1
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Tang WK, Salinas ND, Kolli SK, Xu S, Urusova DV, Kumar H, Jimah JR, Subramani PA, Ogbondah MM, Barnes SJ, Adams JH, Tolia NH. Multistage protective anti-CelTOS monoclonal antibodies with cross-species sterile protection against malaria. Nat Commun 2024; 15:7487. [PMID: 39209843 PMCID: PMC11362571 DOI: 10.1038/s41467-024-51701-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 08/15/2024] [Indexed: 09/04/2024] Open
Abstract
CelTOS is a malaria vaccine antigen that is conserved in Plasmodium and other apicomplexan parasites and plays a role in cell-traversal. The structural basis and mechanisms of CelTOS-induced protective immunity to parasites are unknown. Here, CelTOS-specific monoclonal antibodies (mAbs) 7g7 and 4h12 demonstrated multistage activity, protecting against liver infection and preventing parasite transmission to mosquitoes. Both mAbs demonstrated cross-species activity with sterile protection against in vivo challenge with transgenic parasites containing either P. falciparum or P. vivax CelTOS, and with transmission reducing activity against P. falciparum. The mAbs prevented CelTOS-mediated pore formation providing insight into the protective mechanisms. X-ray crystallography and mutant-library epitope mapping revealed two distinct broadly conserved neutralizing epitopes. 7g7 bound to a parallel dimer of CelTOS, while 4h12 bound to a novel antiparallel dimer architecture. These findings inform the design of antibody therapies and vaccines and raise the prospect of a single intervention to simultaneously combat P. falciparum and P. vivax malaria.
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MESH Headings
- Antibodies, Monoclonal/immunology
- Animals
- Plasmodium falciparum/immunology
- Plasmodium vivax/immunology
- Malaria Vaccines/immunology
- Antibodies, Protozoan/immunology
- Mice
- Malaria, Falciparum/immunology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/parasitology
- Crystallography, X-Ray
- Epitopes/immunology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Antigens, Protozoan/immunology
- Humans
- Female
- Epitope Mapping
- Malaria/immunology
- Malaria/prevention & control
- Malaria/parasitology
- Mice, Inbred BALB C
- Protozoan Proteins/immunology
- Protozoan Proteins/chemistry
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Affiliation(s)
- Wai Kwan Tang
- Host‒Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Nichole D Salinas
- Host‒Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Surendra Kumar Kolli
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Shulin Xu
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Darya V Urusova
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hirdesh Kumar
- Host‒Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - John R Jimah
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Pradeep Annamalai Subramani
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Madison M Ogbondah
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Samantha J Barnes
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - John H Adams
- Center of Global Health and Interdisciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Niraj H Tolia
- Host‒Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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2
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Ma R, Salinas ND, Orr-Gonzalez S, Richardson B, Ouahes T, Torano H, Jenkins BJ, Dickey TH, Neal J, Duan J, Morrison RD, Gittis AG, Doritchamou JYA, Zaidi I, Lambert LE, Duffy PE, Tolia NH. Structure-guided design of VAR2CSA-based immunogens and a cocktail strategy for a placental malaria vaccine. PLoS Pathog 2024; 20:e1011879. [PMID: 38437239 PMCID: PMC10939253 DOI: 10.1371/journal.ppat.1011879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 03/14/2024] [Accepted: 11/29/2023] [Indexed: 03/06/2024] Open
Abstract
Placental accumulation of Plasmodium falciparum infected erythrocytes results in maternal anemia, low birth weight, and pregnancy loss. The parasite protein VAR2CSA facilitates the accumulation of infected erythrocytes in the placenta through interaction with the host receptor chondroitin sulfate A (CSA). Antibodies that prevent the VAR2CSA-CSA interaction correlate with protection from placental malaria, and VAR2CSA is a high-priority placental malaria vaccine antigen. Here, structure-guided design leveraging the full-length structures of VAR2CSA produced a stable immunogen that retains the critical conserved functional elements of VAR2CSA. The design expressed with a six-fold greater yield than the full-length protein and elicited antibodies that prevent adhesion of infected erythrocytes to CSA. The reduced size and adaptability of the designed immunogen enable efficient production of multiple variants of VAR2CSA for use in a cocktail vaccination strategy to increase the breadth of protection. These designs form strong foundations for the development of potent broadly protective placental malaria vaccines.
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Affiliation(s)
- Rui Ma
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nichole D Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sachy Orr-Gonzalez
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brandi Richardson
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Holly Torano
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Bethany J Jenkins
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jillian Neal
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Junhui Duan
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert D Morrison
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Apostolos G Gittis
- Structural Biology Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Justin Y A Doritchamou
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Irfan Zaidi
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lynn E Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Patrick E Duffy
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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3
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Baro B, Kim CY, Lin C, Kongsomboonvech AK, Tetard M, Peterson NA, Salinas ND, Tolia NH, Egan ES. Plasmodium falciparum exploits CD44 as a coreceptor for erythrocyte invasion. Blood 2023; 142:2016-2028. [PMID: 37832027 PMCID: PMC10783654 DOI: 10.1182/blood.2023020831] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 09/08/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023] Open
Abstract
The malaria parasite Plasmodium falciparum invades and replicates asexually within human erythrocytes. CD44 expressed on erythrocytes was previously identified as an important host factor for P falciparum infection through a forward genetic screen, but little is known about its regulation or function in these cells, nor how it may be used by the parasite. We found that CD44 can be efficiently deleted from primary human hematopoietic stem cells using CRISPR/Cas9 genome editing, and that the efficiency of ex vivo erythropoiesis to enucleated cultured red blood cells (cRBCs) is not affected by lack of CD44. However, the rate of P falciparum invasion was reduced in CD44-null cRBCs relative to isogenic wild-type control cells, validating CD44 as an important host factor for this parasite. We identified 2 P falciparum invasion ligands as binding partners for CD44, erythrocyte binding antigen 175 (EBA-175) and EBA-140 and demonstrated that their ability to bind to human erythrocytes relies primarily on their canonical receptors, glycophorin A and glycophorin C, respectively. We further show that EBA-175 induces phosphorylation of erythrocyte cytoskeletal proteins in a CD44-dependent manner. Our findings support a model in which P falciparum exploits CD44 as a coreceptor during invasion of human erythrocytes, stimulating CD44-dependent phosphorylation of host cytoskeletal proteins that alter host cell deformability and facilitate parasite entry.
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Affiliation(s)
- Barbara Baro
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | - Chi Yong Kim
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | - Carrie Lin
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | | | - Marilou Tetard
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | | | - Nichole D. Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Niraj H. Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Elizabeth S. Egan
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA
- Chan Zuckerberg Biohub–San Francisco, San Francisco, CA
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4
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Võ TC, Lê HG, Kang JM, Naw H, Yoo WG, Myint MK, Quang HH, Na BK. Genetic polymorphism and natural selection of the erythrocyte binding antigen 175 region II in Plasmodium falciparum populations from Myanmar and Vietnam. Sci Rep 2023; 13:20025. [PMID: 37973970 PMCID: PMC10654615 DOI: 10.1038/s41598-023-47275-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 11/11/2023] [Indexed: 11/19/2023] Open
Abstract
Plasmodium falciparum erythrocyte binding antigen 175 (PfEBA-175) plays essential role in erythrocyte invasion by the parasite and is a leading vaccine candidate. However, its genetic diversity in global isolates is a concern in developing an universal vaccine incorporating this protein. This study aimed to investigate genetic polymorphisms and natural selection of pfeba-175 region II (RII) in Myanmar and Vietnam P. falciparum isolates. Vietnam pfeba-175 RII displayed a low genetic polymorphism, while Myanmar pfeba-175 RII showed high levels of genetic diversity across the region. Point mutations, deletion, and recombinations were main factors contributing to genetic diversities in P. falciparum populations. Global pfeba-175 RII revealed similar, but not identical, genetic polymorphisms and natural selection profiles. Despite profiles of amino acid substitutions differed among populations, five major amino acid changes (K279E, E403K, K481I, Q584K, and R664) were commonly detected in global pfeba-175 RII populations. Haplotype network and genetic differentiation analyses of global pfeba-175 RII populations demonstrated no geographical relationships. Non-neglectable level of genetic diversity was observed in global pfeba-175 RII populations, emphasizing the need to consider this when designing an effective vaccine based on this protein. This study underscores the importance of the continuous monitoring of genetic diversity of pfeba-175 RII in the global P. falciparum populations.
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Affiliation(s)
- Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Hương Giang Lê
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Haung Naw
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Won Gi Yoo
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Moe Kyaw Myint
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Huynh Hong Quang
- Tropical Diseases Clinical and Treatment Research Department, Institute of Malariology, Parasitology, and Entomology Quy Nhon, Quy Nhon, Vietnam
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.
- Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea.
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5
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Shukla N, Tang WK, Coelho CH, Long CA, Healy SA, Sagara I, Miura K, Duffy PE, Tolia NH. A human antibody epitope map of the malaria vaccine antigen Pfs25. NPJ Vaccines 2023; 8:108. [PMID: 37542029 PMCID: PMC10403551 DOI: 10.1038/s41541-023-00712-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 07/12/2023] [Indexed: 08/06/2023] Open
Abstract
Pfs25 is a leading antigen for a malaria transmission-blocking vaccine and shows moderate transmission-blocking activity and induction of rapidly decreasing antibody titers in clinical trials. A comprehensive definition of all transmission-reducing epitopes of Pfs25 will inform structure-guided design to enhance Pfs25-based vaccines, leading to potent transmission-blocking activity. Here, we compiled a detailed human antibody epitope map comprising epitope binning data and structures of multiple human monoclonal antibodies, including three new crystal structures of Pfs25 in complex with transmission-reducing antibodies from Malian volunteers immunized with Pfs25 conjugated to EPA and adjuvanted with AS01. These structures revealed additional epitopes in Pfs25 capable of reducing transmission and expanded this characterization to malaria-exposed humans. This work informs immunogen design to focus the antibody response to transmission-reducing epitopes of Pfs25, enabling development of more potent transmission-blocking vaccines for malaria.
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Affiliation(s)
- Niharika Shukla
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Wai Kwan Tang
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Camila H Coelho
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
- Center for Vaccine Research and Pandemic Preparedness (C-VARPP), Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Sara A Healy
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Issaka Sagara
- Malaria Research and Training Center, University of Sciences, Techniques, and Technology, Bamako, Mali
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Patrick E Duffy
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, USA.
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6
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Baro-Sastre B, Kim CY, Lin C, Kongsomboonvech AK, Tetard M, Salinas ND, Tolia NH, Egan ES. Plasmodium falciparum exploits CD44 as a co-receptor for erythrocyte invasion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536503. [PMID: 37090581 PMCID: PMC10120705 DOI: 10.1101/2023.04.12.536503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
The malaria parasite Plasmodium falciparum invades and replicates asexually within human erythrocytes. CD44 expressed on erythrocytes was previously identified as an important host factor for P. falciparum infection through a forward genetic screen, but little is known about its regulation or function in these cells, nor how it may be utilized by the parasite. We found that CD44 can be efficiently deleted from primary human hematopoietic stem cells using CRISPR/Cas9 genome editing, and that the efficiency of ex-vivo erythropoiesis to enucleated cultured red blood cells (cRBCs) is not impacted by lack of CD44. However, the rate of P. falciparum invasion was substantially reduced in CD44-null cRBCs relative to isogenic wild-type (WT) control cells, validating CD44 as an important host factor for this parasite. We identified two P. falciparum invasion ligands as binding partners for CD44, Erythrocyte Binding Antigen-175 (EBA-175) and EBA-140, and demonstrated that their ability to bind to human erythrocytes relies primarily on their canonical receptors-glycophorin A and glycophorin C, respectively. We further show that EBA-175 induces phosphorylation of erythrocyte cytoskeletal proteins in a CD44-dependent manner. Our findings support a model where P. falciparum exploits CD44 as a co-receptor during invasion of human erythrocytes, stimulating CD44-dependent phosphorylation of host cytoskeletal proteins that alter host cell deformability and facilitate parasite entry.
