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Doritchamou J, Nielsen MA, Chêne A, Viebig NK, Lambert LE, Sander AF, Semblat JP, Hundt S, Orr-Gonzalez S, Janitzek CM, Spiegel AJ, Clemmensen SB, Thomas ML, Nason MC, Snow-Smith M, Barnafo EK, Shiloach J, Chen BB, Nadakal S, Highsmith K, Ouahes T, Conteh S, Sharma A, Torano H, Butler B, Reiter K, Rausch KM, Scaria PV, Anderson C, Narum DL, Salanti A, Fried M, Theander TG, Gamain B, Duffy PE. Aotus nancymaae model predicts human immune response to the placental malaria vaccine candidate VAR2CSA. Lab Anim (NY) 2023; 52:315-323. [PMID: 37932470 PMCID: PMC10689237 DOI: 10.1038/s41684-023-01274-2] [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: 09/13/2022] [Accepted: 09/27/2023] [Indexed: 11/08/2023]
Abstract
Placental malaria vaccines (PMVs) are being developed to prevent severe sequelae of placental malaria (PM) in pregnant women and their offspring. The leading candidate vaccine antigen VAR2CSA mediates parasite binding to placental receptor chondroitin sulfate A (CSA). Despite promising results in small animal studies, recent human trials of the first two PMV candidates (PAMVAC and PRIMVAC) generated limited cross-reactivity and cross-inhibitory activity to heterologous parasites. Here we immunized Aotus nancymaae monkeys with three PMV candidates (PAMVAC, PRIMVAC and ID1-ID2a_M1010) adjuvanted with Alhydrogel, and exploited the model to investigate boosting of functional vaccine responses during PM episodes as well as with nanoparticle antigens. PMV candidates induced high levels of antigen-specific IgG with significant cross-reactivity across PMV antigens by enzyme-linked immunosorbent assay. Conversely, PMV antibodies recognized native VAR2CSA and blocked CSA adhesion of only homologous parasites and not of heterologous parasites. PM episodes did not significantly boost VAR2CSA antibody levels or serum functional activity; nanoparticle and monomer antigens alike boosted serum reactivity but not functional activities. Overall, PMV candidates induced functional antibodies with limited heterologous activity in Aotus monkeys, similar to responses reported in humans. The Aotus model appears suitable for preclinical downselection of PMV candidates and assessment of antibody boosting by PM episodes.
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Affiliation(s)
- Justin Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Morten A Nielsen
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Arnaud Chêne
- Université Paris Cité and Université des Antilles, INSERM, BIGR, Paris, France
| | - Nicola K Viebig
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Heidelberg, Germany
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Adam F Sander
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | | | - Sophia Hundt
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Heidelberg, Germany
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Christoph Mikkel Janitzek
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Alicia J Spiegel
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Marvin L Thomas
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, USA
| | - Martha C Nason
- Biostatistics Research Branch, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Maryonne Snow-Smith
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Emma K Barnafo
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joseph Shiloach
- Biotechnology Unit, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Beth B Chen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Steven Nadakal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kendrick Highsmith
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tarik Ouahes
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ankur Sharma
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Holly Torano
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Brandi Butler
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kelly M Rausch
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Puthupparampil V Scaria
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ali Salanti
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thor G Theander
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Benoit Gamain
- Université Paris Cité and Université des Antilles, INSERM, BIGR, Paris, France
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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Yanik S, Venkatesh V, Parker ML, Ramaswamy R, Diouf A, Sarkar D, Miura K, Long CA, Boulanger MJ, Srinivasan P. Structure guided mimicry of an essential P. falciparum receptor-ligand complex enhances cross neutralizing antibodies. Nat Commun 2023; 14:5879. [PMID: 37735574 PMCID: PMC10514071 DOI: 10.1038/s41467-023-41636-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/13/2023] [Indexed: 09/23/2023] Open
Abstract
Invasion of human erythrocytes by Plasmodium falciparum (Pf) merozoites relies on the interaction between two parasite proteins: apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2). While antibodies to AMA1 provide limited protection against Pf in non-human primate malaria models, clinical trials using recombinant AMA1 alone (apoAMA1) yielded no protection due to insufficient functional antibodies. Immunization with AMA1 bound to RON2L, a 49-amino acid peptide from its ligand RON2, has shown superior protection by increasing the proportion of neutralizing antibodies. However, this approach relies on the formation of a complex in solution between the two vaccine components. To advance vaccine development, here we engineered chimeric antigens by replacing the AMA1 DII loop, displaced upon ligand binding, with RON2L. Structural analysis confirmed that the fusion chimera (Fusion-FD12) closely mimics the binary AMA1-RON2L complex. Immunization studies in female rats demonstrated that Fusion-FD12 immune sera, but not purified IgG, neutralized vaccine-type parasites more efficiently compared to apoAMA1, despite lower overall anti-AMA1 titers. Interestingly, Fusion-FD12 immunization enhanced antibodies targeting conserved epitopes on AMA1, leading to increased neutralization of non-vaccine type parasites. Identifying these cross-neutralizing antibody epitopes holds promise for developing an effective, strain-transcending malaria vaccine.
