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Santa MA, Umhang G, Klein C, Grant DM, Ruckstuhl KE, Musiani M, Gilleard JS, Massolo A. It's a small world for parasites: evidence supporting the North American invasion of European Echinococcus multilocularis. Proc Biol Sci 2023; 290:20230128. [PMID: 36883278 PMCID: PMC9993045 DOI: 10.1098/rspb.2023.0128] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Echinococcus multilocularis (Em), the causative agent of human alveolar echinococcosis (AE), is present in the Holarctic region, and several genetic variants deem to have differential infectivity and pathogenicity. An unprecedented outbreak of human AE cases in Western Canada infected with a European-like strain circulating in wild hosts warranted assessment of whether this strain was derived from a recent invasion or was endemic but undetected. Using nuclear and mitochondrial markers, we investigated the genetic diversity of Em in wild coyotes and red foxes from Western Canada, compared the genetic variants identified to global isolates and assessed their spatial distribution to infer possible invasion dynamics. Genetic variants from Western Canada were closely related to the original European clade, with lesser genetic diversity than that expected for a long-established strain and spatial genetic discontinuities within the study area, supporting the hypothesis of a relatively recent invasion with various founder events.
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Affiliation(s)
- Maria A. Santa
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
| | - Gerald Umhang
- Nancy Laboratory for Rabies and Wildlife, National Reference Laboratory for Echinococcus spp., Wildlife Surveillance and Eco-epidemiology Unit, ANSES, Technopôle Agricole et Vétérinaire, Malzéville, France
| | - Claudia Klein
- Department of Clinical and Veterinary Clinical Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
- Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Federal Research Institute for Animal Health, Neustadt, Germany
| | - Danielle M. Grant
- Department of Clinical and Veterinary Clinical Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
- NORCE Climate, NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway
| | - Kathreen E. Ruckstuhl
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
| | - Marco Musiani
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA), University of Bologna, Italy
| | - John S. Gilleard
- Department of Comparative Biology & Experimental Medicine, Host-Parasite Interactions (HPI) program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Alessandro Massolo
- Ethology Unit, Department of Biology, University of Pisa, Pisa, Italy
- UMR CNRS 6249 Chrono-environnement, Université Bourgogne Franche-Comté, Besançon, France
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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2
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Tamim El Jarkass H, Mok C, Schertzberg MR, Fraser AG, Troemel ER, Reinke AW. An intestinally secreted host factor promotes microsporidia invasion of C. elegans. eLife 2022; 11:72458. [PMID: 34994689 PMCID: PMC8806185 DOI: 10.7554/elife.72458] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/06/2022] [Indexed: 12/11/2022] Open
Abstract
Microsporidia are ubiquitous obligate intracellular pathogens of animals. These parasites often infect hosts through an oral route, but little is known about the function of host intestinal proteins that facilitate microsporidia invasion. To identify such factors necessary for infection by Nematocida parisii, a natural microsporidian pathogen of Caenorhabditis elegans, we performed a forward genetic screen to identify mutant animals that have a Fitness Advantage with Nematocida (Fawn). We isolated four fawn mutants that are resistant to Nematocida infection and contain mutations in T14E8.4, which we renamed aaim-1 (Antibacterial and Aids invasion by Microsporidia). Expression of AAIM-1 in the intestine of aaim-1 animals restores N. parisii infectivity and this rescue of infectivity is dependent upon AAIM-1 secretion. N. parisii spores in aaim-1 animals are improperly oriented in the intestinal lumen, leading to reduced levels of parasite invasion. Conversely, aaim-1 mutants display both increased colonization and susceptibility to the bacterial pathogen Pseudomonas aeruginosa and overexpression ofaaim-1 reduces P. aeruginosa colonization. Competitive fitness assays show that aaim-1 mutants are favored in the presence of N. parisii but disadvantaged on P. aeruginosa compared to wild-type animals. Together, this work demonstrates how microsporidia exploits a secreted protein to promote host invasion. Our results also suggest evolutionary trade-offs may exist to optimizing host defense against multiple classes of pathogens.