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7
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Dickey TH, Gupta R, McAleese H, Ouahes T, Orr-Gonzalez S, Ma R, Muratova O, Salinas ND, Hume JCC, Lambert LE, Duffy PE, Tolia NH. Design of a stabilized non-glycosylated Pfs48/45 antigen enables a potent malaria transmission-blocking nanoparticle vaccine. NPJ Vaccines 2023; 8:20. [PMID: 36808125 PMCID: PMC9938515 DOI: 10.1038/s41541-023-00619-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/02/2023] [Indexed: 02/19/2023] Open
Abstract
A malaria vaccine that blocks parasite transmission from human to mosquito would be a powerful method of disrupting the parasite lifecycle and reducing the incidence of disease in humans. Pfs48/45 is a promising antigen in development as a transmission blocking vaccine (TBV) against the deadliest malaria parasite Plasmodium falciparum. The third domain of Pfs48/45 (D3) is an established TBV candidate, but production challenges have hampered development. For example, to date, a non-native N-glycan is required to stabilize the domain when produced in eukaryotic systems. Here, we implement a SPEEDesign computational design and in vitro screening pipeline that retains the potent transmission blocking epitope in Pfs48/45 while creating a stabilized non-glycosylated Pfs48/45 D3 antigen with improved characteristics for vaccine manufacture. This antigen can be genetically fused to a self-assembling single-component nanoparticle, resulting in a vaccine that elicits potent transmission-reducing activity in rodents at low doses. The enhanced Pfs48/45 antigen enables many new and powerful approaches to TBV development, and this antigen design method can be broadly applied towards the design of other vaccine antigens and therapeutics without interfering glycans.
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Affiliation(s)
- Thayne H. Dickey
- grid.94365.3d0000 0001 2297 5165Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Richi Gupta
- grid.94365.3d0000 0001 2297 5165Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Holly McAleese
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Tarik Ouahes
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Sachy Orr-Gonzalez
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Rui Ma
- grid.94365.3d0000 0001 2297 5165Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Olga Muratova
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Nichole D. Salinas
- grid.94365.3d0000 0001 2297 5165Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Jen C. C. Hume
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Lynn E. Lambert
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Patrick E. Duffy
- grid.94365.3d0000 0001 2297 5165Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA ,grid.94365.3d0000 0001 2297 5165Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
| | - Niraj H. Tolia
- grid.94365.3d0000 0001 2297 5165Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, MD USA
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8
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Chandley P, Ranjan R, Kumar S, Rohatgi S. Host-parasite interactions during Plasmodium infection: Implications for immunotherapies. Front Immunol 2023; 13:1091961. [PMID: 36685595 PMCID: PMC9845897 DOI: 10.3389/fimmu.2022.1091961] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/12/2022] [Indexed: 01/05/2023] Open
Abstract
Malaria is a global infectious disease that remains a leading cause of morbidity and mortality in the developing world. Multiple environmental and host and parasite factors govern the clinical outcomes of malaria. The host immune response against the Plasmodium parasite is heterogenous and stage-specific both in the human host and mosquito vector. The Plasmodium parasite virulence is predominantly associated with its ability to evade the host's immune response. Despite the availability of drug-based therapies, Plasmodium parasites can acquire drug resistance due to high antigenic variations and allelic polymorphisms. The lack of licensed vaccines against Plasmodium infection necessitates the development of effective, safe and successful therapeutics. To design an effective vaccine, it is important to study the immune evasion strategies and stage-specific Plasmodium proteins, which are targets of the host immune response. This review provides an overview of the host immune defense mechanisms and parasite immune evasion strategies during Plasmodium infection. Furthermore, we also summarize and discuss the current progress in various anti-malarial vaccine approaches, along with antibody-based therapy involving monoclonal antibodies, and research advancements in host-directed therapy, which can together open new avenues for developing novel immunotherapies against malaria infection and transmission.
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Affiliation(s)
- Pankaj Chandley
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ravikant Ranjan
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Sudhir Kumar
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Soma Rohatgi
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India,*Correspondence: Soma Rohatgi,
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9
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Tichkule S, Myung Y, Naung MT, Ansell BRE, Guy AJ, Srivastava N, Mehra S, Cacciò SM, Mueller I, Barry AE, van Oosterhout C, Pope B, Ascher DB, Jex AR. VIVID: a web application for variant interpretation and visualisation in multidimensional analyses. Mol Biol Evol 2022; 39:6697981. [PMID: 36103257 PMCID: PMC9514033 DOI: 10.1093/molbev/msac196] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Large-scale comparative genomics- and population genetic studies generate enormous amounts of polymorphism data in the form of DNA variants. Ultimately, the goal of many of these studies is to associate genetic variants to phenotypes or fitness. We introduce VIVID, an interactive, user-friendly web application that integrates a wide range of approaches for encoding genotypic to phenotypic information in any organism or disease, from an individual or population, in three-dimensional (3D) space. It allows mutation mapping and annotation, calculation of interactions and conservation scores, prediction of harmful effects, analysis of diversity and selection, and 3D visualization of genotypic information encoded in Variant Call Format on AlphaFold2 protein models. VIVID enables the rapid assessment of genes of interest in the study of adaptive evolution and the genetic load, and it helps prioritizing targets for experimental validation. We demonstrate the utility of VIVID by exploring the evolutionary genetics of the parasitic protist Plasmodium falciparum, revealing geographic variation in the signature of balancing selection in potential targets of functional antibodies.
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Affiliation(s)
- Swapnil Tichkule
- Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
- Department of Medical Biology, University of Melbourne , Melbourne , Australia
| | - Yoochan Myung
- Systems and Computational Biology, Bio21 Institute, University of Melbourne , Melbourne , Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes , Melbourne , Australia
| | - Myo T Naung
- Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
- Department of Medical Biology, University of Melbourne , Melbourne , Australia
| | - Brendan R E Ansell
- Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
| | - Andrew J Guy
- School of Science, RMIT University , Melbourne , Australia
| | - Namrata Srivastava
- Department of Data Science and AI, Monash University , Melbourne , Australia
| | - Somya Mehra
- Life Sciences Discipline, Burnet Institute , Melbourne , Australia
| | - Simone M Cacciò
- Department of Infectious Disease, Istituto Superiore di Sanità , Rome , Italy
| | - Ivo Mueller
- Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
| | - Alyssa E Barry
- Life Sciences Discipline, Burnet Institute , Melbourne , Australia
- Institute of Mental and Physical Health and Clinical Translation (IMPACT) and School of Medicine, Deakin University , Geelong , Australia
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich Research Park , Norwich , UK
| | - Bernard Pope
- Melbourne Bioinformatics, University of Melbourne , Melbourne , Australia
- Australian BioCommons , Sydney , Australia
- Department of Clinical Pathology, University of Melbourne , Melbourne , Australia
- Department of Surgery (Royal Melbourne Hospital), University of Melbourne , Melbourne , Australia
| | - David B Ascher
- Systems and Computational Biology, Bio21 Institute, University of Melbourne , Melbourne , Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes , Melbourne , Australia
| | - Aaron R Jex
- Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne , Melbourne , Australia
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10
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Naung MT, Martin E, Munro J, Mehra S, Guy AJ, Laman M, Harrison GLA, Tavul L, Hetzel M, Kwiatkowski D, Mueller I, Bahlo M, Barry AE. Global diversity and balancing selection of 23 leading Plasmodium falciparum candidate vaccine antigens. PLoS Comput Biol 2022; 18:e1009801. [PMID: 35108259 PMCID: PMC8843232 DOI: 10.1371/journal.pcbi.1009801] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 02/14/2022] [Accepted: 01/03/2022] [Indexed: 12/30/2022] Open
Abstract
Investigation of the diversity of malaria parasite antigens can help prioritize and validate them as vaccine candidates and identify the most common variants for inclusion in vaccine formulations. Studies of vaccine candidates of the most virulent human malaria parasite, Plasmodium falciparum, have focused on a handful of well-known antigens, while several others have never been studied. Here we examine the global diversity and population structure of leading vaccine candidate antigens of P. falciparum using the MalariaGEN Pf3K (version 5.1) resource, comprising more than 2600 genomes from 15 malaria endemic countries. A stringent variant calling pipeline was used to extract high quality antigen gene 'haplotypes' from the global dataset and a new R-package named VaxPack was used to streamline population genetic analyses. In addition, a newly developed algorithm that enables spatial averaging of selection pressure on 3D protein structures was applied to the dataset. We analysed the genes encoding 23 leading and novel candidate malaria vaccine antigens including csp, trap, eba175, ama1, rh5, and CelTOS. Our analysis shows that current malaria vaccine formulations are based on rare haplotypes and thus may have limited efficacy against natural parasite populations. High levels of diversity with evidence of balancing selection was detected for most of the erythrocytic and pre-erythrocytic antigens. Measures of natural selection were then mapped to 3D protein structures to predict targets of functional antibodies. For some antigens, geographical variation in the intensity and distribution of these signals on the 3D structure suggests adaptation to different human host or mosquito vector populations. This study provides an essential framework for the diversity of P. falciparum antigens to be considered in the design of the next generation of malaria vaccines.
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Affiliation(s)
- Myo T. Naung
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
- Institute of Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Elijah Martin
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Life Sciences Discipline, Burnet Institute, Melbourne, Victoria, Australia
| | - Jacob Munro
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Somya Mehra
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Life Sciences Discipline, Burnet Institute, Melbourne, Victoria, Australia
| | - Andrew J. Guy
- School of Science, RMIT University, Melbourne, Victoria, Australia
| | - Moses Laman
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - G. L. Abby Harrison
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
| | - Livingstone Tavul
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Manuel Hetzel
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Dominic Kwiatkowski
- Sanger Institute, Hinxton, United Kingdom
- Big Data Institute, University of Oxford, Oxford, United Kingdom
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
- Division of Parasites and Insect Vectors, Pasteur Institute, Paris, France
| | - Melanie Bahlo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
| | - Alyssa E. Barry
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
- Institute of Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Geelong, Victoria, Australia
- Life Sciences Discipline, Burnet Institute, Melbourne, Victoria, Australia
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11
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Longoni SS, Tiberti N, Bisoffi Z, Piubelli C. Monoclonal Antibodies for Protozoan Infections: A Future Reality or a Utopic Idea? Front Med (Lausanne) 2021; 8:745665. [PMID: 34712683 PMCID: PMC8545981 DOI: 10.3389/fmed.2021.745665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/17/2021] [Indexed: 12/15/2022] Open
Abstract
Following the SARS-CoV-2 pandemic, several clinical trials have been approved for the investigation of the possible use of mAbs, supporting the potential of this technology as a therapeutic approach for infectious diseases. The first monoclonal antibody (mAb), Muromonab CD3, was introduced for the prevention of kidney transplant rejection more than 30 years ago; since then more than 100 mAbs have been approved for therapeutic purposes. Nonetheless, only four mAbs are currently employed for infectious diseases: Palivizumab, for the prevention of respiratory syncytial virus (RSV) infections, Raxibacumab and Obiltoxaximab, for the prophylaxis and treatment against anthrax toxin and Bezlotoxumab, for the prevention of Clostridium difficile recurrence. Protozoan infections are often neglected diseases for which effective and safe chemotherapies are generally missing. In this context, drug resistance and drug toxicity are two crucial problems. The recent advances in bioinformatics, parasite genomics, and biochemistry methodologies are contributing to better understand parasite biology, which is essential to guide the development of new therapies. In this review, we present the efforts that are being made in the evaluation of mAbs for the prevention or treatment of leishmaniasis, Chagas disease, malaria, and toxoplasmosis. Particular emphasis will be placed on the potential strengths and weaknesses of biological treatments in the control of these protozoan diseases that are still affecting hundreds of thousands of people worldwide.
