1
|
Anaguano D, Adewale-Fasoro O, Vick GS, Yanik S, Blauwkamp J, Fierro MA, Absalon S, Srinivasan P, Muralidharan V. Plasmodium RON11 triggers biogenesis of the merozoite rhoptry pair and is essential for erythrocyte invasion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.29.577654. [PMID: 38352500 PMCID: PMC10862748 DOI: 10.1101/2024.01.29.577654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Malaria is a global and deadly human disease caused by the apicomplexan parasites of the genus Plasmodium. Parasite proliferation within human red blood cells (RBC) is associated with the clinical manifestations of the disease. This asexual expansion within human RBCs, begins with the invasion of RBCs by P. falciparum, which is mediated by the secretion of effectors from two specialized club-shaped secretory organelles in merozoite-stage parasites known as rhoptries. We investigated the function of the Rhoptry Neck Protein 11 (RON11), which contains seven transmembrane domains and calcium-binding EF-hand domains. We generated conditional mutants of the P. falciparum RON11. Knockdown of RON11 inhibits parasite growth by preventing merozoite invasion. The loss of RON11 did not lead to any defects in processing of rhoptry proteins but instead led to a decrease in the amount of rhoptry proteins. We utilized ultrastructure expansion microscopy (U-ExM) to determine the effect of RON11 knockdown on rhoptry biogenesis. Surprisingly, in the absence of RON11, fully developed merozoites had only one rhoptry each. The single rhoptry in RON11 deficient merozoites were morphologically typical with a bulb and a neck oriented into the apical polar ring. Moreover, rhoptry proteins are trafficked accurately to the single rhoptry in RON11 deficient parasites. These data show that in the absence of RON11, the first rhoptry is generated during schizogony but upon the start of cytokinesis, the second rhoptry never forms. Interestingly, these single-rhoptry merozoites were able to attach to host RBCs but are unable to invade RBCs. Instead, RON11 deficient merozoites continue to engage with RBC for prolonged periods eventually resulting in echinocytosis, a result of secreting the contents from the single rhoptry into the RBC. Together, our data show that RON11 triggers the de novo biogenesis of the second rhoptry and functions in RBC invasion.
Collapse
Affiliation(s)
- David Anaguano
- Department of Cellular Biology, University of Georgia, Athens, GA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA
| | - Opeoluwa Adewale-Fasoro
- Department of Molecular Microbiology and Immunology, and Johns Hopkins Malaria Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - Grace S. Vick
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Sean Yanik
- Department of Molecular Microbiology and Immunology, and Johns Hopkins Malaria Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - James Blauwkamp
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Manuel A. Fierro
- Department of Cellular Biology, University of Georgia, Athens, GA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA
| | - Sabrina Absalon
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN
| | - Prakash Srinivasan
- Department of Molecular Microbiology and Immunology, and Johns Hopkins Malaria Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - Vasant Muralidharan
- Department of Cellular Biology, University of Georgia, Athens, GA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA
| |
Collapse
|
2
|
Andrews M, Baum J, Gilson PR, Wilson DW. Bottoms up! Malaria parasite invasion the right way around. Trends Parasitol 2023; 39:1004-1013. [PMID: 37827961 DOI: 10.1016/j.pt.2023.09.010] [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: 07/22/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023]
Abstract
A critical part of the malaria parasite's life cycle is invasion of red blood cells (RBCs) by merozoites. Inside RBCs, the parasite forms a schizont, which undergoes segmentation to produce daughter merozoites. These cells are released, establishing cycles of invasion. Traditionally, merozoites are represented as nonmotile, egg-shaped cells that invade RBCs 'narrower end' first and pack within schizonts with this narrower end facing outwards. Here, we discuss recent evidence and re-evaluate previous data which suggest that merozoites are capable of motility and have spherical or elongated-teardrop shapes. Furthermore, merozoites invade RBCs 'wider end' first and pack within schizonts with this wider end facing outwards. We encourage the field to review this revised model and consider its implications for future studies.