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Affiliation(s)
- Sean Yanik
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - Varsha Venkatesh
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - Michelle L Parker
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
| | - Raghavendran Ramaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Deepti Sarkar
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Martin J Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
| | - Prakash Srinivasan
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA.
- The Johns Hopkins Malaria Research Institute, Baltimore, MD, 21205, USA.
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3
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Patel PN, Dickey TH, Diouf A, Salinas ND, McAleese H, Ouahes T, Long CA, Miura K, Lambert LE, Tolia NH. Structure-based design of a strain transcending AMA1-RON2L malaria vaccine. Nat Commun 2023; 14:5345. [PMID: 37660103 PMCID: PMC10475129 DOI: 10.1038/s41467-023-40878-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/14/2023] [Indexed: 09/04/2023] Open
Abstract
Apical membrane antigen 1 (AMA1) is a key malaria vaccine candidate and target of neutralizing antibodies. AMA1 binds to a loop in rhoptry neck protein 2 (RON2L) to form the moving junction during parasite invasion of host cells, and this complex is conserved among apicomplexan parasites. AMA1-RON2L complex immunization achieves higher growth inhibitory activity than AMA1 alone and protects mice against Plasmodium yoelii challenge. Here, three single-component AMA1-RON2L immunogens were designed that retain the structure of the two-component AMA1-RON2L complex: one structure-based design (SBD1) and two insertion fusions. All immunogens elicited high antibody titers with potent growth inhibitory activity, yet these antibodies did not block RON2L binding to AMA1. The SBD1 immunogen induced significantly more potent strain-transcending neutralizing antibody responses against diverse strains of Plasmodium falciparum than AMA1 or AMA1-RON2L complex vaccination. This indicates that SBD1 directs neutralizing antibody responses to strain-transcending epitopes in AMA1 that are independent of RON2L binding. This work underscores the importance of neutralization mechanisms that are distinct from RON2 blockade. The stable single-component SBD1 immunogen elicits potent strain-transcending protection that may drive the development of next-generation vaccines for improved malaria and apicomplexan parasite control.
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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
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Nichole D Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Holly McAleese
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Lynn E Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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4
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Srinivasan P, Yanik S, Venkatesh V, Parker M, Diouf A, Sarkar D, Miura K, Long C, Boulanger M. Structure guided mimicry of an essential P. falciparum receptor-ligand complex enhances cross neutralizing antibodies. RESEARCH SQUARE 2023:rs.3.rs-2733434. [PMID: 37131813 PMCID: PMC10153359 DOI: 10.21203/rs.3.rs-2733434/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Invasion of human red blood cells (RBCs) by Plasmodium falciparum (Pf) merozoites relies on the interaction between two parasite proteins, apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2) 1,2 . Antibodies to AMA1 confer limited protection against P. falciparum in non-human primate malaria models 3,4 . However, clinical trials with recombinant AMA1 alone (apoAMA1) saw no protection, likely due to inadequate levels of functional antibodies 5-8 . Notably, immunization with AMA1 in its ligand bound conformation using RON2L, a 49 amino acid peptide from RON2, confers superior protection against P. falciparum malaria by enhancing the proportion of neutralizing antibodies 9,10 . A limitation of this approach, however, is that it requires the two vaccine components to form a complex in solution. To facilitate vaccine development, we engineered chimeric antigens by strategically replacing the AMA1 DII loop that is displaced upon ligand binding with RON2L. Structural characterization of the fusion chimera, Fusion-F D12 to 1.55 Å resolution showed that it closely mimics the binary receptor-ligand complex. Immunization studies showed that Fusion-F D12 immune sera neutralized parasites more efficiently than apoAMA1 immune sera despite having an overall lower anti-AMA1 titer, suggesting improvement in antibody quality. Furthermore, immunization with Fusion-F D12 enhanced antibodies targeting conserved epitopes on AMA1 resulting in greater neutralization of non-vaccine type parasites. Identifying epitopes of such cross-neutralizing antibodies will help in the development of an effective, strain-transcending malaria vaccine. Our fusion protein design is a robust vaccine platform that can be enhanced by incorporating polymorphisms in AMA1 to effectively neutralize all P. falciparum parasites.