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Affiliation(s)
- Silvia Stefania Longoni
- Department of Infectious-Tropical Diseases and Microbiology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Sacro Cuore Don Calabria Hospital, Verona, Italy
| | - Natalia Tiberti
- Department of Infectious-Tropical Diseases and Microbiology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Sacro Cuore Don Calabria Hospital, Verona, Italy
| | - Zeno Bisoffi
- Department of Infectious-Tropical Diseases and Microbiology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Sacro Cuore Don Calabria Hospital, Verona, Italy.,Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Chiara Piubelli
- Department of Infectious-Tropical Diseases and Microbiology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Sacro Cuore Don Calabria Hospital, Verona, Italy
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12
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Yang PK, Liang XY, Lin M, Chen JT, Huang HY, Lin LY, Ehapo CS, Eyi UM, Zheng YZ, Xie DD, He JQ, Mo HT, Chen XY, Liu XZ, Wu YE. Population genetic analysis of the Plasmodium falciparum erythrocyte binding antigen-175 (EBA-175) gene in Equatorial Guinea. Malar J 2021; 20:374. [PMID: 34538247 PMCID: PMC8451130 DOI: 10.1186/s12936-021-03904-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/02/2021] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte binding antigen-175 (PfEBA-175) is a candidate antigen for a blood-stage malaria vaccine, while various polymorphisms and dimorphism have prevented to development of effective vaccines based on this gene. This study aimed to investigate the dimorphism of PfEBA-175 on both the Bioko Island and continent of Equatorial Guinea, as well as the genetic polymorphism and natural selection of global PfEBA-175. METHODS The allelic dimorphism of PfEBA-175 region II of 297 bloods samples from Equatorial Guinea in 2018 and 2019 were investigated by nested polymerase chain reaction and sequencing. Polymorphic characteristics and the effect of natural selection were analyzed using MEGA 7.0, DnaSP 6.0 and PopART programs. Protein function prediction of new amino acid mutation sites was performed using PolyPhen-2 and Foldx program. RESULTS Both Bioko Island and Bata district populations, the frequency of the F-fragment was higher than that of the C-fragment of PfEBA-175 gene. The PfEBA-175 of Bioko Island and Bata district isolates showed a high degree of genetic variability and heterogeneity, with π values of 0.00407 & 0.00411 and Hd values of 0.958 & 0.976 for nucleotide diversity, respectively. The values of Tajima's D of PfEBA-175 on Bata district and Bioko Island were 0.56395 and - 0.27018, respectively. Globally, PfEBA-175 isolates from Asia were more diverse than those from Africa and South America, and genetic differentiation quantified by the fixation index between Asian and South American countries populations was significant (FST > 0.15, P < 0.05). A total of 310 global isolates clustered in 92 haplotypes, and only one cluster contained isolates from three continents. The mutations A34T, K109E, D278Y, K301N, L305V and D329N were predicted as probably damaging. CONCLUSIONS This study demonstrated that the dimorphism of F-fragment PfEBA-175 was remarkably predominant in the study area. The distribution patterns and genetic diversity of PfEBA-175 in Equatorial Guinea isolates were similar another region isolates. And the levels of recombination events suggested that natural selection and intragenic recombination might be the main drivers of genetic diversity in global PfEBA-175. These results have important reference value for the development of blood-stage malaria vaccine based on this antigen.
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Affiliation(s)
- Pei-Kui Yang
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
- School of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Xue-Yan Liang
- Department of Clinical Laboratory, Huizhou Municipal Central Hospital, Huizhou, People's Republic of China
| | - Min Lin
- School of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Jiang-Tao Chen
- Department of Clinical Laboratory, Huizhou Municipal Central Hospital, Huizhou, People's Republic of China
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Hui-Ying Huang
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
- School of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Li-Yun Lin
- School of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Carlos Salas Ehapo
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - Urbano Monsuy Eyi
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - Yu-Zhong Zheng
- School of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Dong-De Xie
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Jin-Quan He
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Huan-Tong Mo
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Xin-Yao Chen
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Xiang-Zhi Liu
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China.
| | - Ying-E Wu
- Department of Medical Laboratory, First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong Province, People's Republic of China.
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13
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Patel PN, Tolia N. Structural vaccinology of malaria transmission-blocking vaccines. Expert Rev Vaccines 2021; 20:199-214. [PMID: 33430656 PMCID: PMC11077433 DOI: 10.1080/14760584.2021.1873135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023]
Abstract
Introduction: The development of effective vaccines remains a major health priority to combat the global burden of malaria, a life-threatening disease caused by Plasmodium parasites. Transmission-blocking vaccines (TBVs) elicit antibodies that neutralize the sexual stages of the parasite in blood meals ingested by the Anopheles mosquito, interrupting parasite development in the vector host and preventing disease spread to other individuals.Areas covered: The P. falciparum gametocyte surface antigens Pfs230, Pfs48/45, and Pfs47, the parasite ookinete surface protein Pfs25, and the male gametocyte specific protein PfHAP2 are leading TBV candidates, some of which are in clinical development. The recent expansion of methodology to study monoclonal antibodies isolated directly from humans and animal models, coupled with effective measures for parasite neutralization, has provided unprecedented insight into TBV efficacy and development.Expert opinion: Available structural and functional data on antigen-monoclonal antibody (Ag-mAb) complexes, as well as epitope classification studies, have identified neutralizing epitopes that may aid vaccine development and improve protection. Here, we review the clinical prospects of TBV candidates, progress in the development of novel vaccine strategies for TBVs, and the impact of structural vaccinology in TBV design.
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Affiliation(s)
- Palak N Patel
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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14
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Hotspots in Plasmodium and RBC Receptor-Ligand Interactions: Key Pieces for Inhibiting Malarial Parasite Invasion. Int J Mol Sci 2020; 21:ijms21134729. [PMID: 32630804 PMCID: PMC7370042 DOI: 10.3390/ijms21134729] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/15/2020] [Accepted: 05/24/2020] [Indexed: 11/17/2022] Open
Abstract
Protein-protein interactions (IPP) play an essential role in practically all biological processes, including those related to microorganism invasion of their host cells. It has been found that a broad repertoire of receptor-ligand interactions takes place in the binding interphase with host cells in malaria, these being vital interactions for successful parasite invasion. Several trials have been conducted for elucidating the molecular interface of interactions between some Plasmodium falciparum and Plasmodium vivax antigens with receptors on erythrocytes and/or reticulocytes. Structural information concerning these complexes is available; however, deeper analysis is required for correlating structural, functional (binding, invasion, and inhibition), and polymorphism data for elucidating new interaction hotspots to which malaria control methods can be directed. This review describes and discusses recent structural and functional details regarding three relevant interactions during erythrocyte invasion: Duffy-binding protein 1 (DBP1)–Duffy antigen receptor for chemokines (DARC); reticulocyte-binding protein homolog 5 (PfRh5)-basigin, and erythrocyte binding antigen 175 (EBA175)-glycophorin A (GPA).
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15
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Gunalan K, Gao X, Yap SSL, Lai SK, Ravasio A, Ganesan S, Li HY, Preiser PR. A processing product of the Plasmodium falciparum reticulocyte binding protein RH1 shows a close association with AMA1 during junction formation. Cell Microbiol 2020; 22:e13232. [PMID: 32452132 DOI: 10.1111/cmi.13232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/14/2020] [Accepted: 05/16/2020] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum responsible for the most virulent form of malaria invades human erythrocytes through multiple ligand-receptor interactions. The P. falciparum reticulocyte binding protein homologues (PfRHs) are expressed at the apical end of merozoites and form interactions with distinct erythrocyte surface receptors that are important for invasion. Here using a range of monoclonal antibodies (mAbs) against different regions of PfRH1 we have investigated the role of PfRH processing during merozoite invasion. We show that PfRH1 gets differentially processed during merozoite maturation and invasion and provide evidence that the different PfRH1 processing products have distinct functions during invasion. Using in-situ Proximity Ligation and FRET assays that allow probing of interactions at the nanometre level we show that a subset of PfRH1 products form close association with micronemal proteins Apical Membrane Antigen 1 (AMA1) in the moving junction suggesting a critical role in facilitating junction formation and active invasion. Our data provides evidence that time dependent processing of PfRH proteins is a mechanism by which the parasite is able to regulate distinct functional activities of these large processes. The identification of a specific close association with AMA1 in the junction now may also provide new avenues to target these interactions to prevent merozoite invasion.
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Affiliation(s)
- Karthigayan Gunalan
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Xiaohong Gao
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sally Shu Lin Yap
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Soak Kuan Lai
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Andrea Ravasio
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Institute of Biological and Medical Engineering of the Pontifical Catholic University of Chile, Chile
| | - Sundar Ganesan
- Research Technology Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Hoi Yeung Li
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Peter R Preiser
- Division of Molecular Genetics & Cell Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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16
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Guy AJ, Irani V, Richards JS, Ramsland PA. BioStructMap: a Python tool for integration of protein structure and sequence-based features. Bioinformatics 2019; 34:3942-3944. [PMID: 29931276 PMCID: PMC6223362 DOI: 10.1093/bioinformatics/bty474] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/18/2018] [Indexed: 12/22/2022] Open
Abstract
Summary A sliding window analysis over a protein or genomic sequence is commonly performed, and we present a Python tool, BioStructMap, that extends this concept to three-dimensional (3D) space, allowing the application of a 3D sliding window analysis over a protein structure. BioStructMap is easily extensible, allowing the user to apply custom functions to spatially aggregated data. BioStructMap also allows mapping of underlying genomic sequences to protein structures, allowing the user to perform genetic-based analysis over spatially linked codons-this has applications when selection pressures arise at the level of protein structure. Availability and implementation The Python BioStructMap package is available at https://github.com/andrewguy/biostructmap and released under the MIT License. An online server implementing standard functionality is available at https://biostructmap.burnet.edu.au. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Andrew J Guy
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Monash University, Melbourne, VIC, Australia
| | - Vashti Irani
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - Jack S Richards
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne, Melbourne, VIC, Australia.,Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia.,Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Paul A Ramsland
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology, Monash University, Melbourne, VIC, Australia.,Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia.,School of Science, RMIT University, Bundoora, VIC, Australia
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17
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Affiliation(s)
- Hirdesh Kumar
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Niraj H. Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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18
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Urusova D, Carias L, Huang Y, Nicolete VC, Popovici J, Roesch C, Salinas ND, Dechavanne S, Witkowski B, Ferreira MU, Adams JH, Gross ML, King CL, Tolia NH. Structural basis for neutralization of Plasmodium vivax by naturally acquired human antibodies that target DBP. Nat Microbiol 2019; 4:1486-1496. [PMID: 31133752 PMCID: PMC6707876 DOI: 10.1038/s41564-019-0461-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
Abstract
The Plasmodium vivax Duffy-binding protein (DBP) is a prime target of the protective immune response and a promising vaccine candidate for P. vivax malaria. Naturally acquired immunity (NAI) protects against malaria in adults residing in infection-endemic regions, and the passive transfer of malarial immunity confers protection. A vaccine that replicates NAI will effectively prevent disease. Here, we report the structures of DBP region II in complex with human-derived, neutralizing monoclonal antibodies obtained from an individual in a malaria-endemic area with NAI. We identified protective epitopes using X-ray crystallography, hydrogen-deuterium exchange mass spectrometry, mutational mapping and P. vivax invasion studies. These approaches reveal that naturally acquired human antibodies neutralize P. vivax by targeting the binding site for Duffy antigen receptor for chemokines (DARC) and the dimer interface of P. vivax DBP. Antibody binding is unaffected by polymorphisms in the vicinity of epitopes, suggesting that the antibodies have evolved to engage multiple polymorphic variants of DBP. The human antibody epitopes are broadly conserved and are distinct from previously defined epitopes for broadly conserved murine monoclonal antibodies. A library of globally conserved epitopes of neutralizing human antibodies offers possibilities for rational design of strain-transcending DBP-based vaccines and therapeutics against P. vivax.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing/chemistry
- Antibodies, Neutralizing/immunology
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/metabolism
- Binding Sites
- Crystallography, X-Ray
- Duffy Blood-Group System/metabolism
- Epitopes, B-Lymphocyte
- Erythrocytes/metabolism
- Erythrocytes/parasitology
- Genetic Variation
- Humans
- Malaria Vaccines/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Plasmodium vivax/genetics
- Plasmodium vivax/immunology
- Protein Binding
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/metabolism
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/metabolism
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Affiliation(s)
- Darya Urusova
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Lenore Carias
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Yining Huang
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
- Bioproduct Research and Development, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | | | - Jean Popovici
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | - Camille Roesch
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | - Nichole D Salinas
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sebastien Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | | | - John H Adams
- Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, USA.
