1
|
Zargar UR, Introini V, Assolini JP, Paoletta M. Editorial: Reviews in parasite & host. Front Cell Infect Microbiol 2024; 14:1391289. [PMID: 38638829 PMCID: PMC11023821 DOI: 10.3389/fcimb.2024.1391289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 03/19/2024] [Indexed: 04/20/2024] Open
Affiliation(s)
- Ummer R. Zargar
- Department of Zoology, Govt Degree College (GDC) Dooru, Jammu and Kashmir, Anantnag, India
- Department of Higher Education, Jammu and Kashmir, Anantnag, India
| | - Viola Introini
- Department of Higher Education, Jammu and Kashmir, Anantnag, India
| | | | - Martina Paoletta
- Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina
| |
Collapse
|
2
|
Jmel MA, Voet H, Araújo RN, Tirloni L, Sá-Nunes A, Kotsyfakis M. Tick Salivary Kunitz-Type Inhibitors: Targeting Host Hemostasis and Immunity to Mediate Successful Blood Feeding. Int J Mol Sci 2023; 24. [PMID: 36675071 DOI: 10.3390/ijms24021556] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 01/15/2023] Open
Abstract
Kunitz domain-containing proteins are ubiquitous serine protease inhibitors with promising therapeutic potential. They target key proteases involved in major cellular processes such as inflammation or hemostasis through competitive inhibition in a substrate-like manner. Protease inhibitors from the Kunitz superfamily have a low molecular weight (18-24 kDa) and are characterized by the presence of one or more Kunitz motifs consisting of α-helices and antiparallel β-sheets stabilized by three disulfide bonds. Kunitz-type inhibitors are an important fraction of the protease inhibitors found in tick saliva. Their roles in inhibiting and/or suppressing host homeostatic responses continue to be shown to be additive or synergistic with other protease inhibitors such as cystatins or serpins, ultimately mediating successful blood feeding for the tick. In this review, we discuss the biochemical features of tick salivary Kunitz-type protease inhibitors. We focus on their various effects on host hemostasis and immunity at the molecular and cellular level and their potential therapeutic applications. In doing so, we highlight that their pharmacological properties can be exploited for the development of novel therapies and vaccines.
Collapse
|
3
|
Faso C, Hehl AB. Editorial: The Cell Biology of Protist Parasite-Host Interfaces. Front Cell Dev Biol 2022; 10:866421. [PMID: 35273965 PMCID: PMC8902235 DOI: 10.3389/fcell.2022.866421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Carmen Faso
- Institute of Cell Biology and Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Adrian B Hehl
- Institute of Parasitology, University of Zürich, Zürich, Switzerland
| |
Collapse
|
4
|
Burgert L, Zaloumis S, Dini S, Marquart L, Cao P, Cherkaoui M, Gobeau N, McCarthy J, Simpson JA, Möhrle JJ, Penny MA. Parasite-Host Dynamics throughout Antimalarial Drug Development Stages Complicate the Translation of Parasite Clearance. Antimicrob Agents Chemother 2021; 65:e01539-20. [PMID: 33526486 DOI: 10.1128/AAC.01539-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 01/20/2021] [Indexed: 11/21/2022] Open
Abstract
Ensuring continued success against malaria depends on a pipeline of new antimalarials. Antimalarial drug development utilizes preclinical murine and experimental human malaria infection studies to evaluate drug efficacy. Ensuring continued success against malaria depends on a pipeline of new antimalarials. Antimalarial drug development utilizes preclinical murine and experimental human malaria infection studies to evaluate drug efficacy. A sequential approach is typically adapted, with results from each stage informing the design of the next stage of development. The validity of this approach depends on confidence that results from murine malarial studies predict the outcome of clinical trials in humans. Parasite clearance rates following treatment are key parameters of drug efficacy. To investigate the validity of forward predictions, we developed a suite of mathematical models to capture parasite growth and drug clearance along the drug development pathway and estimated parasite clearance rates. When comparing the three infection experiments, we identified different relationships of parasite clearance with dose and different maximum parasite clearance rates. In Plasmodium berghei-NMRI mouse infections, we estimated a maximum parasite clearance rate of 0.2 (1/h); in Plasmodium falciparum-SCID mouse infections, 0.05 (1/h); and in human volunteer infection studies with P. falciparum, we found a maximum parasite clearance rate of 0.12 (1/h) and 0.18 (1/h) after treatment with OZ439 and MMV048, respectively. Sensitivity analysis revealed that host-parasite driven processes account for up to 25% of variance in parasite clearance for medium-high doses of antimalarials. Although there are limitations in translating parasite clearance rates across these experiments, they provide insight into characterizing key parameters of drug action and dose response and assist in decision-making regarding dosage for further drug development.