Collapse
Affiliation(s)
- Mia Andrews
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Jake Baum
- School of Biomedical Sciences, UNSW Sydney, Kensington, NSW 2052, Australia; Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Paul R Gilson
- Burnet Institute, Melbourne 3004, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne, Melbourne 3010, Victoria, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia; Burnet Institute, Melbourne 3004, Victoria, Australia; Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, 5005, SA, Australia.
| |
Collapse
|
3
|
Ito D, Kondo Y, Takashima E, Iriko H, Thongkukiatkul A, Torii M, Otsuki H. Roles of the RON3 C-terminal fragment in erythrocyte invasion and blood-stage parasite proliferation in Plasmodium falciparum. Front Cell Infect Microbiol 2023; 13:1197126. [PMID: 37457963 PMCID: PMC10340547 DOI: 10.3389/fcimb.2023.1197126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/15/2023] [Indexed: 07/18/2023] Open
Abstract
Plasmodium species cause malaria, and in the instance of Plasmodium falciparum is responsible for a societal burden of over 600,000 deaths annually. The symptoms and pathology of malaria are due to intraerythocytic parasites. Erythrocyte invasion is mediated by the parasite merozoite stage, and is accompanied by the formation of a parasitophorous vacuolar membrane (PVM), within which the parasite develops. The merozoite apical rhoptry organelle contains various proteins that contribute to erythrocyte attachment and invasion. RON3, a rhoptry bulb membrane protein, undergoes protein processing and is discharged into the PVM during invasion. RON3-deficient parasites fail to develop beyond the intraerythrocytic ring stage, and protein export into erythrocytes by the Plasmodium translocon of exported proteins (PTEX) apparatus is abrogated, as well as glucose uptake into parasites. It is known that truncated N- and C-terminal RON3 fragments are present in rhoptries, but it is unclear which RON3 fragments contribute to protein export by PTEX and glucose uptake through the PVM. To investigate and distinguish the roles of the RON3 C-terminal fragment at distinct developmental stages, we used a C-terminus tag for conditional and post-translational control. We demonstrated that RON3 is essential for blood-stage parasite survival, and knockdown of RON3 C-terminal fragment expression from the early schizont stage induces a defect in erythrocyte invasion and the subsequent development of ring stage parasites. Protein processing of full-length RON3 was partially inhibited in the schizont stage, and the RON3 C-terminal fragment was abolished in subsequent ring-stage parasites compared to the RON3 N-terminal fragment. Protein export and glucose uptake were abrogated specifically in the late ring stage. Plasmodial surface anion channel (PSAC) activity was partially retained, facilitating small molecule traffic across the erythrocyte membrane. The knockdown of the RON3 C-terminal fragment after erythrocyte invasion did not alter parasite growth. These data suggest that the RON3 C-terminal fragment participates in erythrocyte invasion and serves an essential role in the progression of ring-stage parasite growth by the establishment of the nutrient-permeable channel in the PVM, accompanying the transport of ring-stage parasite protein from the plasma membrane to the PVM.