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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19
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Julien JP, Wardemann H. Antibodies against Plasmodium falciparum malaria at the molecular level. Nat Rev Immunol 2019; 19:761-775. [DOI: 10.1038/s41577-019-0209-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 12/11/2022]
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20
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Vögtle T, Sharma S, Mori J, Nagy Z, Semeniak D, Scandola C, Geer MJ, Smith CW, Lane J, Pollack S, Lassila R, Jouppila A, Barr AJ, Ogg DJ, Howard TD, McMiken HJ, Warwicker J, Geh C, Rowlinson R, Abbott WM, Eckly A, Schulze H, Wright GJ, Mazharian A, Fütterer K, Rajesh S, Douglas MR, Senis YA. Heparan sulfates are critical regulators of the inhibitory megakaryocyte-platelet receptor G6b-B. eLife 2019; 8:e46840. [PMID: 31436532 PMCID: PMC6742478 DOI: 10.7554/elife.46840] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023] Open
Abstract
The immunoreceptor tyrosine-based inhibition motif (ITIM)-containing receptor G6b-B is critical for platelet production and activation. Loss of G6b-B results in severe macrothrombocytopenia, myelofibrosis and aberrant platelet function in mice and humans. Using a combination of immunohistochemistry, affinity chromatography and proteomics, we identified the extracellular matrix heparan sulfate (HS) proteoglycan perlecan as a G6b-B binding partner. Subsequent in vitro biochemical studies and a cell-based genetic screen demonstrated that the interaction is specifically mediated by the HS chains of perlecan. Biophysical analysis revealed that heparin forms a high-affinity complex with G6b-B and mediates dimerization. Using platelets from humans and genetically modified mice, we demonstrate that binding of G6b-B to HS and multivalent heparin inhibits platelet and megakaryocyte function by inducing downstream signaling via the tyrosine phosphatases Shp1 and Shp2. Our findings provide novel insights into how G6b-B is regulated and contribute to our understanding of the interaction of megakaryocytes and platelets with glycans.
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Affiliation(s)
- Timo Vögtle
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Sumana Sharma
- Cell Surface Signalling LaboratoryWellcome Trust Sanger InstituteCambridgeUnited Kingdom
| | - Jun Mori
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Zoltan Nagy
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Daniela Semeniak
- Institute of Experimental BiomedicineUniversity Hospital WürzburgWürzburgGermany
| | - Cyril Scandola
- Université de Strasbourg, Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de StrasbourgStrasbourgFrance
| | - Mitchell J Geer
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Christopher W Smith
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Jordan Lane
- Sygnature Discovery LimitedNottinghamUnited Kingdom
| | | | - Riitta Lassila
- Coagulation Disorders Unit, Department of Hematology, Comprehensive Cancer CenterUniversity of Helsinki, Helsinki University HospitalHelsinkiFinland
- Aplagon OyHelsinkiFinland
| | - Annukka Jouppila
- Coagulation Disorders UnitHelsinki University Hospital Research InstituteHelsinkiFinland
| | - Alastair J Barr
- Department of Biomedical Science, Faculty of Science & TechnologyUniversity of WestminsterLondonUnited Kingdom
| | - Derek J Ogg
- Peak Proteins LimitedAlderley ParkCheshireUnited Kingdom
| | - Tina D Howard
- Peak Proteins LimitedAlderley ParkCheshireUnited Kingdom
| | | | - Juli Warwicker
- Peak Proteins LimitedAlderley ParkCheshireUnited Kingdom
| | - Catherine Geh
- Peak Proteins LimitedAlderley ParkCheshireUnited Kingdom
| | | | - W Mark Abbott
- Peak Proteins LimitedAlderley ParkCheshireUnited Kingdom
| | - Anita Eckly
- Université de Strasbourg, Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de StrasbourgStrasbourgFrance
| | - Harald Schulze
- Institute of Experimental BiomedicineUniversity Hospital WürzburgWürzburgGermany
| | - Gavin J Wright
- Cell Surface Signalling LaboratoryWellcome Trust Sanger InstituteCambridgeUnited Kingdom
| | - Alexandra Mazharian
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Klaus Fütterer
- School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Sundaresan Rajesh
- Institute of Cancer and Genomic Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Michael R Douglas
- Institute of Inflammation and Ageing, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
- Department of NeurologyDudley Group NHS Foundation TrustDudleyUnited Kingdom
- School of Life and Health SciencesAston UniversityBirminghamUnited Kingdom
| | - Yotis A Senis
- Institute of Cardiovascular Sciences, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
- Université de Strasbourg, Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de StrasbourgStrasbourgFrance
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21
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Jaskiewicz E, Jodłowska M, Kaczmarek R, Zerka A. Erythrocyte glycophorins as receptors for Plasmodium merozoites. Parasit Vectors 2019; 12:317. [PMID: 31234897 PMCID: PMC6591965 DOI: 10.1186/s13071-019-3575-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 06/19/2019] [Indexed: 02/02/2023] Open
Abstract
Glycophorins are heavily glycosylated sialoglycoproteins of human and animal erythrocytes. In humans, there are four glycophorins: A, B, C and D. Glycophorins play an important role in the invasion of red blood cells (RBCs) by malaria parasites, which involves several ligands binding to RBC receptors. Four Plasmodium falciparum merozoite EBL ligands have been identified: erythrocyte-binding antigen-175 (EBA-175), erythrocyte-binding antigen-181 (EBA-181), erythrocyte-binding ligand-1 (EBL-1) and erythrocyte-binding antigen-140 (EBA-140). It is generally accepted that glycophorin A (GPA) is the receptor for P. falciparum EBA-175 ligand. It has been shown that α(2,3) sialic acid residues of GPA O-glycans form conformation-dependent clusters on GPA polypeptide chain which facilitate binding. P. falciparum can also invade erythrocytes using glycophorin B (GPB), which is structurally similar to GPA. It has been shown that P. falciparum EBL-1 ligand binds to GPB. Interestingly, a hybrid GPB-GPA molecule called Dantu is associated with a reduced risk of severe malaria and ameliorates malaria-related morbidity. Glycophorin C (GPC) is a receptor for P. falciparum EBA-140 ligand. Likewise, successful binding of EBA-140 depends on sialic acid residues of N- and O-linked oligosaccharides of GPC, which form a cluster or a conformational structure depending on the presence of peptide fragment encompassing amino acids (aa) 36–63. Evaluation of the homologous P. reichenowi EBA-140 unexpectedly revealed that the chimpanzee homolog of human glycophorin D (GPD) is probably the receptor for this ligand. In this review, we concentrate on the role of glycophorins as erythrocyte receptors for Plasmodium parasites. The presented data support the long-lasting idea of high evolutionary pressure exerted by Plasmodium on the human glycophorins, which emerge as important receptors for these parasites.
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Affiliation(s)
- Ewa Jaskiewicz
- Laboratory of Glikobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland. .,Faculty of Biological Sciences, University of Zielona Góra, Szafrana 1, 65-516, Zielona Góra, Poland.
| | - Marlena Jodłowska
- Laboratory of Glikobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland
| | - Radosław Kaczmarek
- Laboratory of Glikobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland
| | - Agata Zerka
- Laboratory of Glikobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland
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22
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Salinas ND, Tang WK, Tolia NH. Blood-Stage Malaria Parasite Antigens: Structure, Function, and Vaccine Potential. J Mol Biol 2019; 431:4259-4280. [PMID: 31103771 DOI: 10.1016/j.jmb.2019.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/22/2019] [Accepted: 05/08/2019] [Indexed: 10/26/2022]
Abstract
Plasmodium parasites are the causative agent of malaria, a disease that kills approximately 450,000 individuals annually, with the majority of deaths occurring in children under the age of 5 years and the development of a malaria vaccine is a global health priority. Plasmodium parasites undergo a complex life cycle requiring numerous diverse protein families. The blood stage of parasite development results in the clinical manifestation of disease. A vaccine that disrupts the blood stage is highly desired and will aid in the control of malaria. The blood stage comprises multiple steps: invasion of, asexual growth within, and egress from red blood cells. This review focuses on blood-stage antigens with emphasis on antigen structure, antigen function, neutralizing antibodies, and vaccine potential.
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Affiliation(s)
- Nichole D Salinas
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Wai Kwan Tang
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA.
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23
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Deore S, Kumar A, Kumar S, Mittal E, Lotke A, Musti K. Erythrocyte binding ligand region VI specific IgA confers tissue protection in malaria infection. Mol Biol Rep 2019; 46:3801-3808. [DOI: 10.1007/s11033-019-04822-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/13/2019] [Indexed: 11/30/2022]
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24
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Moderately Neutralizing Epitopes in Nonfunctional Regions Dominate the Antibody Response to Plasmodium falciparum EBA-140. Infect Immun 2019; 87:IAI.00716-18. [PMID: 30642904 DOI: 10.1128/iai.00716-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/04/2019] [Indexed: 02/08/2023] Open
Abstract
Plasmodium falciparum erythrocyte-binding antigen 140 (EBA-140) plays a role in tight junction formation during parasite invasion of red blood cells and is a potential vaccine candidate for malaria. Individuals in areas where malaria is endemic possess EBA-140-specific antibodies, and individuals with high antibody titers to this protein have a lower rate of reinfection by parasites. The red blood cell binding segment of EBA-140 is comprised of two Duffy-binding-like domains, called F1 and F2, that together create region II. The sialic acid-binding pocket of F1 is essential for binding, whereas the sialic acid-binding pocket in F2 appears dispensable. Here, we show that immunization of mice with the complete region II results in poorly neutralizing antibodies. In contrast, immunization of mice with the functionally relevant F1 domain of region II results in antibodies that confer a 2-fold increase in parasite neutralization compared to that of the F2 domain. Epitope mapping of diverse F1 and F2 monoclonal antibodies revealed that the functionally relevant F1 sialic acid-binding pocket is a privileged site inaccessible to antibodies, that the F2 sialic acid-binding pocket contains a nonneutralizing epitope, and that two additional epitopes reside in F1 on the opposite face from the sialic acid-binding pocket. These studies indicate that focusing the immune response to the functionally important F1 sialic acid binding pocket improves the protective immune response of EBA-140. These results have implications for improving future vaccine designs and emphasize the importance of structural vaccinology for malaria.