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Affiliation(s)
| | | | | | | | | | | | | | - Carole Long
- Laboratory of Malaria and Vector Resarch, NIAID/NIH
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5
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Estimation of Plasmodium falciparum transmission using multiepitope chimeric antigen in the postelimination phase in Yunnan, China. Parasitol Int 2022; 89:102597. [DOI: 10.1016/j.parint.2022.102597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/21/2022] [Accepted: 05/03/2022] [Indexed: 11/20/2022]
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Nirmolia T, Ahmed MA, Sathishkumar V, Sarma NP, Bhattacharyya DR, Mohapatra PK, Bansal D, Bharti PK, Sehgal R, Mahanta J, Sultan AA, Narain K, Patgiri SJ. Genetic diversity of Plasmodium falciparum AMA-1 antigen from the Northeast Indian state of Tripura and comparison with global sequences: implications for vaccine development. Malar J 2022; 21:62. [PMID: 35193607 PMCID: PMC8861999 DOI: 10.1186/s12936-022-04081-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/07/2022] [Indexed: 11/18/2022] Open
Abstract
Background Malaria continues to be a major public health problem in the Northeastern part of India despite the implementation of vector control measures and changes in drug policies. To develop successful vaccines against malaria, it is important to assess the diversity of vaccine candidate antigens in field isolates. This study was done to assess the diversity of Plasmodium falciparum AMA-1 vaccine candidate antigen in a malaria-endemic region of Tripura in Northeast India and compare it with previously reported global isolates with a view to assess the feasibility of developing a universal vaccine based on this antigen. Methods Patients with fever and malaria-like illness were screened for malaria and P. falciparum positive cases were recruited for the current study. The diversity of PfAMA-1 vaccine candidate antigen was evaluated by nested PCR and RFLP. A selected number of samples were sequenced using the Sanger technique. Results Among 56 P. falciparum positive isolates, Pfama-1 was successfully amplified in 75% (n = 42) isolates. Allele frequencies of PfAMA-1 antigen were 16.6% (n = 7) for 3D7 allele and 33.3% (n = 14) in both K1 and HB3 alleles. DNA sequencing revealed 13 haplotypes in the Pfama-1 gene including three unique haplotypes not reported earlier. No unique amino-acid substitutions were found. Global analysis with 2761 sequences revealed 435 haplotypes with a very complex network composition and few clusters. Nucleotide diversity for Tripura (0.02582 ± 0.00160) showed concordance with South-East Asian isolates while recombination parameter (Rm = 8) was lower than previous reports from India. Population genetic structure showed moderate differentiation. Conclusions Besides documenting all previously reported allelic forms of the vaccine candidate PfAMA-1 antigen of P. falciparum, new haplotypes not reported earlier, were found in Tripura. Neutrality tests indicate that the Pfama-1 population in Tripura is under balancing selection. This is consistent with global patterns. However, the high haplotype diversity observed in the global Pfama-1 network analysis indicates that designing a universal vaccine based on this antigen may be difficult. This information adds to the existing database of genetic diversity of field isolates of P. falciparum and may be helpful in the development of more effective vaccines against the parasite. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04081-1.
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Affiliation(s)
- Tulika Nirmolia
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Md Atique Ahmed
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Vinayagam Sathishkumar
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Nilanju P Sarma
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India.,SRL Reference Laboratory, Mumbai, 400060, India
| | - Dibya R Bhattacharyya
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Pradyumna K Mohapatra
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Devendra Bansal
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Doha, Qatar.,Ministry of Public Health, Doha, Qatar
| | - Praveen K Bharti
- ICMR - National Institute for Research in Tribal Health, Jabalpur, Madhya Pradesh, 482003, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, Punjab, 160012, India
| | - Jagadish Mahanta
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Ali A Sultan
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Doha, Qatar
| | - Kanwar Narain
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India
| | - Saurav J Patgiri
- ICMR - Regional Medical Research Centre, North East Region, Dibrugarh, Assam, 786001, India.