Collapse
Affiliation(s)
- Daisuke Ito
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yoko Kondo
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hideyuki Iriko
- Division of Global Infectious Diseases, Department of Public Health, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | | | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| |
Collapse
|
4
|
Ge J, Wang Q, Chen G, Kassegne K, Zhang H, Yu J, Tang J, Wang B, Lu F, Cao J, Han ET, Cheng Y. Immunogenicity and antigenicity of a conserved fragment of the rhoptry-associated membrane antigen of Plasmodium vivax. Parasit Vectors 2022; 15:428. [PMID: 36380374 PMCID: PMC9664424 DOI: 10.1186/s13071-022-05561-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Background Plasmodium vivax rhoptry-associated membrane antigen (RAMA) is a glycophosphatidylinositol-anchored membrane protein currently under consideration as a malaria vaccine candidate. Immunoglobulin G (IgG) antibodies induced by P. vivax RAMA (PvRAMA) have been proved to persist over 12 months in the sera of people infected with P. vivax. It has also been shown that through stimulation of peripheral blood mononuclear cells with PvRAMA in vitro, the antigen can induce CD4+ T cells to produce interleukin-10. However, the genetic diversity of the RAMA gene in isolates of P. vivax (pvrama) and the immunogenicity of PvRAMA in animals remain unclear. Methods Genomic DNA was extracted from blood samples (n = 25) of patients in Jiangsu Province, China with imported infections of P. vivax from endemic countries in South and Southeast Asia. The extract genomic DNA was used as templates to amplify the P. vivax rama gene (pvrama) by PCR, and the PCR products were then sequenced and analyzed by the DnaSP, MEGA, and GeneDoc software packages. Recombinant PvRAMA (rPvRAMA) protein was expressed and purified, and then used to immunize mice. Levels of total IgG and different IgG subclasses of rPvRAMA-immunized mice were evaluated by enzyme-linked immunosorbent assay. Also, spleen cells of rPvRAMA-immunized mice were stimulated with rPvRAMA in vitro and levels of T cells were measured by flow cytometry. Results The average pairwise nucleotide diversity (π) of the pvrama gene was 0.00190, and the haplotype diversity (Hd) was 0.982. The C-terminal of PvRAMA showed lower haplotype diversity compared to the N-terminal and was completely conserved at amino acid sites related to erythrocyte binding. To further characterize immunogenicity of the C-terminal of PvRAMA, mice were immunized with rPvRAMA antigen. The rPvRAMA protein induced antibody responses, with the end-point titer ranging from 1:10,000 to 1:5,120,000. IgG1 was the predominant IgG subclass in rPvRAMA-immunized mice, followed by IgG2b. In addition, levels of CD4+ and CD8+ T cells in the rPvRAMA-stimulated group were significantly higher than those in the phosphate-buffered saline-stimulated group (normal control group). Conclusions The high conservation at specific amino acid sites and the high immunogenicity of the C-terminal of PvRAMA indicate the presence of conserved epitopes able to generate broadly reactive humoral and cellular immune responses. These findings support the potential of PvRAMA to serve as a vaccine candidate against P. vivax infection. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05561-8.
Collapse
|
5
|
Martinez M, Chen WD, Cova MM, Molnár P, Mageswaran SK, Guérin A, John ARO, Lebrun M, Chang YW. Rhoptry secretion system structure and priming in Plasmodium falciparum revealed using in situ cryo-electron tomography. Nat Microbiol 2022; 7:1230-1238. [PMID: 35817892 PMCID: PMC7613239 DOI: 10.1038/s41564-022-01171-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/07/2022] [Indexed: 01/13/2023]
Abstract
Apicomplexan parasites secrete contents of the rhoptries, club-shaped organelles in the apical region, into host cells to permit their invasion and establishment of infection. The rhoptry secretory apparatus (RSA), which is critical for rhoptry secretion, was recently discovered in Toxoplasma and Cryptosporidium. It is unknown whether a similar molecular machinery exists in the malaria parasite Plasmodium. In this study, we use in situ cryo-electron tomography to investigate the rhoptry secretion system in P. falciparum merozoites. We identify the presence of an RSA at the cell apex and a morphologically distinct apical vesicle docking the tips of the two rhoptries to the RSA. We also discover two additional rhoptry organizations that lack the apical vesicle. Using subtomogram averaging, we reveal different conformations of the RSA structure corresponding to different rhoptry organizations. Our results highlight previously unknown steps in the process of rhoptry secretion and indicate a regulatory role for the conserved apical vesicle in host invasion by apicomplexan parasites.