Collapse
|
5
|
Pasini EM, Kocken CHM. Parasite-Host Interaction and Pathophysiology Studies of the Human Relapsing Malarias Plasmodium vivax and Plasmodium ovale Infections in Non-Human Primates. Front Cell Infect Microbiol 2021; 10:614122. [PMID: 33680982 PMCID: PMC7925837 DOI: 10.3389/fcimb.2020.614122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/24/2020] [Indexed: 12/26/2022] Open
Abstract
Malaria remains a serious health concern across the globe. Historically neglected, non-Falciparum human malarias were put back on the agenda by a paradigm shift in the fight against malaria from malaria control to malaria eradication. Here, we review the modeling of the relapsing parasites Plasmodium vivax (P. vivax) and Plasmodium ovale (P. ovale) in non-human primates with a specific focus on the contribution of these models to our current understanding of the factors that govern parasite-host interactions in P. vivax and P. ovale parasite biology and pathophysiology.
Collapse
Affiliation(s)
- Erica M Pasini
- Department of Parasitology, Biomedical Primate Research Center, Rijswijk, Netherlands
| | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Center, Rijswijk, Netherlands
| |
Collapse
|
6
|
Jamie GA, Van Belleghem SM, Hogan BG, Hamama S, Moya C, Troscianko J, Stoddard MC, Kilner RM, Spottiswoode CN. Multimodal mimicry of hosts in a radiation of parasitic finches. Evolution 2020; 74:2526-2538. [PMID: 32696463 DOI: 10.1111/evo.14057] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 12/08/2019] [Revised: 06/27/2020] [Accepted: 07/02/2020] [Indexed: 01/16/2023]
Abstract
Brood parasites use the parental care of others to raise their young and sometimes employ mimicry to dupe their hosts. The brood-parasitic finches of the genus Vidua are a textbook example of the role of imprinting in sympatric speciation. Sympatric speciation is thought to occur in Vidua because their mating traits and host preferences are strongly influenced by their early host environment. However, this alone may not be sufficient to isolate parasite lineages, and divergent ecological adaptations may also be required to prevent hybridization collapsing incipient species. Using pattern recognition software and classification models, we provide quantitative evidence that Vidua exhibit specialist mimicry of their grassfinch hosts, matching the patterns, colors and sounds of their respective host's nestlings. We also provide qualitative evidence of mimicry in postural components of Vidua begging. Quantitative comparisons reveal small discrepancies between parasite and host phenotypes, with parasites sometimes exaggerating their host's traits. Our results support the hypothesis that behavioral imprinting on hosts has not only enabled the origin of new Vidua species, but also set the stage for the evolution of host-specific, ecological adaptations.