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Rittipornlertrak A, Nambooppha B, Muenthaisong A, Punyapornwithaya V, Tiwananthagorn S, Chung YT, Tuvshintulga B, Sivakumar T, Yokoyama N, Sthitmatee N. Structural and immunological characterization of an epitope within the PAN motif of ectodomain I in Babesia bovis apical membrane antigen 1 for vaccine development. PeerJ 2021; 9:e11765. [PMID: 34316404 PMCID: PMC8288113 DOI: 10.7717/peerj.11765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/22/2021] [Indexed: 11/25/2022] Open
Abstract
Background Bovine babesiosis caused by Babesia bovis (B. bovis) has had a significant effect on the mobility and mortality rates of the cattle industry worldwide. Live-attenuated vaccines are currently being used in many endemic countries, but their wide use has been limited for a number of reasons. Although recombinant vaccines have been proposed as an alternative to live vaccines, such vaccines are not commercially available to date. Apical membrane antigen-1 (AMA-1) is one of the leading candidates in the development of a vaccine against diseases caused by apicomplexan parasite species. In Plasmodium falciparum (P. falciparum) AMA-1 (PfAMA-1), several antibodies against epitopes in the plasminogen, apple, and nematode (PAN) motif of PfAMA-1 domain I significantly inhibited parasite growth. Therefore, the purpose of this study was to predict an epitope from the PAN motif of domain I in the B. bovis AMA-1 (BbAMA-1) using a combination of linear and conformational B-cell epitope prediction software. The selected epitope was then bioinformatically analyzed, synthesized as a peptide (sBbAMA-1), and then used to immunize a rabbit. Subsequently, in vitro growth- and the invasion-inhibitory effects of the rabbit antiserum were immunologically characterized. Results Our results demonstrated that the predicted BbAMA-1 epitope was located on the surface-exposed α-helix of the PAN motif in domain I at the apex area between residues 181 and 230 with six polymorphic sites. Subsequently, sBbAMA-1 elicited antibodies capable of recognizing the native BbAMA-1 in immunoassays. Furthermore, anti-serum against sBbAMA-1 was immunologically evaluated for its growth- and invasion-inhibitory effects on B. bovis merozoites in vitro. Our results demonstrated that the rabbit anti-sBbAMA-1 serum at a dilution of 1:5 significantly inhibited (p < 0.05) the growth of B. bovis merozoites by approximately 50–70% on days 3 and 4 of cultivation, along with the invasion of merozoites by approximately 60% within 4 h of incubation when compared to the control groups. Conclusion Our results indicate that the epitope predicted from the PAN motif of BbAMA-1 domain I is neutralization-sensitive and may serve as a target antigen for vaccine development against bovine babesiosis caused by B. bovis.
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Affiliation(s)
| | - Boondarika Nambooppha
- Graduate School of Veterinary Sciences, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Anucha Muenthaisong
- Graduate School of Veterinary Sciences, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Veerasak Punyapornwithaya
- Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Saruda Tiwananthagorn
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Yang-Tsung Chung
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - Bumduuren Tuvshintulga
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Nattawooti Sthitmatee
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
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8
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Dwomoh D, Adu B, Dodoo D, Theisen M, Iddi S, Gerds TA. Evaluating the predictive performance of malaria antibodies and FCGR3B gene polymorphisms on Plasmodium falciparum infection outcome: a prospective cohort study. Malar J 2020; 19:307. [PMID: 32854708 PMCID: PMC7450914 DOI: 10.1186/s12936-020-03381-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 08/19/2020] [Indexed: 12/03/2022] Open
Abstract
Background Malaria antigen-specific antibodies and polymorphisms in host receptors involved in antibody functionality have been associated with different outcomes of Plasmodium falciparum infections. Thus, to identify key prospective malaria antigens for vaccine development, there is the need to evaluate the associations between malaria antibodies and antibody dependent host factors with more rigorous statistical methods. In this study, different statistical models were used to evaluate the predictive performance of malaria-specific antibodies and host gene polymorphisms on P. falciparum infection in a longitudinal cohort study involving Ghanaian children. Methods Models with different functional forms were built using known predictors (age, sickle cell status, blood group status, parasite density, and mosquito bed net use) and malaria antigen-specific immunoglobulin (Ig) G and IgG subclasses and FCGR3B polymorphisms shown to mediate antibody-dependent cellular functions. Malaria antigens studied were Merozoite surface proteins (MSP-1 and MSP-3), Glutamate Rich Protein (GLURP)-R0, R2, and the Apical Membrane Antigen (AMA-1). The models were evaluated through visualization and assessment of differences between the Area Under the Receiver Operating Characteristic Curve and Brier Score estimated by suitable internal cross-validation designs. Results This study found that the FCGR3B-c.233C>A genotype and IgG against AMA1 were relatively better compared to the other antibodies and FCGR3B genotypes studied in classifying or predicting malaria risk among children. Conclusions The data supports the P. falciparum, AMA1 as an important malaria vaccine antigen, while FCGR3B-c.233C>A under the additive and dominant models of inheritance could be an important modifier of the effect of malaria protective antibodies.