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25
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Paing MM, Salinas ND, Adams Y, Oksman A, Jensen ATR, Goldberg DE, Tolia NH. Shed EBA-175 mediates red blood cell clustering that enhances malaria parasite growth and enables immune evasion. eLife 2018; 7:e43224. [PMID: 30556808 PMCID: PMC6305201 DOI: 10.7554/elife.43224] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/14/2018] [Indexed: 01/22/2023] Open
Abstract
Erythrocyte Binding Antigen of 175 kDa (EBA-175) has a well-defined role in binding to glycophorin A (GpA) during Plasmodium falciparum invasion of erythrocytes. However, EBA-175 is shed post invasion and a role for this shed protein has not been defined. We show that EBA-175 shed from parasites promotes clustering of RBCs, and EBA-175-dependent clusters occur in parasite culture. Region II of EBA-175 is sufficient for clustering RBCs in a GpA-dependent manner. These clusters are capable of forming under physiological flow conditions and across a range of concentrations. EBA-175-dependent RBC clustering provides daughter merozoites ready access to uninfected RBCs enhancing parasite growth. Clustering provides a general method to protect the invasion machinery from immune recognition and disruption as exemplified by protection from neutralizing antibodies that target AMA-1 and RH5. These findings provide a mechanistic framework for the role of shed proteins in RBC clustering, immune evasion, and malaria.
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Affiliation(s)
- May M Paing
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
| | - Nichole D Salinas
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
- Laboratory of Malaria Immunology and VaccinologyNational Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Anna Oksman
- Department of MedicineWashington University School of MedicineSt. LouisUnited States
| | - Anja TR Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Daniel E Goldberg
- Department of MedicineWashington University School of MedicineSt. LouisUnited States
| | - Niraj H Tolia
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
- Laboratory of Malaria Immunology and VaccinologyNational Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
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26
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Silveira ELV, Dominguez MR, Soares IS. To B or Not to B: Understanding B Cell Responses in the Development of Malaria Infection. Front Immunol 2018; 9:2961. [PMID: 30619319 PMCID: PMC6302011 DOI: 10.3389/fimmu.2018.02961] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 12/03/2018] [Indexed: 12/18/2022] Open
Abstract
Malaria is a widespread disease caused mainly by the Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) protozoan parasites. Depending on the parasite responsible for the infection, high morbidity and mortality can be triggered. To escape the host immune responses, Plasmodium parasites disturb the functionality of B cell subsets among other cell types. However, some antibodies elicited during a malaria infection have the potential to block pathogen invasion and dissemination into the host. Thus, the question remains, why is protection not developed and maintained after the primary parasite exposure? In this review, we discuss different aspects of B cell responses against Plasmodium antigens during malaria infection. Since most studies have focused on the quantification of serum antibody titers, those B cell responses have not been fully characterized. However, to secrete antibodies, a complex cellular response is set up, including not only the activation and differentiation of B cells into antibody-secreting cells, but also the participation of other cell subsets in the germinal center reactions. Therefore, a better understanding of how B cell subsets are stimulated during malaria infection will provide essential insights toward the design of potent interventions.
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Affiliation(s)
- Eduardo L V Silveira
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mariana R Dominguez
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Irene S Soares
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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27
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Lennartz F, Brod F, Dabbs R, Miura K, Mekhaiel D, Marini A, Jore MM, Søgaard MM, Jørgensen T, de Jongh WA, Sauerwein RW, Long CA, Biswas S, Higgins MK. Structural basis for recognition of the malaria vaccine candidate Pfs48/45 by a transmission blocking antibody. Nat Commun 2018; 9:3822. [PMID: 30237518 PMCID: PMC6148045 DOI: 10.1038/s41467-018-06340-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022] Open
Abstract
The quest to develop an effective malaria vaccine remains a major priority in the fight against global infectious disease. An approach with great potential is a transmission-blocking vaccine which induces antibodies that prevent establishment of a productive infection in mosquitos that feed on infected humans, thereby stopping the transmission cycle. One of the most promising targets for such a vaccine is the gamete surface protein, Pfs48/45. Here we establish a system for production of full-length Pfs48/45 and use this to raise a panel of monoclonal antibodies. We map the binding regions of these antibodies on Pfs48/45 and correlate the location of their epitopes with their transmission-blocking activity. Finally, we present the structure of the C-terminal domain of Pfs48/45 bound to the most potent transmission-blocking antibody, and provide key molecular information for future structure-guided immunogen design. Pfs48/45 is a promising component for a transmission-blocking malaria vaccine. Here, the authors develop a system to produce full-length Pfs48/45 for immunisation, characterise a panel of monoclonal antibodies and determine the structure of a potent transmission-blocking epitope.
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Florian Brod
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Rebecca Dabbs
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - David Mekhaiel
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Arianna Marini
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Max M Søgaard
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Thomas Jørgensen
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Willem A de Jongh
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Carole A Long
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - Sumi Biswas
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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28
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Abstract
Humoral immune responses against the malaria parasite are an important component of a protective immune response. Antibodies are often directed towards conformational epitopes, and the native structure of the antigenic region is usually critical for antibody recognition. We examined the structural features of various Plasmodium antigens that may impact on epitope location, by performing a comprehensive analysis of known and modelled structures from P. falciparum. Examining the location of known polymorphisms over all available structures, we observed a strong propensity for polymorphic residues to be exposed on the surface and to occur in particular secondary structure segments such as hydrogen-bonded turns. We also utilised established prediction algorithms for B-cell epitopes and MHC class II binding peptides, examining predicted epitopes in relation to known polymorphic sites within structured regions. Finally, we used the available structures to examine polymorphic hotspots and Tajima's D values using a spatial averaging approach. We identified a region of PfAMA1 involving both domains II and III under a high degree of balancing selection relative to the rest of the protein. In summary, we developed general methods for examining how sequence-based features relate to one another in three-dimensional space and applied these methods to key P. falciparum antigens.
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29
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Abagna HB, Acquah FK, Okonu R, Aryee NA, Theisen M, Amoah LE. Assessment of the quality and quantity of naturally induced antibody responses to EBA175RIII-V in Ghanaian children living in two communities with varying malaria transmission patterns. Malar J 2018; 17:14. [PMID: 29310662 PMCID: PMC5759240 DOI: 10.1186/s12936-017-2167-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/29/2017] [Indexed: 01/26/2023] Open
Abstract
Background Recent global reports on malaria suggest significant decrease in disease severity and an increase in control interventions in many malaria endemic countries, including Ghana. However, a major driving force sustaining malaria transmission in recent times is the asymptomatic carriage of malaria parasites, which can enhance immune responses against parasite antigens. This study determined the prevalence and relative avidities of naturally induced antibodies to EBA175RIII–VLl in asymptomatic children living in two communities with varying malaria transmission patterns. Methods An asexual stage Plasmodium falciparum antigen, EBA175RIII–VLl was expressed in Lactococcus lactis, purified and used in indirect ELISA to measure total and cytophilic IgG concentrations and avidities in children aged between 6 and 12 years. The children were selected from Obom and Abura, communities with perennial and seasonal malaria transmission, respectively. Venous blood samples were collected in July and October 2015 and again in January 2016. The multiplicity of infection and the genetic diversity of EBA175RIII circulating in both sites were also assessed using polymerase chain reaction. Results Asymptomatic parasite carriage in the children from Obom decreased from July (peak season), through October and January, however parasite carriage in children from Abura was bimodal, with the lowest prevalence estimated in October. Antibody concentrations over the course of the study remained stable within each study site however, children living in Obom had significantly higher EBA175RIII–VLl antibody concentrations than children living in Abura (P < 0.05, Mann–Whitney test). Over the course of the study, the relative antibody avidities of EBA175RIII–VLl IgG antibodies were similar within and between the sites. Conclusion Naturally acquired IgG concentrations but not relative antibody avidities to EBA175RIII–V were significantly higher in Obom where malaria transmission is perennial than in Abura, where malaria transmission is seasonal. Electronic supplementary material The online version of this article (10.1186/s12936-017-2167-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hamza B Abagna
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.,Department of Medical Biochemistry, University of Ghana, Accra, Ghana
| | - Festus K Acquah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Ruth Okonu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Nii A Aryee
- Department of Medical Biochemistry, University of Ghana, Accra, Ghana
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Linda E Amoah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
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30
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Kumar K, Srinivasan P, Nold MJ, Moch JK, Reiter K, Sturdevant D, Otto TD, Squires RB, Herrera R, Nagarajan V, Rayner JC, Porcella SF, Geromanos SJ, Haynes JD, Narum DL. Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach. Sci Rep 2017; 7:17146. [PMID: 29215067 PMCID: PMC5719419 DOI: 10.1038/s41598-017-17505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10-300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion.
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Affiliation(s)
- Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, USA.
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - J Kathleen Moch
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Dan Sturdevant
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - R Burke Squires
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Vijayaraj Nagarajan
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | | | - J David Haynes
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA.
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31
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Chowdhury P, Sen S, Kanjilal SD, Sengupta S. Genetic structure of two erythrocyte binding antigens of Plasmodium falciparum reveals a contrasting pattern of selection. INFECTION GENETICS AND EVOLUTION 2017; 57:64-74. [PMID: 29128519 DOI: 10.1016/j.meegid.2017.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/18/2017] [Accepted: 11/07/2017] [Indexed: 11/15/2022]
Abstract
Erythrocyte binding antigens 175 (EBA-175) and 140 (EBA-140) play key roles in erythrocyte invasion by binding to glycophorin A (GPA) and C (GPC) respectively in human malaria. Since antigenic variation in malaria endemic region is a major barrier to development of effective vaccine, we explore the nature and pattern of sequence diversity of these two vaccine candidates in Kolkata, India. Population genetic parameters based on parasite sequences representing region II of Pfeba-175 and Pfeba-140 genes were estimated using DnaSP V.5.10 and MEGA version 6.0. A novel molecular docking approach was implemented to assess the binding affinities of Kolkata Pfeba-175 variants with GPA. P. falciparum Kolkata isolates experienced a recent population expansion as documented by negative Tajima's D, Fu & Li's statistics, unimodal mismatch distribution and star-like median-joining network for both loci. Positive selection seemed to play a major role in shaping the diversity of Pfeba-175 (dN/dS=2.45, and McDonald-Kreitman P-value=0.04) with successive accumulation of Q584K/E, E592A and R664S deriving high frequency haplotypes designated here as F2KH3 and F2KH1. In silico molecular docking demonstrated that polypeptides encoded by F2KH1 and F2KH3 were capable of engaging the parasite ligand into energetically favorable interaction with GPA. Our data demonstrated emergence of Pfeba-175 sequences harboring selectively advantageous nonsynonymous substitutions on Pf3D7 sequence background in the Kolkata parasite isolates. A contrasting pattern of Pf3D7-centric expansion of parasite sequences was noted for Pfeba-140. Together, this study provides a firm genetic and biological support favoring a dominant role of EBA-175 in erythrocyte invasion.
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Affiliation(s)
- Pramita Chowdhury
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Srikanta Sen
- Mitra Tower, Lake Town, Block-A, Kolkata 700 089, India
| | - Sumana Datta Kanjilal
- Department of Pediatric Medicine, Institute of Post Graduate Medical Education & Research, Kolkata, West Bengal, India
| | - Sanghamitra Sengupta
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700 019, West Bengal, India.