Collapse
Affiliation(s)
- Gabriel A Jamie
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Steven M Van Belleghem
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Department of Biology, University of Puerto Rico-Rio Piedras, San Juan, Puerto Rico
| | - Benedict G Hogan
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey
| | | | | | - Jolyon Troscianko
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Mary Caswell Stoddard
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey
| | - Rebecca M Kilner
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Claire N Spottiswoode
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, Cape Town, South Africa
| |
Collapse
|
7
|
Mariën J, Borremans B, Verhaeren C, Kirkpatrick L, Gryseels S, Goüy de Bellocq J, Günther S, Sabuni CA, Massawe AW, Reijniers J, Leirs H. Density dependence and persistence of Morogoro arenavirus transmission in a fluctuating population of its reservoir host. J Anim Ecol 2019; 89:506-518. [PMID: 31545505 DOI: 10.1111/1365-2656.13107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 06/21/2019] [Accepted: 07/21/2019] [Indexed: 11/28/2022]
Abstract
A key aim in wildlife disease ecology is to understand how host and parasite characteristics influence parasite transmission and persistence. Variation in host population density can have strong impacts on transmission and outbreaks, and theory predicts particular transmission-density patterns depending on how parasites are transmitted between individuals. Here, we present the results of a study on the dynamics of Morogoro arenavirus in a population of multimammate mice (Mastomys natalensis). This widespread African rodent, which is also the reservoir host of Lassa arenavirus in West Africa, is known for its strong seasonal density fluctuations driven by food availability. We investigated to what degree virus transmission changes with host population density and how the virus might be able to persist during periods of low host density. A seven-year capture-mark-recapture study was conducted in Tanzania where rodents were trapped monthly and screened for the presence of antibodies against Morogoro virus. Observed seasonal seroprevalence patterns were compared with those generated by mathematical transmission models to test different hypotheses regarding the degree of density dependence and the role of chronically infected individuals. We observed that Morogoro virus seroprevalence correlates positively with host density with a lag of 1-4 months. Model results suggest that the observed seasonal seroprevalence dynamics can be best explained by a combination of vertical and horizontal transmission and that a small number of animals need to be infected chronically to ensure viral persistence. Transmission dynamics and viral persistence were best explained by the existence of both acutely and chronically infected individuals and by seasonally changing transmission rates. Due to the presence of chronically infected rodents, rodent control is unlikely to be a feasible approach for eliminating arenaviruses such as Lassa virus from Mastomys populations.
Collapse
Affiliation(s)
- Joachim Mariën
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium
| | - Benny Borremans
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium.,Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, LA, USA.,Interuniversity Institute for Biostatistics and Statistical Bioinformatics (I-BIOSTAT), Hasselt University, Hasselt, Belgium
| | | | | | - Sophie Gryseels
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium.,Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.,Clinical and Epidemiological Virology, Rega Institute, KU Leuven, Leuven, Belgium
| | - Joëlle Goüy de Bellocq
- Institute of Vertebrate Biology, Research Facility Studenec, The Czech Academy of Sciences, Brno, Czech Republic
| | - Stephan Günther
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | | | - Apia W Massawe
- PestManagement Centre, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Jonas Reijniers
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium.,Department of Engineering Management, University of Antwerp, Antwerp, Belgium
| | - Herwig Leirs
- Evolutionary Ecology Group, University of Antwerp, Antwerp, Belgium
| |
Collapse
|
8
|
Yap XZ, Lundie RJ, Feng G, Pooley J, Beeson JG, O'Keeffe M. Different Life Cycle Stages of Plasmodium falciparum Induce Contrasting Responses in Dendritic Cells. Front Immunol 2019; 10:32. [PMID: 30766530 PMCID: PMC6365426 DOI: 10.3389/fimmu.2019.00032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 10/22/2018] [Accepted: 01/08/2019] [Indexed: 12/02/2022] Open
Abstract
Dendritic cells are key linkers of innate and adaptive immunity. Efficient dendritic cell activation is central to the acquisition of immunity and the efficacy of vaccines. Understanding how dendritic cells are affected by Plasmodium falciparum blood-stage parasites will help to understand how immunity is acquired and maintained, and how vaccine responses may be impacted by malaria infection or exposure. This study investigates the response of dendritic cells to two different life stages of the malaria parasite, parasitized red blood cells and merozoites, using a murine model. We demonstrate that the dendritic cell responses to merozoites are robust whereas dendritic cell activation, particularly CD40 and pro-inflammatory cytokine expression, is compromised in the presence of freshly isolated parasitized red blood cells. The mechanism of dendritic cell suppression by parasitized red blood cells is host red cell membrane-independent. Furthermore, we show that cryopreserved parasitized red blood cells have a substantially reduced capacity for dendritic cell activation.