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Affiliation(s)
| | - Calvin Mok
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | | | - Andrew G Fraser
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Emily R Troemel
- Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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Oliveira ACS, Rezende L, Gorshkov V, Melo-Braga MN, Verano-Braga T, Fernandes-Braga W, Guadalupe JLDM, de Menezes GB, Kjeldsen F, de Andrade HM, Andrade LDO. Biological and Molecular Effects of Trypanosoma cruzi Residence in a LAMP-Deficient Intracellular Environment. Front Cell Infect Microbiol 2022; 11:788482. [PMID: 35071040 PMCID: PMC8770540 DOI: 10.3389/fcimb.2021.788482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 12/06/2021] [Indexed: 01/08/2023] Open
Abstract
Trypanosoma cruzi invades non-professional phagocytic cells by subverting their membrane repair process, which is dependent on membrane injury and cell signaling, intracellular calcium increase, and lysosome recruitment. Cells lacking lysosome-associated membrane proteins 1 and 2 (LAMP1 and LAMP2) are less permissive to parasite invasion but more prone to parasite intracellular multiplication. Several passages through a different intracellular environment can significantly change T. cruzi's gene expression profile. Here, we evaluated whether one single passage through LAMP-deficient (KO) or wild-type (WT) fibroblasts, thus different intracellular environments, could influence T. cruzi Y strain trypomastigotes' ability to invade L6 myoblasts and WT fibroblasts host cells. Parasites released from LAMP2 KO cells (TcY-L2-/-) showed higher invasion, calcium signaling, and membrane injury rates, for the assays in L6 myoblasts, when compared to those released from WT (TcY-WT) or LAMP1/2 KO cells (TcY-L1/2-/-). On the other hand, TcY-L1/2-/- showed higher invasion, calcium signaling, and cell membrane injury rates, for the assays in WT fibroblasts, compared to TcY-WT and TcY-L1/2-/-. Albeit TcY-WT presented an intermediary invasion and calcium signaling rates, compared to the others, in WT fibroblasts, they induced lower levels of injury, which reinforces that signals mediated by surface membrane protein interactions also have a significant contribution to trigger host cell calcium signals. These results clearly show that parasites released from WT or LAMP KO cells are distinct from each other. Additionally, these parasites' ability to invade the cell may be distinct depending on which cell type they interact with. Since these alterations most likely would reflect differences among parasite surface molecules, we also evaluated their proteome. We identified few protein complexes, membrane, and secreted proteins regulated in our dataset. Among those are some members of MASP, mucins, trans-sialidases, and gp63 proteins family, which are known to play an important role during parasite infection and could correlate to TcY-WT, TcY-L1/2-/-, and TcY-L2-/- biological behavior.
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Affiliation(s)
- Anny Carolline Silva Oliveira
- Department of Morphology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
- Protein Research Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Luisa Rezende
- Department of Morphology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Vladimir Gorshkov
- Protein Research Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Marcella Nunes Melo-Braga
- Department of Biochemistry and Immunology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Thiago Verano-Braga
- Hypertension Lab/Functional Proteomics Group, Department of Physiology and Biophysics, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Weslley Fernandes-Braga
- Department of Biochemistry and Immunology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Jorge Luís de Melo Guadalupe
- Department of Morphology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Gustavo Batista de Menezes
- Department of Morphology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Frank Kjeldsen
- Protein Research Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Hélida Monteiro de Andrade
- Laboratory of Leishmanioses, Department of Parasitology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Luciana de Oliveira Andrade
- Department of Morphology, Biological Sciences Institute—ICB, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
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4
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Yu X, Guo F, Mouneimne RB, Zhu G. Cryptosporidium parvum Elongation Factor 1α Participates in the Formation of Base Structure at the Infection Site During Invasion. J Infect Dis 2021; 221:1816-1825. [PMID: 31872225 DOI: 10.1093/infdis/jiz684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 12/21/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Cryptosporidium is a genus of apicomplexan parasites, the causative agents of cryptosporidiosis in humans and/or animals. Although most apicomplexans parasitize within the host cell cytosols, Cryptosporidium resides on top of host cells, but it is embraced by a double-layer parasitophorous vacuole membrane derived from host cell. There is an electron-dense band to separate the parasite from host cell cytoplasm, making it as an intracellular but extracytoplasmic parasite. However, little is known on the molecular machinery at the host cell-parasite interface. METHODS Cryptosporidium parvum at various developmental stages were obtained by infecting HCT-8 cells cultured in vitro. Immunofluorescence assay was used to detect CpEF1α with a polyclonal antibody and host cell F-actin with rhodamine-phalloidin. Recombinant CpEF1α protein was used to evaluate its effect on the invasion by the parasite. RESULTS We discovered that a C parvum translation elongation factor 1α (CpEF1α) was discharged from the invading sporozoites into host cells, forming a crescent-shaped patch that fully resembles the electron-dense band. At the same time, host cell F-actin aggregated to form a globular-shaped plug beneath the CpEF1α patch. The CpEF1α patch remained for most of the time but became weakened and dissolved upon the completion of the invasion process. In addition, recombinant CpEF1α protein could effectively interfere the invasion of sporozoites into host cells. CONCLUSIONS CpEF1α plays a role in the parasite invasion by participating in the formation of electron-dense band at the base of the parasite infection site.