Collapse
Affiliation(s)
- Matthew Martinez
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William David Chen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Petra Molnár
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Audrey R Odom John
- Department of Pediatrics, Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Maryse Lebrun
- LPHI, UMR 5235 CNRS, Université de Montpellier, Montpellier, France
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
6
|
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: 17] [Impact Index Per Article: 8.5] [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
|
7
|
Basis for drug selectivity of plasmepsin IX and X inhibition in Plasmodium falciparum and vivax. Structure 2022; 30:947-961.e6. [PMID: 35460613 DOI: 10.1016/j.str.2022.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/02/2022] [Accepted: 03/29/2022] [Indexed: 11/20/2022]
Abstract
Plasmepsins IX (PMIX) and X (PMX) are essential aspartyl proteases for Plasmodium spp. egress, invasion, and development. WM4 and WM382 inhibit PMIX and PMX in Plasmodium falciparum and P. vivax. WM4 inhibits PMX, while WM382 is a dual inhibitor of PMIX and PMX. To understand their function, we identified protein substrates. Enzyme kinetic and structural analyses identified interactions responsible for drug specificity. PMIX and PMX have similar substrate specificity; however, there are distinct differences for peptide and protein substrates. Differences in WM4 and WM382 binding for PMIX and PMX map to variations in the S' region and engagement of the active site S3 pocket. Structures of PMX reveal interactions and mechanistic detail of drug binding important for development of clinical candidates against these targets.
Collapse
|
8
|
Pasternak M, Verhoef JMJ, Wong W, Triglia T, Mlodzianoski MJ, Geoghegan N, Evelyn C, Wardak AZ, Rogers K, Cowman AF. RhopH2 and RhopH3 export enables assembly of the RhopH complex on P. falciparum-infected erythrocyte membranes. Commun Biol 2022; 5:333. [PMID: 35393572 PMCID: PMC8989874 DOI: 10.1038/s42003-022-03290-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 03/17/2022] [Indexed: 11/09/2022] Open
Abstract
RhopH complexes consists of Clag3, RhopH2 and RhopH3 and are essential for growth of Plasmodium falciparum inside infected erythrocytes. Proteins are released from rhoptry organelles during merozoite invasion and trafficked to the surface of infected erythrocytes and enable uptake of nutrients. RhopH3, unlike other RhopH proteins, is required for parasite invasion, suggesting some cellular processes RhopH proteins function as single players rather than a complex. We show the RhopH complex has not formed during merozoite invasion. Clag3 is directly released into the host cell cytoplasm, whilst RhopH2 and RhopH3 are released into the nascent parasitophorous vacuole. Export of RhopH2 and RhopH3 from the parasitophorous vacuole into the infected erythrocyte cytoplasm enables assembly of Clag3/RhopH2/RhopH3 complexes and incorporation into the host cell membrane concomitant with activation of nutrient uptake. This suggests compartmentalisation prevents premature channel assembly before intact complex is assembled at the host cell membrane.
Collapse
Affiliation(s)
- Michał Pasternak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
- Imperial College London, London, SW7 2AZ, UK
| | - Julie M J Verhoef
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, Netherlands
| | - Wilson Wong
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Tony Triglia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Michael J Mlodzianoski
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Niall Geoghegan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Cindy Evelyn
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Ahmad Z Wardak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Kelly Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia.
| |
Collapse
|
9
|
Knudsen AS, Walker MR, Agullet JP, Björnsson KH, Bassi MR, Barfod L. Enhancing neutralization of Plasmodium falciparum using a novel monoclonal antibody against the rhoptry-associated membrane antigen. Sci Rep 2022; 12:3040. [PMID: 35197516 PMCID: PMC8866459 DOI: 10.1038/s41598-022-06921-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/31/2022] [Indexed: 11/09/2022] Open
Abstract
The pathogenesis of malaria is associated with blood-stage infection and there is strong evidence that antibodies specific to parasite blood-stage antigens can control parasitemia. This provides a strong rational for applying blood-stage antigen components in a multivalent vaccine, as the induced antibodies in combination can enhance protection. The Plasmodium falciparum rhoptry-associated membrane antigen (PfRAMA) is a promising vaccine target, due to its fundamental role in merozoite invasion and low level of polymorphism. Polyclonal antibodies against PfRAMA are able to inhibit P. falciparum growth and interact synergistically when combined with antibodies against P. falciparum reticulocyte-binding protein 5 (PfRh5) or cysteine-rich protective antigen (PfCyRPA). In this study, we identified a novel PfRAMA-specific mAb with neutralizing activity, which in combination with PfRh5- or PfCyRPA-specific mAbs potentiated the neutralizing effect. By applying phage display technology, we mapped the protective epitope to be in the C-terminal region of PfRAMA. Our results confirmed previous finding of synergy between PfRAMA-, PfRh5- and PfCyRPA-specific antibodies, thereby paving the way of testing these antigens (or fragments of these antigens) in combination to improve the efficacy of blood-stage malaria vaccines. The results emphasize the importance of directing antibody responses towards protective epitopes, as the majority of anti-PfRAMA mAbs were unable to inhibit merozoite invasion of erythrocytes.