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32
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Abstract
Basic science holds enormous power for revealing the biological mechanisms of disease and, in turn, paving the way toward new, effective interventions. Recognizing this power, the 2011 Research Agenda for Malaria Eradication included key priorities in fundamental research that, if attained, could help accelerate progress toward disease elimination and eradication. The Malaria Eradication Research Agenda (malERA) Consultative Panel on Basic Science and Enabling Technologies reviewed the progress, continuing challenges, and major opportunities for future research. The recommendations come from a literature of published and unpublished materials and the deliberations of the malERA Refresh Consultative Panel. These areas span multiple aspects of the Plasmodium life cycle in both the human host and the Anopheles vector and include critical, unanswered questions about parasite transmission, human infection in the liver, asexual-stage biology, and malaria persistence. We believe an integrated approach encompassing human immunology, parasitology, and entomology, and harnessing new and emerging biomedical technologies offers the best path toward addressing these questions and, ultimately, lowering the worldwide burden of malaria.
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Plasmodium falciparum erythrocyte-binding antigen 175 triggers a biophysical change in the red blood cell that facilitates invasion. Proc Natl Acad Sci U S A 2017; 114:4225-4230. [PMID: 28373555 DOI: 10.1073/pnas.1620843114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Invasion of the red blood cell (RBC) by the Plasmodium parasite defines the start of malaria disease pathogenesis. To date, experimental investigations into invasion have focused predominantly on the role of parasite adhesins or signaling pathways and the identity of binding receptors on the red cell surface. A potential role for signaling pathways within the erythrocyte, which might alter red cell biophysical properties to facilitate invasion, has largely been ignored. The parasite erythrocyte-binding antigen 175 (EBA175), a protein required for entry in most parasite strains, plays a key role by binding to glycophorin A (GPA) on the red cell surface, although the function of this binding interaction is unknown. Here, using real-time deformability cytometry and flicker spectroscopy to define biophysical properties of the erythrocyte, we show that EBA175 binding to GPA leads to an increase in the cytoskeletal tension of the red cell and a reduction in the bending modulus of the cell's membrane. We isolate the changes in the cytoskeleton and membrane and show that reduction in the bending modulus is directly correlated with parasite invasion efficiency. These data strongly imply that the malaria parasite primes the erythrocyte surface through its binding antigens, altering the biophysical nature of the target cell and thus reducing a critical energy barrier to invasion. This finding would constitute a major change in our concept of malaria parasite invasion, suggesting it is, in fact, a balance between parasite and host cell physical forces working together to facilitate entry.
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Sisquella X, Nebl T, Thompson JK, Whitehead L, Malpede BM, Salinas ND, Rogers K, Tolia NH, Fleig A, O'Neill J, Tham WH, David Horgen F, Cowman AF. Plasmodium falciparum ligand binding to erythrocytes induce alterations in deformability essential for invasion. eLife 2017; 6. [PMID: 28226242 PMCID: PMC5333951 DOI: 10.7554/elife.21083] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/09/2017] [Indexed: 12/31/2022] Open
Abstract
The most lethal form of malaria in humans is caused by Plasmodium falciparum. These parasites invade erythrocytes, a complex process involving multiple ligand-receptor interactions. The parasite makes initial contact with the erythrocyte followed by dramatic deformations linked to the function of the Erythrocyte binding antigen family and P. falciparum reticulocyte binding-like families. We show EBA-175 mediates substantial changes in the deformability of erythrocytes by binding to glycophorin A and activating a phosphorylation cascade that includes erythrocyte cytoskeletal proteins resulting in changes in the viscoelastic properties of the host cell. TRPM7 kinase inhibitors FTY720 and waixenicin A block the changes in the deformability of erythrocytes and inhibit merozoite invasion by directly inhibiting the phosphorylation cascade. Therefore, binding of P. falciparum parasites to the erythrocyte directly activate a signaling pathway through a phosphorylation cascade and this alters the viscoelastic properties of the host membrane conditioning it for successful invasion.
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Affiliation(s)
- Xavier Sisquella
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Thomas Nebl
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Brian M Malpede
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Nichole D Salinas
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Kelly Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Niraj H Tolia
- Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, United States.,Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, United States
| | - Andrea Fleig
- The Queen's Medical Center and John A. Burns School of Medicine, University of Hawaii, Honolulu, United States
| | - Joseph O'Neill
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, United States
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Australia
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Abstract
PURPOSE OF REVIEW Red cell receptors provide unique entry points for Plasmodium parasites to initiate blood-stage malaria infection. Parasites encode distinct ligands that bind specifically to both highly abundant and low-copy receptors. Recent advances in the understanding of molecular and structural mechanisms of these interactions provide fundamental insights into receptor-ligand biology and molecular targets for intervention. RECENT FINDINGS The review focuses on the requirements for known interactions, insight derived from complex structures, and mechanisms of receptor/ligand engagement. Further, novel roles for established red cell membrane proteins, parasite ligands and associated interacting partners have recently been established in red cell invasion. SUMMARY The new knowledge underlines the intricacies involved in invasion by a eukaryotic parasite into a eukaryotic host cell demonstrated by expanded parasite ligand families, redundancy in red cell receptor engagement, multitiered temporal binding, and the breadth of receptors engaged.
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Jimah JR, Salinas ND, Sala-Rabanal M, Jones NG, Sibley LD, Nichols CG, Schlesinger PH, Tolia NH. Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption. eLife 2016; 5. [PMID: 27906127 PMCID: PMC5132341 DOI: 10.7554/elife.20621] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/14/2016] [Indexed: 01/02/2023] Open
Abstract
Apicomplexan parasites contain a conserved protein CelTOS that, in malaria parasites, is essential for traversal of cells within the mammalian host and arthropod vector. However, the molecular role of CelTOS is unknown because it lacks sequence similarity to proteins of known function. Here, we determined the crystal structure of CelTOS and discovered CelTOS resembles proteins that bind to and disrupt membranes. In contrast to known membrane disruptors, CelTOS has a distinct architecture, specifically binds phosphatidic acid commonly present within the inner leaflet of plasma membranes, and potently disrupts liposomes composed of phosphatidic acid by forming pores. Microinjection of CelTOS into cells resulted in observable membrane damage. Therefore, CelTOS is unique as it achieves nearly universal inner leaflet cellular activity to enable the exit of parasites from cells during traversal. By providing novel molecular insight into cell traversal by apicomplexan parasites, our work facilitates the design of therapeutics against global pathogens.
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Affiliation(s)
- John R Jimah
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Monica Sala-Rabanal
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Paul H Schlesinger
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, United States
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37
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Chen E, Salinas ND, Huang Y, Ntumngia F, Plasencia MD, Gross ML, Adams JH, Tolia NH. Broadly neutralizing epitopes in the Plasmodium vivax vaccine candidate Duffy Binding Protein. Proc Natl Acad Sci U S A 2016; 113:6277-82. [PMID: 27194724 PMCID: PMC4896725 DOI: 10.1073/pnas.1600488113] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plasmodium vivax Duffy Binding Protein (PvDBP) is the most promising vaccine candidate for P. vivax malaria. The polymorphic nature of PvDBP induces strain-specific immune responses, however, and the epitopes of broadly neutralizing antibodies are unknown. These features hamper the rational design of potent DBP-based vaccines and necessitate the identification of globally conserved epitopes. Using X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange mass spectrometry, and mutational mapping, we have defined epitopes for three inhibitory mAbs (mAbs 2D10, 2H2, and 2C6) and one noninhibitory mAb (3D10) that engage DBP. These studies expand the currently known inhibitory epitope repertoire by establishing protective motifs in subdomain three outside the receptor-binding and dimerization residues of DBP, and introduce globally conserved protective targets. All of the epitopes are highly conserved among DBP alleles. The identification of broadly conserved epitopes of inhibitory antibodies provides critical motifs that should be retained in the next generation of potent vaccines for P. vivax malaria.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing/immunology
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Crystallography, X-Ray
- Enzyme-Linked Immunosorbent Assay
- Epitopes, B-Lymphocyte/immunology
- Erythrocytes/immunology
- Erythrocytes/parasitology
- Erythrocytes/pathology
- Genetic Variation
- Humans
- Malaria Vaccines/immunology
- Malaria Vaccines/therapeutic use
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Models, Molecular
- Plasmodium vivax/genetics
- Plasmodium vivax/immunology
- Protein Binding
- Protein Conformation
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
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Affiliation(s)
- Edwin Chen
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Yining Huang
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Francis Ntumngia
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL 33620
| | - Manolo D Plasencia
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Michael L Gross
- Department of Chemistry, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - John H Adams
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL 33620
| | - Niraj Harish Tolia
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
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38
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Chiu CY, White MT, Healer J, Thompson JK, Siba PM, Mueller I, Cowman AF, Hansen DS. Different Regions of Plasmodium falciparum Erythrocyte-Binding Antigen 175 Induce Antibody Responses to Infection of Varied Efficacy. J Infect Dis 2016; 214:96-104. [PMID: 27020092 DOI: 10.1093/infdis/jiw119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/18/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Increasing evidence suggests that antibodies against merozoite proteins involved in Plasmodium falciparum invasion into the red blood cell play an important role in clinical immunity to malaria. Erythrocyte-binding antigen 175 (EBA-175) is the best-characterized P. falciparum invasion ligand, reported to recognize glycophorin A on the surface of erythrocytes. Its protein structure comprises 6 extracellular regions. Whereas region II contains Duffy binding-like domains involved in the binding to glycophorin A, the functional role of regions III-V is less clear. METHODS We developed a novel cytometric bead array for assessment of antigen-specific antibody concentration in plasma to evaluate the efficacy of immune responses to different regions of EBA-175 and associations between antibody levels with protection from symptomatic malaria in a treatment-reinfection cohort study. RESULTS We found that while antibodies to region II are highly abundant, circulating levels as low as 5-10 µg/mL of antibodies specific for region III or the highly conserved regions IV-V predict strong protection from clinical malaria. CONCLUSIONS These results lend support for the development of conserved regions of EBA-175 as components in a combination of a malaria vaccine.
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Affiliation(s)
- Chris Y Chiu
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael T White
- The Walter and Eliza Hall Institute of Medical Research MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, United Kingdom
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Jenny K Thompson
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Peter M Siba
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Goroka, Eastern Highlands Province
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Diana S Hansen
- The Walter and Eliza Hall Institute of Medical Research Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
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Structural Basis for Recognition of Human Enterovirus 71 by a Bivalent Broadly Neutralizing Monoclonal Antibody. PLoS Pathog 2016; 12:e1005454. [PMID: 26938634 PMCID: PMC4777393 DOI: 10.1371/journal.ppat.1005454] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/23/2016] [Indexed: 02/01/2023] Open
Abstract
Enterovirus 71 (EV71) is the main pathogen responsible for hand, foot and mouth disease with severe neurological complications and even death in young children. We have recently identified a highly potent anti-EV71 neutralizing monoclonal antibody, termed D5. Here we investigated the structural basis for recognition of EV71 by the antibody D5. Four three-dimensional structures of EV71 particles in complex with IgG or Fab of D5 were reconstructed by cryo-electron microscopy (cryo-EM) single particle analysis all at subnanometer resolutions. The most critical EV71 mature virion-Fab structure was resolved to a resolution of 4.8 Å, which is rare in cryo-EM studies of virus-antibody complex so far. The structures reveal a bivalent binding pattern of D5 antibody across the icosahedral 2-fold axis on mature virion, suggesting that D5 binding may rigidify virions to prevent their conformational changes required for subsequent RNA release. Moreover, we also identified that the complementary determining region 3 (CDR3) of D5 heavy chain directly interacts with the extremely conserved VP1 GH-loop of EV71, which was validated by biochemical and virological assays. We further showed that D5 is indeed able to neutralize a variety of EV71 genotypes and strains. Moreover, D5 could potently confer protection in a mouse model of EV71 infection. Since the conserved VP1 GH-loop is involved in EV71 binding with its uncoating receptor, the scavenger receptor class B, member 2 (SCARB2), the broadly neutralizing ability of D5 might attribute to its inhibition of EV71 from binding SCARB2. Altogether, our results elucidate the structural basis for the binding and neutralization of EV71 by the broadly neutralizing antibody D5, thereby enhancing our understanding of antibody-based protection against EV71 infection.