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Affiliation(s)
- Xue Yu
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Fengguang Guo
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Rola Barhoumi Mouneimne
- Department of Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| | - Guan Zhu
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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5
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Gabagambi NP, Skorping A, Chacha M, Jonathan Kihedu K, Mennerat A. Life history shifts in an exploited African fish following invasion by a castrating parasite. Ecol Evol 2020; 10:13225-13235. [PMID: 33304532 PMCID: PMC7713912 DOI: 10.1002/ece3.6917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 01/19/2023] Open
Abstract
Evolutionary theory predicts that infection by a parasite that reduces future host survival or fecundity should select for increased investment in current reproduction. In this study, we use the cestode Ligula intestinalis and its intermediate fish host Engraulicypris sardella in Wissman Bay, Lake Nyasa (Tanzania), as a model system. Using data about infection of E. sardella fish hosts by L. intestinalis collected for a period of 10 years, we explored whether parasite infection affects the fecundity of the fish host E. sardella, and whether host reproductive investment has increased at the expense of somatic growth. We found that L. intestinalis had a strong negative effect on the fecundity of its intermediate fish host. For the noninfected fish, we observed an increase in relative gonadal weight at maturity over the study period, while size at maturity decreased. These findings suggest that the life history of E. sardella has been shifting toward earlier reproduction. Further studies are warranted to assess whether these changes reflect plastic or evolutionary responses. We also discuss the interaction between parasite and fishery-mediated selection as a possible explanation for the decline of E. sardella stock in the lake.
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Affiliation(s)
| | - Arne Skorping
- Department of Biological SciencesUniversity of BergenBergenNorway
| | - Mwita Chacha
- Department of Aquatic Sciences and Fisheries TechnologyCollege of Agricultural Sciences and Fisheries TechnologyUniversity of Dar es SalaamDar es SalaamTanzania
| | | | - Adele Mennerat
- Department of Biological SciencesUniversity of BergenBergenNorway
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6
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Kanjee U, Grüring C, Babar P, Meyers A, Dash R, Pereira L, Mascarenhas A, Chaand M, Rangel GW, Clark MA, Chery L, Gomes E, Rathod PK, Duraisingh MT. Plasmodium vivax Strains Use Alternative Pathways for Invasion. J Infect Dis 2020; 223:1817-1821. [PMID: 32941614 DOI: 10.1093/infdis/jiaa592] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/16/2020] [Indexed: 12/19/2022] Open
Abstract
Plasmodium vivax has 2 invasion ligand/host receptor pathways (P. vivax Duffy-binding protein/Duffy antigen receptor for chemokines [DARC] and P. vivax reticulocyte binding protein 2b/transferrin receptor [TfR1]) that are promising targets for therapeutic intervention. We optimized invasion assays with isogenic cultured reticulocytes. Using a receptor blockade approach with multiple P. vivax isolates, we found that all strains utilized both DARC and TfR1, but with significant variation in receptor usage. This suggests that P. vivax, like Plasmodium falciparum, uses alternative invasion pathways, with implications for pathogenesis and vaccine development.
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Affiliation(s)
- Usheer Kanjee
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Christof Grüring
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Prasad Babar
- University of Washington, Seattle, Washington, USA.,Department of Medicine, Goa Medical College Hospital, Bambolim, Goa, India
| | - Anosha Meyers
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Rashmi Dash
- University of Washington, Seattle, Washington, USA.,Department of Medicine, Goa Medical College Hospital, Bambolim, Goa, India
| | - Ligia Pereira
- University of Washington, Seattle, Washington, USA.,Department of Medicine, Goa Medical College Hospital, Bambolim, Goa, India
| | - Anjali Mascarenhas
- University of Washington, Seattle, Washington, USA.,Department of Medicine, Goa Medical College Hospital, Bambolim, Goa, India
| | - Mudit Chaand
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Gabriel W Rangel
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Martha A Clark
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Laura Chery
- University of Washington, Seattle, Washington, USA
| | - Edwin Gomes
- Department of Medicine, Goa Medical College Hospital, Bambolim, Goa, India
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Abstract
While vector-borne parasite transmission often operates via generalist-feeding vectors facilitating cross-species transmission in host communities, theory describing the relationship between host species diversity and parasite invasion in these systems is underdeveloped. Host community composition and abundance vary across space and time, generating opportunities for parasite invasion. To explore how host community variation can modify parasite invasion potential, we develop a model for vector-borne parasite transmission dynamics that includes a host community of arbitrary richness and species' abundance. To compare invasion potential across communities, we calculate the community basic reproductive ratio of the parasite. We compare communities comprising a set of host species to their subsets, which allows for flexible scenario building including the introduction of novel host species and species loss. We allow vector abundance to scale with, or be independent of, community size, capturing regulation by feeding opportunities and non-host effects such as limited oviposition sites. Motivated by equivocal data relating host species competency to abundance, we characterize plausible host communities via phenomenological relationships between host species abundance and competency. We identify an underappreciated mechanism whereby changes to communities simultaneously alter average competency and the vector to host ratio and demonstrate that the interaction can profoundly influence invasion potential.
