerais School of Medicine, Belo Horizonte, Brazil
| | - Shervi Lie
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Elise Rochet
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Rubens Belfort
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - João M Furtado
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
| |
Collapse
|
48
|
Toxoplasma gondii Recombinant Antigens in the Serodiagnosis of Toxoplasmosis in Domestic and Farm Animals. Animals (Basel) 2020; 10:ani10081245. [PMID: 32707821 PMCID: PMC7459674 DOI: 10.3390/ani10081245] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
Simple Summary The very common parasite infections in animals are caused by members of Apicomplexa, including Toxoplasma gondii, Neospora sp., and Sarcocystis sp. These parasites pose serious veterinary problems. For example, the development of unambiguous diagnostic algorithms and determining the correct diagnosis are hindered by the similar antigenic structure of these parasites, as well as the multitude of similar disease symptoms presented in an infected animal. The intracellular parasite, T. gondii, infects a wide range of warm-blooded animals, including humans. This parasite is widespread among different animal populations, contributes to the loss of reproductive and malformations in young individuals, and can become a serious economic concern for farmers. Additionally, the consumption of undercooked or raw meat and the consumption of improperly processed milk product derived from farm animals are the main parasite transmission routes in humans. This work reviews potential improvements to diagnostic techniques that use recombinant antigens for serodiagnosis of toxoplasmosis in various species of animals. Abstract Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, and is a parasitic disease that occurs in all warm-blooded animals, including humans. Toxoplasmosis is one of the most common parasitic diseases of animals and results in reproductive losses. Toxoplasmosis in humans is usually caused by eating raw or undercooked meat or consuming dairy products containing the parasite. Diagnosis of toxoplasmosis is currently based on serological assays using native antigens to detect specific anti-T. gondii antibodies. Due to the high price, the available commercial agglutination assays are not suited to test a large number of animal serum samples. The recent development of proteomics elucidated the antigenic structure of T. gondii and enabled the development of various recombinant antigens that can be used in new, cheaper, and more effective diagnostic tools. Continuous development of scientific disciplines, such as molecular biology and genetic engineering, allows for the production of new recombinant antigens and provides the basis for new diagnostic tests for the detection of anti-T. gondii antibodies in animal serum samples.
Collapse
|
49
|
Hotspots in Plasmodium and RBC Receptor-Ligand Interactions: Key Pieces for Inhibiting Malarial Parasite Invasion. Int J Mol Sci 2020; 21:ijms21134729. [PMID: 32630804 PMCID: PMC7370042 DOI: 10.3390/ijms21134729] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/15/2020] [Accepted: 05/24/2020] [Indexed: 11/17/2022] Open
Abstract
Protein-protein interactions (IPP) play an essential role in practically all biological processes, including those related to microorganism invasion of their host cells. It has been found that a broad repertoire of receptor-ligand interactions takes place in the binding interphase with host cells in malaria, these being vital interactions for successful parasite invasion. Several trials have been conducted for elucidating the molecular interface of interactions between some Plasmodium falciparum and Plasmodium vivax antigens with receptors on erythrocytes and/or reticulocytes. Structural information concerning these complexes is available; however, deeper analysis is required for correlating structural, functional (binding, invasion, and inhibition), and polymorphism data for elucidating new interaction hotspots to which malaria control methods can be directed. This review describes and discusses recent structural and functional details regarding three relevant interactions during erythrocyte invasion: Duffy-binding protein 1 (DBP1)–Duffy antigen receptor for chemokines (DARC); reticulocyte-binding protein homolog 5 (PfRh5)-basigin, and erythrocyte binding antigen 175 (EBA175)-glycophorin A (GPA).
Collapse
|
50
|
Gunalan K, Gao X, Yap SSL, Lai SK, Ravasio A, Ganesan S, Li HY, Preiser PR. A processing product of the Plasmodium falciparum reticulocyte binding protein RH1 shows a close association with AMA1 during junction formation. Cell Microbiol 2020; 22:e13232. [PMID: 32452132 DOI: 10.1111/cmi.13232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/14/2020] [Accepted: 05/16/2020] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum responsible for the most virulent form of malaria invades human erythrocytes through multiple ligand-receptor interactions. The P. falciparum reticulocyte binding protein homologues (PfRHs) are expressed at the apical end of merozoites and form interactions with distinct erythrocyte surface receptors that are important for invasion. Here using a range of monoclonal antibodies (mAbs) against different regions of PfRH1 we have investigated the role of PfRH processing during merozoite invasion. We show that PfRH1 gets differentially processed during merozoite maturation and invasion and provide evidence that the different PfRH1 processing products have distinct functions during invasion. Using in-situ Proximity Ligation and FRET assays that allow probing of interactions at the nanometre level we show that a subset of PfRH1 products form close association with micronemal proteins Apical Membrane Antigen 1 (AMA1) in the moving junction suggesting a critical role in facilitating junction formation and active invasion. Our data provides evidence that time dependent processing of PfRH proteins is a mechanism by which the parasite is able to regulate distinct functional activities of these large processes. The identification of a specific close association with AMA1 in the junction now may also provide new avenues to target these interactions to prevent merozoite invasion.
Collapse
Affiliation(s)
- Karthigayan Gunalan
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Xiaohong Gao
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sally Shu Lin Yap
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Soak Kuan Lai
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Andrea Ravasio
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Institute of Biological and Medical Engineering of the Pontifical Catholic University of Chile, Chile
| | - Sundar Ganesan
- Research Technology Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Hoi Yeung Li
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Peter R Preiser
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|