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Affiliation(s)
- Duah Dwomoh
- Department of Biostatistics, School of Public Health, University of Ghana, Accra, Ghana.
| | - Bright Adu
- Department of Immunology, Noguchi Memorial Institute of Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Daniel Dodoo
- Department of Immunology, Noguchi Memorial Institute of Medical Research, College of Health Sciences, 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.,Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Samuel Iddi
- Department of Statistics and Actuarial Sciences, University of Ghana, Accra, Ghana
| | - Thomas A Gerds
- Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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9
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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: 15] [Impact Index Per Article: 3.0] [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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10
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Drew DR, Sanders PR, Weiss G, Gilson PR, Crabb BS, Beeson JG. Functional Conservation of the AMA1 Host-Cell Invasion Ligand Between P. falciparum and P. vivax: A Novel Platform to Accelerate Vaccine and Drug Development. J Infect Dis 2019; 217:498-507. [PMID: 29165651 DOI: 10.1093/infdis/jix583] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/17/2017] [Indexed: 01/20/2023] Open
Abstract
Plasmodium vivax and P. falciparum malaria species have diverged significantly in receptor-ligand interactions and host-cell invasion. One protein common to both is the merozoite invasion ligand AMA1. While the general structure of AMA1 is similar between species, their sequences are divergent. Surprisingly, it was possible to genetically replace PfAMA1 with PvAMA1 in P. falciparum parasites. PvAMA1 complemented PfAMA1 function and supported invasion of erythrocytes by P. falciparum. Genetically modified P. falciparum expressing PvAMA1 evaded the invasion inhibitory effects of antibodies to PfAMA1, demonstrating species specificity of functional antibodies. We generated antibodies to recombinant PvAMA1 that effectively inhibited invasion, confirming the function of PvAMA1 in genetically modified parasites. Results indicate significant molecular flexibility in AMA1 enabling conserved function despite substantial sequence divergence across species. This provides powerful new tools to quantify the inhibitory activities of antibodies or drugs targeting PvAMA1, opening new opportunities for vaccine and therapeutic development against P. vivax.
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Affiliation(s)
| | | | | | | | - Brendan S Crabb
- Burnet Institute, Melbourne, Australia.,Department of Medicine, University of Melbourne, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne, Victoria, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Australia.,Department of Medicine, University of Melbourne, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne, Victoria, Australia.,Central Clinical School and Department of Microbiology, Monash University, Victoria, Australia
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11
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Bittencourt NC, Leite JA, Silva ABIE, Pimenta TS, Silva-Filho JL, Cassiano GC, Lopes SCP, Dos-Santos JCK, Bourgard C, Nakaya HI, da Silva Ventura AMR, Lacerda MVG, Ferreira MU, Machado RLD, Albrecht L, Costa FTM. Genetic sequence characterization and naturally acquired immune response to Plasmodium vivax Rhoptry Neck Protein 2 (PvRON2). Malar J 2018; 17:401. [PMID: 30382855 PMCID: PMC6208078 DOI: 10.1186/s12936-018-2543-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 10/22/2018] [Indexed: 12/28/2022] Open
Abstract
Background The genetic diversity of malaria antigens often results in allele variant-specific immunity, imposing a great challenge to vaccine development. Rhoptry Neck Protein 2 (PvRON2) is a blood-stage antigen that plays a key role during the erythrocyte invasion of Plasmodium vivax. This study investigates the genetic diversity of PvRON2 and the naturally acquired immune response to P. vivax isolates. Results Here, the genetic diversity of PvRON21828–2080 and the naturally acquired humoral immune response against PvRON21828–2080 in infected and non-infected individuals from a vivax malaria endemic area in Brazil was reported. The diversity analysis of PvRON21828–2080 revealed that the protein is conserved in isolates in Brazil and worldwide. A total of 18 (19%) patients had IgG antibodies to PvRON21828–2080. Additionally, the analysis of the antibody response in individuals who were not acutely infected with malaria, but had been infected with malaria in the past indicated that 32 patients (33%) exhibited an IgG immune response against PvRON2. Conclusions PvRON2 was conserved among the studied isolates. The presence of naturally acquired antibodies to this protein in the absence of the disease suggests that PvRON2 induces a long-term antibody response. These results indicate that PvRON2 is a potential malaria vaccine candidate. Electronic supplementary material The online version of this article (10.1186/s12936-018-2543-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Najara C Bittencourt