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Affiliation(s)
- John E Vinson
- Odum School of Ecology, University of Georgia, 140 East Green Street, Athens, GA 30602, USA.,Center for the Ecology of Infectious Diseases, University of Georgia, 140 East Green Street, Athens, GA 30602, USA
| | - Andrew W Park
- Odum School of Ecology, University of Georgia, 140 East Green Street, Athens, GA 30602, USA.,Center for the Ecology of Infectious Diseases, University of Georgia, 140 East Green Street, Athens, GA 30602, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 140 East Green Street, Athens, GA 30602, USA
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8
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Kanjee U, Grüring C, Chaand M, Lin KM, Egan E, Manzo J, Jones PL, Yu T, Barker R Jr, Weekes MP, Duraisingh MT. CRISPR/Cas9 knockouts reveal genetic interaction between strain-transcendent erythrocyte determinants of Plasmodium falciparum invasion. Proc Natl Acad Sci U S A 2017; 114:E9356-65. [PMID: 29078358 DOI: 10.1073/pnas.1711310114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During malaria blood-stage infections, Plasmodium parasites interact with the RBC surface to enable invasion followed by intracellular proliferation. Critical factors involved in invasion have been identified using biochemical and genetic approaches including specific knockdowns of genes of interest from primary CD34+ hematopoietic stem cells (cRBCs). Here we report the development of a robust in vitro culture system to produce RBCs that allow the generation of gene knockouts via CRISPR/Cas9 using the immortal JK-1 erythroleukemia line. JK-1 cells spontaneously differentiate, generating cells at different stages of erythropoiesis, including terminally differentiated nucleated RBCs that we term "jkRBCs." A screen of small-molecule epigenetic regulators identified several bromodomain-specific inhibitors that promote differentiation and enable production of synchronous populations of jkRBCs. Global surface proteomic profiling revealed that jkRBCs express all known Pfalciparum host receptors in a similar fashion to cRBCs and that multiple Pfalciparum strains invade jkRBCs at comparable levels to cRBCs and RBCs. Using CRISPR/Cas9, we deleted two host factors, basigin (BSG) and CD44, for which no natural nulls exist. BSG interacts with the parasite ligand Rh5, a prominent vaccine candidate. A BSG knockout was completely refractory to parasite invasion in a strain-transcendent manner, confirming the essential role for BSG during invasion. CD44 was recently identified in an RNAi screen of blood group genes as a host factor for invasion, and we show that CD44 knockout results in strain-transcendent reduction in invasion. Furthermore, we demonstrate a functional interaction between these two determinants in mediating Pfalciparum erythrocyte invasion.
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Cancela M, Corvo I, DA Silva E, Teichmann A, Roche L, Díaz A, Tort JF, Ferreira HB, Zaha A. Functional characterization of single-domain cystatin-like cysteine proteinase inhibitors expressed by the trematode Fasciola hepatica. Parasitology 2017; 144:1695-707. [PMID: 28697819 DOI: 10.1017/S0031182017001093] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cystatins are small, phylogenetically conserved proteins that are tight-binding inhibitors of cysteine proteinases. The liver fluke Fasciola hepatica uses a diverse set of cysteine proteinases of the papain superfamily for host invasion, immune evasion and nutrition, but little is known about the regulation of these enzymes. The aim of this work is to characterize the cystatin repertoire of F. hepatica. For this purpose, we first surveyed the available sequence databases, identifying three different F. hepatica single-domain cystatins. In agreement with the in silico predictions, at least three small proteins with cysteine proteinase binding activity were identified. Phylogenetic analyses showed that the three cystatins (named FhStf-1, -2 and -3) are members of the I25A subfamily (stefins). Whereas FhStf-1 grouped with classical stefins, FhStf-2 and 3 fell in a divergent stefin subgroup unusually featuring signal peptides. Recombinant rFhStf-1, -2 and -3 had potent inhibitory activity against F. hepatica cathepsin L cysteine proteinases but differed in their capacity to inhibit mammalian cathepsin B, L and C. FhStf-1 was localized in the F. hepatica reproductive organs (testes and ovary), and at the surface lamella of the adult gut, where it may regulate cysteine proteinases related with reproduction and digestion, respectively. FhStf-1 was also detected among F. hepatica excretion-secretion (E/S) products of adult flukes. This suggests that it is secreted by non-classical secretory pathway and that it may interact with host lysosomal cysteine proteinases.