Collapse
Affiliation(s)
- Xi Zen Yap
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Rachel J Lundie
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Gaoqian Feng
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Joanne Pooley
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia.,Department of Microbiology, Monash University, Clayton, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Meredith O'Keeffe
- Burnet Institute, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| |
Collapse
|
9
|
Scholz B, Küpper FC, Vyverman W, Ólafsson HG, Karsten U. Chytridiomycosis of Marine Diatoms-The Role of Stress Physiology and Resistance in Parasite-Host Recognition and Accumulation of Defense Molecules. Mar Drugs 2017; 15:E26. [PMID: 28125065 PMCID: PMC5334607 DOI: 10.3390/md15020026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/07/2017] [Accepted: 01/13/2017] [Indexed: 02/05/2023] Open
Abstract
Little is known about the role of chemotaxis in the location and attachment of chytrid zoospores to potential diatom hosts. Hypothesizing that environmental stress parameters affect parasite-host recognition, four chytrid-diatom tandem cultures (Chytridium sp./Navicula sp., Rhizophydium type I/Nitzschia sp., Rhizophydium type IIa/Rhizosolenia sp., Rhizophydium type IIb/Chaetoceros sp.) were used to test the chemotaxis of chytrid zoospores and the presence of potential defense molecules in a non-contact-co-culturing approach. As potential triggers in the chemotaxis experiments, standards of eight carbohydrates, six amino acids, five fatty acids, and three compounds known as compatible solutes were used in individual and mixed solutions, respectively. In all tested cases, the whole-cell extracts of the light-stressed (continuous light exposure combined with 6 h UV radiation) hosts attracted the highest numbers of zoospores (86%), followed by the combined carbohydrate standard solution (76%), while all other compounds acted as weak triggers only. The results of the phytochemical screening, using biomass and supernatant extracts of susceptible and resistant host-diatom cultures, indicated in most of the tested extracts the presence of polyunsaturated fatty acids, phenols, and aldehydes, whereas the bioactivity screenings showed that the zoospores of the chytrid parasites were only significantly affected by the ethanolic supernatant extract of the resistant hosts.
Collapse
Affiliation(s)
- Bettina Scholz
- BioPol ehf., Einbúastig 2, 545 Skagaströnd, Iceland.
- Faculty of Natural Resource Sciences, University of Akureyri, Borgir v. Nordurslod, IS 600 Akureyri, Iceland.
| | - Frithjof C Küpper
- Oceanlab, University of Aberdeen, Main Street, Newburgh AB41 6AA, Scotland, UK.
| | - Wim Vyverman
- Department of Biology, Section of Protistology and Aquatic Ecology, University of Ghent, Krijgslaan 281 S8, 9000 Ghent, Belgium.
| | | | - Ulf Karsten
- Institute of Biological Sciences, Applied Ecology & Phycology, University of Rostock, Albert-Einstein-Strasse 3, 18059 Rostock, Germany.