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | - Juliana A Leite
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | | | - Tamirys S Pimenta
- Laboratório de Ensaios Clínicos e Imunogenética em Malária, Instituto Evandro Chagas/SVS/MS, Ananindeua, PA, Brazil
| | - João Luiz Silva-Filho
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | - Gustavo C Cassiano
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | - Stefanie C P Lopes
- Instituto Leônidas & Maria Deane, Fundação Oswaldo Cruz - FIOCRUZ, Manaus, AM, Brazil.,Fundação de Medicina Tropical-Dr. Heitor Vieira Dourado, Manaus, AM, Brazil
| | - Joao C K Dos-Santos
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | - Catarina Bourgard
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil
| | - Helder I Nakaya
- School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Marcus V G Lacerda
- Instituto Leônidas & Maria Deane, Fundação Oswaldo Cruz - FIOCRUZ, Manaus, AM, Brazil.,Fundação de Medicina Tropical-Dr. Heitor Vieira Dourado, Manaus, AM, Brazil
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo-USP, São Paulo, Brazil
| | - Ricardo L D Machado
- Laboratório de Ensaios Clínicos e Imunogenética em Malária, Instituto Evandro Chagas/SVS/MS, Ananindeua, PA, Brazil
| | - Letusa Albrecht
- Instituto Carlos Chagas, Fundação Oswaldo Cruz - FIOCRUZ, Curitiba, PR, Brazil.
| | - Fabio T M Costa
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas-UNICAMP, Campinas, SP, Brazil.
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12
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Abstract
Evidence accumulated through the years clearly indicates that antiparasite immune responses can efficiently control malaria parasite infection at all development stages, and under certain circumstances they can prevent parasite infection. Translating these findings into vaccines or immunotherapeutic interventions has been difficult in part because of the extraordinary biological complexity of this parasite, which has several developmental stages expressing unique sets of stage-specific genes and multiple antigens, most of which are antigenically diverse. Nevertheless, in the last 30 years major advances have resulted in characterization of a number of vaccine candidates, exploration of the repertoire of host immune responses to the various parasite stages, and also identification of significant hurdles that need to be overcome. Most important, these advances strengthened the concept that the induction of host immune responses that target all developmental stages of Plasmodium can efficiently control or abrogate Plasmodium infections and strongly support the notion that an effective vaccine can be developed. This vaccine would be a critical component for programs aimed at controlling or eradicating malaria.
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Affiliation(s)
- Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institute of Health, Rockville, Maryland 20852
| | - Fidel Zavala
- Departmentof Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
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13
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Onkoba N, Mumo RM, Ochanda H, Omwandho C, Ozwara HS, Egwang TG. Safety, immunogenicity, and cross-species protection of a plasmid DNA encoding Plasmodium falciparum SERA5 polypeptide, microbial epitopes and chemokine genes in mice and olive baboons. J Biomed Res 2017; 31:321-332. [PMID: 28808204 PMCID: PMC5548993 DOI: 10.7555/jbr.31.20160025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 12/29/2016] [Indexed: 11/03/2022] Open
Abstract
Incorporation of biomolecular epitopes to malarial antigens should be explored in the development of strain-transcending malarial vaccines. The present study sought to determine safety, immunogenicity and cross-species efficacy ofPlasmodium falciparum serine repeat antigen 5 polypeptide co-expressed with epitopes of Bacille-Calmette Guerin (BCG), tetanus toxoid (TT) and a chemokine gene. Olive baboons and BALB/c mice were randomly assigned into vaccine and control groups. The vaccine group animals were primed and boosted twice with pIRES plasmids encoding the SERA5+ BCG+ TT alone, or with either CCL5 or CCL20 and the control group with pIRES plasmid vector backbone. Mice and baboons were challenged withP. berghei ANKA and P. knowlesi H strain parasites, respectively. Safety was determined by observing for injection sites reactogenicities, hematology and clinical chemistry. Parasitaemia and survivorship profiles were used to determine cross-species efficacy, and T cell phenotypes, Th1-, Th2-type, T-regulatory immune responses and antibody responses were assessed to determine vaccine immunogenicity. The pSeBCGTT plasmid DNA vaccines were safe and induced Th1-, Th2-type, and T-regulatory responses vaccinated animals showed enhanced CD4+ (P<0.01), CD 8+ T cells (P<0.001) activation and IgG anti-SE36 antibodies responses (P<0.001) at week 4 and 8 post vaccination compared to the control group. Vaccinated mice had a 31.45-68.69% cumulative parasite load reduction and 60% suppression in baboons (P<0.05) and enhanced survivorship (P<0.001) with no clinical signs of malaria compared to the control group. The results showed that the vaccines were safe, immunogenic and conferred partial cross-species protection.