Collapse
Affiliation(s)
- Anne S Knudsen
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Melanie R Walker
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Judit P Agullet
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kasper H Björnsson
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria R Bassi
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lea Barfod
- Department of Immunology and Microbiology, Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
10
|
Frasse PM, Miller JJ, Polino AJ, Soleimani E, Zhu JS, Jakeman DL, Jez JM, Goldberg DE, Odom John AR. Enzymatic and structural characterization of HAD5, an essential phosphomannomutase of malaria-causing parasites. J Biol Chem 2022; 298:101550. [PMID: 34973333 PMCID: PMC8808168 DOI: 10.1016/j.jbc.2021.101550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/05/2022] Open
Abstract
The malaria-causing parasite Plasmodium falciparum is responsible for over 200 million infections and 400,000 deaths per year. At multiple stages during its complex life cycle, P. falciparum expresses several essential proteins tethered to its surface by glycosylphosphatidylinositol (GPI) anchors, which are critical for biological processes such as parasite egress and reinvasion of host red blood cells. Targeting this pathway therapeutically has the potential to broadly impact parasite development across several life stages. Here, we characterize an upstream component of parasite GPI anchor biosynthesis, the putative phosphomannomutase (PMM) (EC 5.4.2.8), HAD5 (PF3D7_1017400). We confirmed the PMM and phosphoglucomutase activities of purified recombinant HAD5 by developing novel linked enzyme biochemical assays. By regulating the expression of HAD5 in transgenic parasites with a TetR-DOZI-inducible knockdown system, we demonstrated that HAD5 is required for malaria parasite egress and erythrocyte reinvasion, and we assessed the role of HAD5 in GPI anchor synthesis by autoradiography of radiolabeled glucosamine and thin layer chromatography. Finally, we determined the three-dimensional X-ray crystal structure of HAD5 and identified a substrate analog that specifically inhibits HAD5 compared to orthologous human PMMs in a time-dependent manner. These findings demonstrate that the GPI anchor biosynthesis pathway is exceptionally sensitive to inhibition in parasites and that HAD5 has potential as a specific, multistage antimalarial target.
Collapse
Affiliation(s)
- Philip M Frasse
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Justin J Miller
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alexander J Polino
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ebrahim Soleimani
- College of Pharmacy, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Chemistry, Razi University, Kermanshah, Iran
| | - Jian-She Zhu
- College of Pharmacy, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David L Jakeman
- College of Pharmacy, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Audrey R Odom John
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
11
|
Ahmed MA, Deshmukh GY, Zaidi RH, Saif A, Alshahrani MA, Wazid SW, Patgiri SJ, Quan FS. Identification, Mapping, and Genetic Diversity of Novel Conserved Cross-Species Epitopes of RhopH2 in Plasmodium knowlesi With Plasmodium vivax. Front Cell Infect Microbiol 2022; 11:810398. [PMID: 35096656 PMCID: PMC8793677 DOI: 10.3389/fcimb.2021.810398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
Malaria is a major public health concern, and any tangible intervention during the pre-elimination phase can result in a significant reduction in infection rates. Recent studies have reported that antigens producing cross-protective immunity can play an important role as vaccines and halt malaria transmission in different endemic regions. In this study, we studied the genetic diversity, natural selection, and discovered novel conserved epitopes of a high molecular weight rhoptry protein 2 (RhopH2) in clinical samples of Plasmodium knowlesi and Plasmodium vivax cross-protective domains, which has been proven to produce cross-protective immunity in both species. We found low levels of nucleotide diversity (P. knowlesi; π ~ 0.0093, SNPs = 49 and P. vivax π ~ 0.0014, SNPs = 23) in P. knowlesi (n = 40) and P. vivax (n = 65) samples in the PkRhopH2 cross-protective domain. Strong purifying selection was observed for both species (P. knowlesi; dS - dN = 2.41, p < 0.009, P. vivax; dS - dN = 1.58, p < 0.050). In silico epitope prediction in P. knowlesi identified 10 potential epitopes, of which 7 epitopes were 100% conserved within clinical samples. Of these epitopes, an epitope with 10 amino acids (QNSKHFKKEK) was found to be fully conserved within all P. knowlesi and P. vivax clinical samples and 80%–90% conservation within simian malaria ortholog species, i.e., P. coatneyi and P. cynomolgi. Phylogenetic analysis of the PkRhopH2 cross-protective domain showed geographical clustering, and three subpopulations of P. knowlesi were identified of which two subpopulations originated from Sarawak, Malaysian Borneo, and one comprised only the laboratory lines from Peninsular Malaysia. This study suggests that RhopH2 could be an excellent target for cross-protective vaccine development with potential for outwitting strain as well as species-specific immunity. However, more detailed studies on genetic diversity using more clinical samples from both species as well as the functional role of antibodies specific to the novel conserved epitope identified in this study can be explored for protection against infection.