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10
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Yu X, Zhang H, Zhu G. Characterization of Host Cell Mutants Significantly Resistant to Cryptosporidium parvum Infection. J Eukaryot Microbiol 2017; 64:843-849. [PMID: 28432811 DOI: 10.1111/jeu.12419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/15/2017] [Accepted: 04/17/2017] [Indexed: 11/30/2022]
Abstract
Cryptosporidium parvum is a parasitic protist and a causative agent of mild-to-severe diarrheal diseases in humans and animals. Despite its globally recognized importance, knowledge on the mechanism of parasite invasion and molecular interactions between host cells and the parasite is limited. Here, we report the establishment of 43 mutant cell lines derived from HCT-8 cells by UV-induced mutagenesis and the characterization of three mutants with significantly reduced susceptibility to cryptosporidial infection. Based on qRT-PCR assay performed at 18 h postinfection time, the parasite loads could be reduced by ~45%, ~35%, and ~20% in mutants A05, B08, and B12, respectively (p < 0.001 in all three mutants vs. HCT-8 cells). The mutagenesis mainly affected the attachment of parasite in A05 (i.e. ~30% reduction, p < 0.001 vs. HCT-8), and intracellular development in B08 and B12. The three cell mutants may serve as valuable reagents to further investigate the mechanism of parasite invasion and intracellular development by identifying the gene mutations associated with the parasite attachment (A05) and intracellular development (B08 and B12).
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Affiliation(s)
- Xue Yu
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 4467 TAMU, College Station, Texas, USA
| | - Haili Zhang
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 4467 TAMU, College Station, Texas, USA
| | - Guan Zhu
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 4467 TAMU, College Station, Texas, USA
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Gruszczyk J, Lim NT, Arnott A, He WQ, Nguitragool W, Roobsoong W, Mok YF, Murphy JM, Smith KR, Lee S, Bahlo M, Mueller I, Barry AE, Tham WH. Structurally conserved erythrocyte-binding domain in Plasmodium provides a versatile scaffold for alternate receptor engagement. Proc Natl Acad Sci U S A 2016; 113:E191-200. [PMID: 26715754 DOI: 10.1073/pnas.1516512113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Understanding how malaria parasites gain entry into human red blood cells is essential for developing strategies to stop blood stage infection. Plasmodium vivax preferentially invades reticulocytes, which are immature red blood cells. The organism has two erythrocyte-binding protein families: namely, the Duffy-binding protein (PvDBP) and the reticulocyte-binding protein (PvRBP) families. Several members of the PvRBP family bind reticulocytes, specifically suggesting a role in mediating host cell selectivity of P. vivax. Here, we present, to our knowledge, the first high-resolution crystal structure of an erythrocyte-binding domain from PvRBP2a, solved at 2.12 Å resolution. The monomeric molecule consists of 10 α-helices and one short β-hairpin, and, although the structural fold is similar to that of PfRh5--the essential invasion ligand in Plasmodium falciparum--its surface properties are distinct and provide a possible mechanism for recognition of alternate receptors. Sequence alignments of the crystallized fragment of PvRBP2a with other PvRBPs highlight the conserved placement of disulfide bonds. PvRBP2a binds mature red blood cells through recognition of an erythrocyte receptor that is neuraminidase- and chymotrypsin-resistant but trypsin-sensitive. By examining the patterns of sequence diversity within field isolates, we have identified and mapped polymorphic residues to the PvRBP2a structure. Using mutagenesis, we have also defined the critical residues required for erythrocyte binding. Characterization of the structural features that govern functional erythrocyte binding for the PvRBP family provides a framework for generating new tools that block P. vivax blood stage infection.
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