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Affiliation(s)
- Nyamongo Onkoba
- . Department of Tropical & Infectious Diseases, Institute of Primate Research, Nairobi P. O. Box 24481-00502, Kenya
- . School of Biological Sciences, University of Nairobi, Nairobi P. O. Box 30197-00100, Kenya
| | - Ruth M. Mumo
- . Department of Tropical & Infectious Diseases, Institute of Primate Research, Nairobi P. O. Box 24481-00502, Kenya
- . Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi P. O. Box 30197-00100, Kenya
| | - Horace Ochanda
- . School of Biological Sciences, University of Nairobi, Nairobi P. O. Box 30197-00100, Kenya
| | - Charles Omwandho
- . Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi P. O. Box 30197-00100, Kenya
- . Kirinyaga University College, Kerugoya P. O. Box 143-10300, Kenya
| | - Hastings S. Ozwara
- . Department of Tropical & Infectious Diseases, Institute of Primate Research, Nairobi P. O. Box 24481-00502, Kenya
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14
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Srinivasan P, Baldeviano GC, Miura K, Diouf A, Ventocilla JA, Leiva KP, Lugo-Roman L, Lucas C, Orr-Gonzalez S, Zhu D, Villasante E, Soisson L, Narum DL, Pierce SK, Long CA, Diggs C, Duffy PE, Lescano AG, Miller LH. A malaria vaccine protects Aotus monkeys against virulent Plasmodium falciparum infection. NPJ Vaccines 2017; 2. [PMID: 28804644 PMCID: PMC5551459 DOI: 10.1038/s41541-017-0015-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Plasmodium falciparum protein, apical membrane antigen 1 forms a complex with another parasite protein, rhoptry neck protein 2, to initiate junction formation with the erythrocyte and is essential for merozoite invasion during the blood stage of infection. Consequently, apical membrane antigen 1 has been a target of vaccine development but vaccination with apical membrane antigen 1 alone in controlled human malaria infections failed to protect and showed limited efficacy in field trials. Here we show that vaccination with AMA1–RON2L complex in Freund’s adjuvant protects Aotus monkeys against a virulent Plasmodium falciparum infection. Vaccination with AMA1 alone gave only partial protection, delaying infection in one of eight animals. However, the AMA1–RON2L complex vaccine completely protected four of eight monkeys and substantially delayed infection (>25 days) in three of the other four animals. Interestingly, antibodies from monkeys vaccinated with the AMA1–RON2L complex had significantly higher neutralizing activity than antibodies from monkeys vaccinated with AMA1 alone. Importantly, we show that antibodies from animals vaccinated with the complex have significantly higher neutralization activity against non-vaccine type parasites. We suggest that vaccination with the AMA1–RON2L complex induces functional antibodies that better recognize AMA1 as it appears complexed with RON2 during merozoite invasion. These data justify progression of this next generation AMA1 vaccine towards human trials. A vaccine targeting a protein complex that allows malaria-causing parasite to enter red blood cells has been produced. Malaria caused by the parasite Plasmodium falciparum is an oft-deadly infectious disease without an effective vaccine. A team of researchers at the National Institutes of Health led by Prakash Srinivasan, currently at the Johns Hopkins Malaria Research Institute, United States, demonstrated the efficacy of a vaccine candidate that works by priming a host’s immune system to a parasitic protein complex required to form a junction with red blood cells, allowing entry and proliferation of the pathogen. The group’s vaccine conferred more effective protection in monkeys than prior candidates that targeted only one component of the parasitic protein complex. This research warrants a closer look into how this candidate, and others targeting the protein complex, can be used to prevent malaria in humans.