Collapse
Affiliation(s)
- Md Atique Ahmed
- Indian Council of Medical Research (ICMR)-Regional Medical Research Centre, North East Region (NER), Dibrugarh, India
- *Correspondence: Md Atique Ahmed, ; Fu-Shi Quan,
| | | | - Rehan Haider Zaidi
- Department of Biotechnology and Microbiology, National College, Tiruchirapalli, India
| | - Ahmed Saif
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Najran University, Narjan, Saudi Arabia
| | | | | | - Saurav Jyoti Patgiri
- Indian Council of Medical Research (ICMR)-Regional Medical Research Centre, North East Region (NER), Dibrugarh, India
| | - Fu-Shi Quan
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul, South Korea
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
- *Correspondence: Md Atique Ahmed, ; Fu-Shi Quan,
| |
Collapse
|
12
|
Djokic V, Rocha SC, Parveen N. Lessons Learned for Pathogenesis, Immunology, and Disease of Erythrocytic Parasites: Plasmodium and Babesia. Front Cell Infect Microbiol 2021; 11:685239. [PMID: 34414129 PMCID: PMC8369351 DOI: 10.3389/fcimb.2021.685239] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/15/2021] [Indexed: 11/24/2022] Open
Abstract
Malaria caused by Plasmodium species and transmitted by Anopheles mosquitoes affects large human populations, while Ixodes ticks transmit Babesia species and cause babesiosis. Babesiosis in animals has been known as an economic drain, and human disease has also emerged as a serious healthcare problem in the last 20–30 years. There is limited literature available regarding pathogenesis, immunity, and disease caused by Babesia spp. with their genomes sequenced only in the last decade. Therefore, using previous studies on Plasmodium as the foundation, we have compared similarities and differences in the pathogenesis of Babesia and host immune responses. Sexual life cycles of these two hemoparasites in their respective vectors are quite similar. An adult Anopheles female can take blood meal several times in its life such that it can both acquire and transmit Plasmodia to hosts. Since each tick stage takes blood meal only once, transstadial horizontal transmission from larva to nymph or nymph to adult is essential for the release of Babesia into the host. The initiation of the asexual cycle of these parasites is different because Plasmodium sporozoites need to infect hepatocytes before egressed merozoites can infect erythrocytes, while Babesia sporozoites are known to enter the erythrocytic cycle directly. Plasmodium metabolism, as determined by its two- to threefold larger genome than different Babesia, is more complex. Plasmodium replication occurs in parasitophorous vacuole (PV) within the host cells, and a relatively large number of merozoites are released from each infected RBC after schizogony. The Babesia erythrocytic cycle lacks both PV and schizogony. Cytoadherence that allows the sequestration of Plasmodia, primarily P. falciparum in different organs facilitated by prominent adhesins, has not been documented for Babesia yet. Inflammatory immune responses contribute to the severity of malaria and babesiosis. Antibodies appear to play only a minor role in the resolution of these diseases; however, cellular and innate immunity are critical for the clearance of both pathogens. Inflammatory immune responses affect the severity of both diseases. Macrophages facilitate the resolution of both infections and also offer cross-protection against related protozoa. Although the immunosuppression of adaptive immune responses by these parasites does not seem to affect their own clearance, it significantly exacerbates diseases caused by coinfecting bacteria during coinfections.