| |
Collapse
|
10
|
de Bekker C, Ohm RA, Loreto RG, Sebastian A, Albert I, Merrow M, Brachmann A, Hughes DP. Gene expression during zombie ant biting behavior reflects the complexity underlying fungal parasitic behavioral manipulation. BMC Genomics 2015; 16:620. [PMID: 26285697 PMCID: PMC4545319 DOI: 10.1186/s12864-015-1812-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/03/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Adaptive manipulation of animal behavior by parasites functions to increase parasite transmission through changes in host behavior. These changes can range from slight alterations in existing behaviors of the host to the establishment of wholly novel behaviors. The biting behavior observed in Carpenter ants infected by the specialized fungus Ophiocordyceps unilateralis s.l. is an example of the latter. Though parasitic manipulation of host behavior is generally assumed to be due to the parasite's gene expression, few studies have set out to test this. RESULTS We experimentally infected Carpenter ants to collect tissue from both parasite and host during the time period when manipulated biting behavior is experienced. Upon observation of synchronized biting, samples were collected and subjected to mixed RNA-Seq analysis. We also sequenced and annotated the O. unilateralis s.l. genome as a reference for the fungal sequencing reads. CONCLUSIONS Our mixed transcriptomics approach, together with a comparative genomics study, shows that the majority of the fungal genes that are up-regulated during manipulated biting behavior are unique to the O. unilateralis s.l. genome. This study furthermore reveals that the fungal parasite might be regulating immune- and neuronal stress responses in the host during manipulated biting, as well as impairing its chemosensory communication and causing apoptosis. Moreover, we found genes up-regulated during manipulation that putatively encode for proteins with reported effects on behavioral outputs, proteins involved in various neuropathologies and proteins involved in the biosynthesis of secondary metabolites such as alkaloids.
Collapse
Affiliation(s)
- Charissa de Bekker
- Institute of Medical Psychology, Faculty of Medicine, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336, Munich, Germany.
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA.
| | - Robin A Ohm
- Microbiology, Faculty of Science, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Raquel G Loreto
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
- CAPES Foundation, Ministry of Education of Brazil, Brasília, 70040-020, DF, Brazil
| | - Aswathy Sebastian
- Bioinformatics Consulting Center, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
| | - Istvan Albert
- Bioinformatics Consulting Center, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
- Department of Biochemistry and Molecular Biology, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
| | - Martha Merrow
- Institute of Medical Psychology, Faculty of Medicine, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336, Munich, Germany
| | - Andreas Brachmann
- Faculty of Biology, Section Genetics, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Martinsried, Germany
| | - David P Hughes
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA.
| |
Collapse
|
11
|
Leow CY, Willis C, Osman A, Mason L, Simon A, Smith BJ, Gasser RB, Jones MK, Hofmann A. Crystal structure and immunological properties of the first annexin from Schistosoma mansoni: insights into the structural integrity of the schistosomal tegument. FEBS J 2014; 281:1209-25. [PMID: 24428567 DOI: 10.1111/febs.12700] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [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: 10/01/2013] [Revised: 12/12/2013] [Accepted: 12/19/2013] [Indexed: 11/28/2022]
Abstract
Schistosomiasis is a major parasitic disease of humans, second only to malaria in its global impact. The disease is caused by digenean trematodes that infest the vasculature of their human hosts. These flukes are limited externally by a body wall composed of a syncytial epithelium, the apical surface membrane of which is a parasitism-adapted dual membrane complex. Annexins are thought to be of integral importance for the stability of this apical membrane system. Here, we present the first structural and immunobiochemical characterization of an annexin from Schistosoma mansoni. The crystal structure of annexin B22 confirms the presence of the previously predicted α-helical segment in the II/III linker and reveals a covalently linked head-to-head dimer. From the calcium-bound crystal structure of this protein, canonical type II, type III and B site positions are occupied, and a novel binding site has been identified. The dimer arrangement observed in the crystal structure suggests the presence of two prominent features, a potential non-canonical membrane binding site and a potential binding groove opposite to the former. Results from transcriptional profiling during development show that annexin B22 expression is correlated with life stages of the parasite that possess the syncytial tegument layer, and ultrastructural localization by immuno-electron microscopy confirms the occurrence of annexins in the tegument of S. mansoni. Data from membrane binding and aggregation assays indicate the presence of differential molecular mechanisms and support the hypothesis of annexin B22 providing structural integrity in the tegument.
Collapse
Affiliation(s)
- Chiuan Yee Leow
- School of Veterinary Science, University of Queensland, Gatton, Australia; Queensland Institute of Medical Research, Herston, Australia; Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang, Malaysia
| | | | | | | | | | | | | | | | | |
Collapse
|