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40
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Hostetler JB, Sharma S, Bartholdson SJ, Wright GJ, Fairhurst RM, Rayner JC. A Library of Plasmodium vivax Recombinant Merozoite Proteins Reveals New Vaccine Candidates and Protein-Protein Interactions. PLoS Negl Trop Dis 2015; 9:e0004264. [PMID: 26701602 PMCID: PMC4689532 DOI: 10.1371/journal.pntd.0004264] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 11/05/2015] [Indexed: 11/27/2022] Open
Abstract
Background A vaccine targeting Plasmodium vivax will be an essential component of any comprehensive malaria elimination program, but major gaps in our understanding of P. vivax biology, including the protein-protein interactions that mediate merozoite invasion of reticulocytes, hinder the search for candidate antigens. Only one ligand-receptor interaction has been identified, that between P. vivax Duffy Binding Protein (PvDBP) and the erythrocyte Duffy Antigen Receptor for Chemokines (DARC), and strain-specific immune responses to PvDBP make it a complex vaccine target. To broaden the repertoire of potential P. vivax merozoite-stage vaccine targets, we exploited a recent breakthrough in expressing full-length ectodomains of Plasmodium proteins in a functionally-active form in mammalian cells and initiated a large-scale study of P. vivax merozoite proteins that are potentially involved in reticulocyte binding and invasion. Methodology/Principal Findings We selected 39 P. vivax proteins that are predicted to localize to the merozoite surface or invasive secretory organelles, some of which show homology to P. falciparum vaccine candidates. Of these, we were able to express 37 full-length protein ectodomains in a mammalian expression system, which has been previously used to express P. falciparum invasion ligands such as PfRH5. To establish whether the expressed proteins were correctly folded, we assessed whether they were recognized by antibodies from Cambodian patients with acute vivax malaria. IgG from these samples showed at least a two-fold change in reactivity over naïve controls in 27 of 34 antigens tested, and the majority showed heat-labile IgG immunoreactivity, suggesting the presence of conformation-sensitive epitopes and native tertiary protein structures. Using a method specifically designed to detect low-affinity, extracellular protein-protein interactions, we confirmed a predicted interaction between P. vivax 6-cysteine proteins P12 and P41, further suggesting that the proteins are natively folded and functional. This screen also identified two novel protein-protein interactions, between P12 and PVX_110945, and between MSP3.10 and MSP7.1, the latter of which was confirmed by surface plasmon resonance. Conclusions/Significance We produced a new library of recombinant full-length P. vivax ectodomains, established that the majority of them contain tertiary structure, and used them to identify predicted and novel protein-protein interactions. As well as identifying new interactions for further biological studies, this library will be useful in identifying P. vivax proteins with vaccine potential, and studying P. vivax malaria pathogenesis and immunity. Trial Registration ClinicalTrials.gov NCT00663546 Plasmodium vivax causes malaria in millions of people each year, primarily in Southeast Asia and Central and South America. P. vivax has a dormant liver stage, which can lead to disease recurrence in infected individuals even in the absence of mosquito transmission. The development of vaccines that target blood-stage P. vivax parasites is therefore likely to be an essential component of any worldwide effort to eradicate malaria. Studying P. vivax is very difficult as this parasite grows poorly in the laboratory and invades only small numbers of young red blood cells in patients. Due to these and other challenges, only a handful of P. vivax proteins have been tested as potential vaccines. To generate more vaccine candidates, we expressed the entire ectodomains of 37 proteins that are predicted to be involved in P. vivax invasion of red blood cells. Antibodies from Cambodian patients with P. vivax malaria recognized heat-sensitive epitopes in the majority of these proteins, suggesting that they are natively folded. We also used the proteins to screen for both predicted and novel protein-protein interactions, confirming that the proteins are functional and further supporting their potential as vaccine candidates. As a new community resource, this P. vivax recombinant protein library will facilitate future studies of P. vivax pathogenesis and immunity, and greatly expands the list of candidate vaccine antigens.
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Affiliation(s)
- Jessica B. Hostetler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Sumana Sharma
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - S. Josefin Bartholdson
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Gavin J. Wright
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (RMF); (JCR)
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- * E-mail: (RMF); (JCR)
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41
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Singh B, Gupta PK, Chauhan V, Chitnis C. Novel and cost-effective refolding of a recombinant receptor binding domain of Plasmodium falciparum EBA-175. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.09.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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42
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Irani V, Ramsland PA, Guy AJ, Siba PM, Mueller I, Richards JS, Beeson JG. Acquisition of Functional Antibodies That Block the Binding of Erythrocyte-Binding Antigen 175 and Protection Against Plasmodium falciparum Malaria in Children. Clin Infect Dis 2015; 61:1244-52. [PMID: 26136391 DOI: 10.1093/cid/civ525] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/22/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The targets and mechanisms of human immunity to malaria are poorly understood, which poses a major barrier to malaria vaccine development. Antibodies play a key role in human immunity and may act by inhibiting receptor-binding functions of key merozoite invasion ligands. Antibodies to the major invasion ligand and vaccine candidate, erythrocyte-binding antigen 175 (EBA-175), have been linked with protection, but how these antibodies function has not been established. METHODS We developed 2 new assays that quantify the ability of antibodies to inhibit binding of EBA-175 to its erythrocyte receptor, glycophorin A, using either native or recombinant EBA-175. Binding-inhibitory antibodies were evaluated in a longitudinal cohort study of Papua New Guinean children and related to risk of malaria, age, infection status, and markers of parasite exposure. RESULTS Binding-inhibition assays (BIAs) were reproducible, and the 2 assays had a high level of agreement. Inhibitory antibodies were common among children, acquired in association with markers of increasing parasite exposure, and high in those children with active infection. Inhibitory antibodies correlated with total immunoglobulin G levels to the EBA-175 binding domain (region II). Importantly, binding-inhibitory antibodies were significantly associated with protection from symptomatic malaria when measured using either BIA. CONCLUSIONS Findings suggest that naturally acquired binding-inhibitory antibodies are an important functional mechanism that contributes to protection against malaria and further supports the potential of EBA-175 as a vaccine candidate. Identifying vaccines and approaches that induce potent binding-inhibitory antibodies may be a valuable strategy in the development of highly efficacious malaria vaccines.
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Affiliation(s)
- Vashti Irani
- Centre for Biomedical Research, Burnet Institute, Melbourne Department of Medicine, University of Melbourne, Parkville Department of Immunology, Monash University, Melbourne
| | - Paul A Ramsland
- Centre for Biomedical Research, Burnet Institute, Melbourne Department of Immunology, Monash University, Melbourne Department of Surgery, Austin Health, University of Melbourne, Heidelberg, Victoria School of Biomedical Sciences, Curtin Health Innovation Research Institute-Biosciences, Curtin University, Perth, Western Australia, Australia
| | - Andrew J Guy
- Centre for Biomedical Research, Burnet Institute, Melbourne Department of Immunology, Monash University, Melbourne
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia Barcelona Centre for International Health Research, Spain
| | - Jack S Richards
- Centre for Biomedical Research, Burnet Institute, Melbourne Department of Medicine, University of Melbourne, Parkville Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - James G Beeson
- Centre for Biomedical Research, Burnet Institute, Melbourne Department of Medicine, University of Melbourne, Parkville Department of Microbiology, Monash University, Clayton, Victoria, Australia
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Boucher LE, Bosch J. The apicomplexan glideosome and adhesins - Structures and function. J Struct Biol 2015; 190:93-114. [PMID: 25764948 PMCID: PMC4417069 DOI: 10.1016/j.jsb.2015.02.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 02/20/2015] [Accepted: 02/26/2015] [Indexed: 01/10/2023]
Abstract
The apicomplexan family of pathogens, which includes Plasmodium spp. and Toxoplasma gondii, are primarily obligate intracellular parasites and invade multiple cell types. These parasites express extracellular membrane protein receptors, adhesins, to form specific pathogen-host cell interaction complexes. Various adhesins are used to invade a variety of cell types. The receptors are linked to an actomyosin motor, which is part of a complex comprised of many proteins known as the invasion machinery or glideosome. To date, reviews on invasion have focused primarily on the molecular pathways and signals of invasion, with little or no structural information presented. Over 75 structures of parasite receptors and glideosome proteins have been deposited with the Protein Data Bank. These structures include adhesins, motor proteins, bridging proteins, inner membrane complex and cytoskeletal proteins, as well as co-crystal structures with peptides and antibodies. These structures provide information regarding key interactions necessary for target receptor engagement, machinery complex formation, how force is transmitted, and the basis of inhibitory antibodies. Additionally, these structures can provide starting points for the development of antibodies and inhibitory molecules targeting protein-protein interactions, with the aim to inhibit invasion. This review provides an overview of the parasite adhesin protein families, the glideosome components, glideosome architecture, and discuss recent work regarding alternative models.
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Affiliation(s)
- Lauren E Boucher
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA; Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA.
| | - Jürgen Bosch
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA; Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA.
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Structural analysis of the synthetic Duffy Binding Protein (DBP) antigen DEKnull relevant for Plasmodium vivax malaria vaccine design. PLoS Negl Trop Dis 2015; 9:e0003644. [PMID: 25793371 PMCID: PMC4368114 DOI: 10.1371/journal.pntd.0003644] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/24/2015] [Indexed: 01/03/2023] Open
Abstract
The Plasmodium vivax vaccine candidate Duffy Binding Protein (DBP) is a protein necessary for P. vivax invasion of reticulocytes. The polymorphic nature of DBP induces strain-specific immune responses that pose unique challenges for vaccine development. DEKnull is a synthetic DBP based antigen that has been engineered through mutation to enhance induction of blocking inhibitory antibodies. We determined the x-ray crystal structure of DEKnull to identify if any conformational changes had occurred upon mutation. Computational and experimental analyses assessed immunogenicity differences between DBP and DEKnull epitopes. Functional binding assays with monoclonal antibodies were used to interrogate the available epitopes in DEKnull. We demonstrate that DEKnull is structurally similar to the parental Sal1 DBP. The DEKnull mutations do not cause peptide backbone shifts within the polymorphic loop, or at either the DBP dimerization interface or DARC receptor binding pockets, two important structurally conserved protective epitope motifs. All B-cell epitopes, except for the mutated DEK motif, are conserved between DEKnull and DBP. The DEKnull protein retains binding to conformationally dependent inhibitory antibodies. DEKnull is an iterative improvement of DBP as a vaccine candidate. DEKnull has reduced immunogenicity to polymorphic regions responsible for strain-specific immunity while retaining conserved protein folds necessary for induction of strain-transcending blocking inhibitory antibodies. Plasmodium vivax is an oft neglected causative agent of human malaria. It inflicts tremendous burdens on public health infrastructures and causes significant detrimental effects on socio-economic growth throughout the world. P. vivax Duffy Binding Protein (DBP) is a surface protein that the parasite uses to invade host red blood cells and is a leading vaccine candidate. The variable nature of DBP poses unique challenges in creating an all-encompassing generalized vaccine. One method to circumvent this problem is to synthetically engineer a single artificial protein antigen that has reduced variability while maintaining conserved protective motifs to elicit strain-transcending protection. This synthetic antigen is termed DEKnull. Here, we provide structural and biochemical evidence that DEKnull was successfully engineered to eliminate polymorphic epitopes while retaining the overall fold of the protein, including conserved conformational protective epitopes. Our work presents validation for an improved iteration of the DBP P. vivax vaccine candidate, and provides evidence that protein engineering is successful in countering DBP polymorphisms. In doing so, we also lay down the foundation that engineering synthetic antigens is a viable approach and should be considered in future vaccine designs for pathogens.