Collapse
Affiliation(s)
- Vitomir Djokic
- Department for Bacterial Zoonozes, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health & Safety, UPEC, University Paris-Est, Maisons-Alfort, France
| | - Sandra C Rocha
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Nikhat Parveen
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, United States
| |
Collapse
|
13
|
4D analysis of malaria parasite invasion offers insights into erythrocyte membrane remodeling and parasitophorous vacuole formation. Nat Commun 2021; 12:3620. [PMID: 34131147 PMCID: PMC8206130 DOI: 10.1038/s41467-021-23626-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 04/30/2021] [Indexed: 12/15/2022] Open
Abstract
Host membrane remodeling is indispensable for viruses, bacteria, and parasites, to subvert the membrane barrier and obtain entry into cells. The malaria parasite Plasmodium spp. induces biophysical and molecular changes to the erythrocyte membrane through the ordered secretion of its apical organelles. To understand this process and address the debate regarding how the parasitophorous vacuole membrane (PVM) is formed, we developed an approach using lattice light-sheet microscopy, which enables the parasite interaction with the host cell membrane to be tracked and characterized during invasion. Our results show that the PVM is predominantly formed from the erythrocyte membrane, which undergoes biophysical changes as it is remodeled across all stages of invasion, from pre-invasion through to PVM sealing. This approach enables a functional interrogation of parasite-derived lipids and proteins in PVM biogenesis and echinocytosis during Plasmodium falciparum invasion and promises to yield mechanistic insights regarding how this is more generally orchestrated by other intracellular pathogens. Here, Geoghegan, Evelyn et al. provide a lattice light-sheet microscopy based 4D imaging pipeline to quantitatively investigate Plasmodium spp. invasion and show that the nascent parasitophorous vacuole is predominantly formed from host’s erythrocyte membrane and undergoes continuous remodeling throughout invasion.
Collapse
|
14
|
Liffner B, Balbin JM, Wichers JS, Gilberger TW, Wilson DW. The Ins and Outs of Plasmodium Rhoptries, Focusing on the Cytosolic Side. Trends Parasitol 2021; 37:638-650. [PMID: 33941492 DOI: 10.1016/j.pt.2021.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/19/2021] [Accepted: 03/15/2021] [Indexed: 01/13/2023]
Abstract
Parasites of the genus Plasmodium cause human and animal malaria, leading to significant health and economic impacts. A key aspect of the complex life cycle of Plasmodium parasites is the invasion of the parasite into its host cell, which is mediated by secretory organelles. The largest of these organelles, the rhoptry, undergoes rapid and profound physiological changes when it secretes its contents during merozoite and sporozoite invasion of the host erythrocyte and hepatocyte, respectively. Here we discuss recent advancements in our understanding of the dynamic rhoptry biology during the parasite's invasive stages, with a focus on the roles of cytosolically exposed rhoptry-interacting proteins (C-RIPs). We explore potential similarities between the molecular mechanisms driving merozoite and sporozoite rhoptry function.
Collapse
Affiliation(s)
- Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Juan Miguel Balbin
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Jan Stephan Wichers
- Centre for Structural Systems Biology, 22607, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Tim-Wolf Gilberger
- Centre for Structural Systems Biology, 22607, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; Biology Department, University of Hamburg, 20146 Hamburg, Germany
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide 5005, Australia; Burnet Institute, 85 Commercial Road, Melbourne 3004, Victoria, Australia.