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Saetear P, Perrin AJ, Bartholdson SJ, Wanaguru M, Kussrow A, Bornhop DJ, Wright GJ. Quantification of Plasmodium-host protein interactions on intact, unmodified erythrocytes by back-scattering interferometry. Malar J 2015; 14:88. [PMID: 25889240 PMCID: PMC4349660 DOI: 10.1186/s12936-015-0553-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/06/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Invasion of host erythrocytes by Plasmodium falciparum is central to the pathogenesis of malaria. Invasion involves recognition events between erythrocyte receptors and ligands on the merozoite, the invasive blood form of the parasite. Identifying and characterizing host-parasite interactions is impeded by the biochemical challenges of working with membrane-embedded glycoprotein receptors. For example, the interaction between P. falciparum erythrocyte binding antigen 175 (PfEBA175) and glycophorin A (GYPA) depends on post-translational modifications that are not easily added in recombinant expression systems, and the use of native GYPA is limited by the hydrophobic transmembrane region, making it difficult to biochemically manipulate. It would, therefore, be desirable to perform quantitative binding assays with receptors embedded within the membranes of intact human erythrocytes. METHODS The extracellular region of GYPA was over-expressed as a soluble protein in HEK293E cells. This protein was characterized, sialylated and evaluated for binding to the PfEBA175 protein. The label-free and free-solution assay, backscattering interferometry (BSI), was used to perform binding assays of two well-characterized P. falciparum invasion ligands to intact unmodified human erythrocytes. RESULTS Findings indicate that the post-translational modifications present on native GYPA are required for it to bind recombinant PfEBA175 and that these modifications cannot be recapitulated in vitro using mammalian overexpression methods. Here, BSI was used to obtain quantitative, high fidelity interaction determinations on intact, unmodified erythrocytes. Using BSI and purified recombinant proteins constituting the entire ectodomains of the P. falciparum merozoite ligands PfEBA175 and PfRH5, K Ds of 1.1 μM and 50 nM were measured for the PfRH5-BSG and PfEBA175-GYPA interactions, respectively, in good agreement with previous biophysical measurements of these interactions. CONCLUSIONS These results demonstrate that BSI can be used to detect and quantify the interactions of two merozoite invasion ligands with their receptors on intact human erythrocytes. BSI assays were performed on unlabelled, free-solution proteins in their native environment, requiring only nanomoles of recombinant protein. This study suggests that BSI can be used to investigate host-parasite protein interactions without the limitations of other assay platforms, and therefore represents a valuable new method to investigate the molecular mechanisms involved in erythrocyte invasion by P. falciparum.
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Affiliation(s)
- Phoonthawee Saetear
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand.
| | - Abigail J Perrin
- Cell Surface Signalling Laboratory and Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
| | - S Josefin Bartholdson
- Cell Surface Signalling Laboratory and Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
| | - Madushi Wanaguru
- Cell Surface Signalling Laboratory and Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
| | - Amanda Kussrow
- Department of Chemistry and the Vanderbilt Institute for Chemical Biology, Vanderbilt University, 4226 Stevenson Center, Nashville, Tennessee, 37235, USA.
| | - Darryl J Bornhop
- Department of Chemistry and the Vanderbilt Institute for Chemical Biology, Vanderbilt University, 4226 Stevenson Center, Nashville, Tennessee, 37235, USA.
| | - Gavin J Wright
- Cell Surface Signalling Laboratory and Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
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Critical glycosylated residues in exon three of erythrocyte glycophorin A engage Plasmodium falciparum EBA-175 and define receptor specificity. mBio 2014; 5:e01606-14. [PMID: 25205096 PMCID: PMC4173783 DOI: 10.1128/mbio.01606-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Erythrocyte invasion is an essential step in the pathogenesis of malaria. The erythrocyte binding-like (EBL) family of Plasmodium falciparum proteins recognizes glycophorins (Gp) on erythrocytes and plays a critical role in attachment during invasion. However, the molecular basis for specific receptor recognition by each parasite ligand has remained elusive, as is the case with the ligand/receptor pair P. falciparum EBA-175 (PfEBA-175)/GpA. This is due largely to difficulties in producing properly glycosylated and functional receptors. Here, we developed an expression system to produce recombinant glycosylated and functional GpA, as well as mutations and truncations. We identified the essential binding region and determinants for PfEBA-175 engagement, demonstrated that these determinants are required for the inhibition of parasite growth, and identified the glycans important in mediating the PfEBA-175–GpA interaction. The results suggest that PfEBA-175 engages multiple glycans of GpA encoded by exon 3 and that the presentation of glycans is likely required for high-avidity binding. The absence of exon 3 in GpB and GpE due to a splice site mutation confers specific recognition of GpA by PfEBA-175. We speculate that GpB and GpE may have arisen due to selective pressure to lose the PfEBA-175 binding site in GpA. The expression system described here has wider application for examining other EBL members important in parasite invasion, as well as additional pathogens that recognize glycophorins. The ability to define critical binding determinants in receptor-ligand interactions, as well as a system to genetically manipulate glycosylated receptors, opens new avenues for the design of interventions that disrupt parasite invasion. Plasmodium falciparum uses distinct ligands that bind host cell receptors for invasion of red blood cells (RBCs) during malaria infection. A key entry pathway involves P. falciparum EBA-175 (PfEBA-175) recognizing glycophorin A (GpA) on RBCs. Despite knowledge of this protein-protein interaction, the complete mechanism for specific receptor engagement is not known. PfEBA-175 recognizes GpA but is unable to engage the related RBC receptor GpB or GpE. Understanding the necessary elements that enable PfEBA-175 to specifically recognize GpA is critical in developing specific and potent inhibitors of PfEBA-175 that disrupt host cell invasion and aid in malaria control. Here, we describe a novel system to produce and manipulate the host receptor GpA. Using this system, we probed the elements in GpA necessary for engagement and thus for host cell invasion. These studies have important implications for understanding how ligands and receptors interact and for the future development of malaria interventions.
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Paing MM, Tolia NH. Multimeric assembly of host-pathogen adhesion complexes involved in apicomplexan invasion. PLoS Pathog 2014; 10:e1004120. [PMID: 24945143 PMCID: PMC4055764 DOI: 10.1371/journal.ppat.1004120] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- May M. Paing
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Niraj H. Tolia
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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48
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Malpede BM, Tolia NH. Malaria adhesins: structure and function. Cell Microbiol 2014; 16:621-31. [PMID: 24506585 DOI: 10.1111/cmi.12276] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/13/2014] [Accepted: 01/15/2014] [Indexed: 12/21/2022]
Abstract
The malaria parasite Plasmodium utilizes specialized proteins for adherence to cellular receptors in its mosquito vector and human host. Adherence is critical for parasite development, host cell traversal and invasion, and protection from vector and host immune mechanisms. These vital roles have identified several adhesins as vaccine candidates. A deficiency in current adhesin-based vaccines is induction of antibodies targeting non-conserved, non-functional and decoy epitopes due to the use of full length proteins or binding domains. To alleviate the elicitation of non-inhibitory antibodies, conserved functional regions of proteins must be identified and exploited. Structural biology provides the tools necessary to achieve this goal, and has succeeded in defining biologically functional receptor binding and oligomerization interfaces for a number of promising malaria vaccine candidates. We describe here the current knowledge of Plasmodium adhesin structure and function, and how it has illuminated elements of parasite biology and defined interactions at the host/vector and parasite interface.
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Affiliation(s)
- Brian M Malpede
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Campus Box 8230, 660 S. Euclid Avenue, Saint Louis, MO, 63110, USA
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Higgins MK, Carrington M. Sequence variation and structural conservation allows development of novel function and immune evasion in parasite surface protein families. Protein Sci 2014; 23:354-65. [PMID: 24442723 PMCID: PMC3970887 DOI: 10.1002/pro.2428] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/13/2014] [Accepted: 01/13/2014] [Indexed: 11/27/2022]
Abstract
Trypanosoma and Plasmodium species are unicellular, eukaryotic pathogens that have evolved the capacity to survive and proliferate within a human host, causing sleeping sickness and malaria, respectively. They have very different survival strategies. African trypanosomes divide in blood and extracellular spaces, whereas Plasmodium species invade and proliferate within host cells. Interaction with host macromolecules is central to establishment and maintenance of an infection by both parasites. Proteins that mediate these interactions are under selection pressure to bind host ligands without compromising immune avoidance strategies. In both parasites, the expansion of genes encoding a small number of protein folds has established large protein families. This has permitted both diversification to form novel ligand binding sites and variation in sequence that contributes to avoidance of immune recognition. In this review we consider two such parasite surface protein families, one from each species. In each case, known structures demonstrate how extensive sequence variation around a conserved molecular architecture provides an adaptable protein scaffold that the parasites can mobilise to mediate interactions with their hosts.
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50
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Batchelor JD, Malpede BM, Omattage NS, DeKoster GT, Henzler-Wildman KA, Tolia NH. Red blood cell invasion by Plasmodium vivax: structural basis for DBP engagement of DARC. PLoS Pathog 2014; 10:e1003869. [PMID: 24415938 PMCID: PMC3887093 DOI: 10.1371/journal.ppat.1003869] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 11/22/2013] [Indexed: 01/08/2023] Open
Abstract
Plasmodium parasites use specialized ligands which bind to red blood cell (RBC) receptors during invasion. Defining the mechanism of receptor recognition is essential for the design of interventions against malaria. Here, we present the structural basis for Duffy antigen (DARC) engagement by P. vivax Duffy binding protein (DBP). We used NMR to map the core region of the DARC ectodomain contacted by the receptor binding domain of DBP (DBP-RII) and solved two distinct crystal structures of DBP-RII bound to this core region of DARC. Isothermal titration calorimetry studies show these structures are part of a multi-step binding pathway, and individual point mutations of residues contacting DARC result in a complete loss of RBC binding by DBP-RII. Two DBP-RII molecules sandwich either one or two DARC ectodomains, creating distinct heterotrimeric and heterotetrameric architectures. The DARC N-terminus forms an amphipathic helix upon DBP-RII binding. The studies reveal a receptor binding pocket in DBP and critical contacts in DARC, reveal novel targets for intervention, and suggest that targeting the critical DARC binding sites will lead to potent disruption of RBC engagement as complex assembly is dependent on DARC binding. These results allow for models to examine inter-species infection barriers, Plasmodium immune evasion mechanisms, P. knowlesi receptor-ligand specificity, and mechanisms of naturally acquired P. vivax immunity. The step-wise binding model identifies a possible mechanism by which signaling pathways could be activated during invasion. It is anticipated that the structural basis of DBP host-cell engagement will enable development of rational therapeutics targeting this interaction.
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Affiliation(s)
- Joseph D. Batchelor
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Brian M. Malpede
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Natalie S. Omattage
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Gregory T. DeKoster
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Katherine A. Henzler-Wildman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Niraj H. Tolia
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
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