| |
Collapse
|
15
|
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: 42] [Impact Index Per Article: 14.0] [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
|
16
|
Ito D, Chen JH, Takashima E, Hasegawa T, Otsuki H, Takeo S, Thongkukiatkul A, Han ET, Tsuboi T. Identification of a Novel RAMA/RON3 Rhoptry Protein Complex in Plasmodium falciparum Merozoites. Front Cell Infect Microbiol 2021; 10:605367. [PMID: 33537242 PMCID: PMC7848174 DOI: 10.3389/fcimb.2020.605367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/27/2020] [Indexed: 01/08/2023] Open
Abstract
Malaria causes a half a million deaths annually. The parasite intraerythrocytic lifecycle in the human bloodstream is the major cause of morbidity and mortality. Apical organelles of merozoite stage parasites are involved in the invasion of erythrocytes. A limited number of apical organellar proteins have been identified and characterized for their roles during erythrocyte invasion or subsequent intraerythrocytic parasite development. To expand the repertoire of identified apical organellar proteins we generated a panel of monoclonal antibodies against Plasmodium falciparum schizont-rich parasites and screened the antibodies using immunofluorescence assays. Out of 164 hybridoma lines, 12 clones produced monoclonal antibodies yielding punctate immunofluorescence staining patterns in individual merozoites in late schizonts, suggesting recognition of merozoite apical organelles. Five of the monoclonal antibodies were used to immuno-affinity purify their target antigens and these antigens were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two known apical organelle protein complexes were identified, the high-molecular mass rhoptry protein complex (PfRhopH1/Clags, PfRhopH2, and PfRhopH3) and the low-molecular mass rhoptry protein complex (rhoptry-associated proteins complex, PfRAP1, and PfRAP2). A novel complex was additionally identified by immunoprecipitation, composed of rhoptry-associated membrane antigen (PfRAMA) and rhoptry neck protein 3 (PfRON3) of P. falciparum. We further identified a region spanning amino acids Q221-E481 within the PfRAMA that may associate with PfRON3 in immature schizonts. Further investigation will be required as to whether PfRAMA and PfRON3 interact directly or indirectly.
Collapse
Affiliation(s)
- Daisuke Ito
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan.,Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Tomoyuki Hasegawa
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Satoru Takeo
- Division of Tropical Diseases and Parasitology, Department of Infectious Diseases, Faculty of Medicine, Kyorin University, Mitaka, Japan
| | | | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| |
Collapse
|
17
|
Phosphorylation of Rhoptry Protein RhopH3 Is Critical for Host Cell Invasion by the Malaria Parasite. mBio 2020; 11:mBio.00166-20. [PMID: 33024030 PMCID: PMC7542355 DOI: 10.1128/mbio.00166-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Host cell invasion by the malaria parasite is critical for establishing infection in human host and is dependent on discharge of key ligands from organelles like rhoptry and microneme, and these ligands interact with host RBC receptors. In the present study, we demonstrate that phosphorylation of a key rhoptry protein, RhopH3, is critical for host invasion. Phosphorylation regulates its localization to rhoptries and discharge from the parasite. Merozoites formed after asexual division of the malaria parasite invade the host red blood cells (RBCs), which is critical for initiating malaria infection. The process of invasion involves specialized organelles like micronemes and rhoptries that discharge key proteins involved in interaction with host RBC receptors. RhopH complex comprises at least three proteins, which include RhopH3. RhopH3 is critical for the process of red blood cell (RBC) invasion as well as intraerythrocytic development of human malaria parasite Plasmodium falciparum. It is phosphorylated at serine 804 (S804) in the parasite; however, it is unclear if phosphorylation regulates its function. To address this, a CRISPR-CAS9-based approach was used to mutate S804 to alanine (A) in P. falciparum. Using this phosphomutant (R3_S804A) of RhopH3, we demonstrate that the phosphorylation of S804 is critical for host RBC invasion by the parasite but not for its intraerythrocytic development. Importantly, the phosphorylation of RhopH3 regulates its localization to the rhoptries and discharge from the parasite, which is critical for RBC invasion. We also identified P. falciparum CDPK1 (PfCDPK1) as a possible candidate kinase for RhopH3-S804 phosphorylation and found that it regulates RhopH3 secretion from the parasite. These findings provide novel insights into the role of phosphorylation in rhoptry release and invasion, which is poorly understood.
Collapse
|