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Affiliation(s)
- Prakash Srinivasan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Karina P Leiva
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Luis Lugo-Roman
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Carmen Lucas
- US Naval Medical Research Unit No. 6 (NAMRU-6), Callao, Peru
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Daming Zhu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Eileen Villasante
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD, USA
| | - Lorraine Soisson
- Malaria Vaccine Development Program, U.S. Agency for International Development, Washington, DC, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Carter Diggs
- Malaria Vaccine Development Program, U.S. Agency for International Development, Washington, DC, USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
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15
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A Plasmodium vivax Plasmid DNA- and Adenovirus-Vectored Malaria Vaccine Encoding Blood-Stage Antigens AMA1 and MSP1 42 in a Prime/Boost Heterologous Immunization Regimen Partially Protects Aotus Monkeys against Blood-Stage Challenge. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00539-16. [PMID: 28179404 DOI: 10.1128/cvi.00539-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/06/2017] [Indexed: 01/30/2023]
Abstract
Malaria is caused by parasites of the genus Plasmodium, which are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of Plasmodium falciparum, it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside Africa, stressing the importance of developing a vaccine against P. vivax malaria. In this study, we assessed the immunogenicity and protective efficacy of two P. vivax antigens, apical membrane antigen 1 (AMA1) and the 42-kDa C-terminal fragment of merozoite surface protein 1 (MSP142) in a plasmid recombinant DNA prime/adenoviral (Ad) vector boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with plasmid DNA alone, Ad alone, prime/boost regimens with each antigen, prime/boost regimens with both antigens, and empty vector controls and then subjected to blood-stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, on the basis of their ability to induce the longest prepatent period and the longest time to the peak level of parasitemia, the lowest peak and mean levels of parasitemia, the smallest area under the parasitemia curve, and the highest self-cure rate. Overall, prechallenge MSP142 antibody titers strongly correlated with a decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, the P. vivax plasmid DNA/Ad serotype 5 vaccine encoding blood-stage parasite antigens AMA1 and MSP142 in a heterologous prime/boost immunization regimen provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and this regimen for further development.
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16
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Zhu X, Zhao P, Wang S, Liu F, Liu J, Wang J, Yang Z, Yan G, Fan Q, Cao Y, Cui L. Analysis of Pvama1 genes from China-Myanmar border reveals little regional genetic differentiation of Plasmodium vivax populations. Parasit Vectors 2016; 9:614. [PMID: 27899135 PMCID: PMC5129220 DOI: 10.1186/s13071-016-1899-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/21/2016] [Indexed: 12/22/2022] Open
Abstract
Background With the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations. Here we evaluated the genetic diversity of Plasmodium vivax apical membrane antigen 1 (Pvama1) gene in a parasite population from the China-Myanmar border and compared it with global P. vivax populations. Methods We performed evolutionary analysis to examine the genetic diversity, natural selection, and population differentiation of 73 Pvama1 sequences acquired from the China-Myanmar border as well as 615 publically available Pvama1 sequences from seven global P. vivax populations. Results A total of 308 Pvama1 haplotypes were identified among the global P. vivax isolates. The overall nucleotide diversity of Pvama1 gene among the 73 China-Myanmar border parasite isolates was 0.008 with 41 haplotypes being identified (Hd = 0.958). Domain I (DI) harbored the majority (26/33) of the polymorphic sites. The McDonald Kreitman test showed a significant positive selection across the ectodomain and the DI of Pvama1. The fixation index (FST) estimation between the China-Myanmar border, Thailand (0.01) and Myanmar (0.10) showed only slight geographical genetic differentiation. Notably, the Sal-I haplotype was not detected in any of the analyzed global isolates, whereas the Belem strain was restricted to the Thai population. The detected mutations are mapped outside the overlapped region of the predicted B-cell epitopes and intrinsically unstructured/disordered regions. Conclusions This study revealed high levels of genetic diversity of Pvama1 in the P. vivax parasite population from the China-Myanmar border with DI displaying stronger diversifying selection than other domains. There were low levels of population subdivision among parasite populations from the Greater Mekong Subregion. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1899-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Pan Zhao
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Si Wang
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Jun Liu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Jian Wang
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA, USA
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China.
| | - Liwang Cui
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China. .,Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA.
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17
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Imboumy-Limoukou RK, Oyegue-Liabagui SL, Ndidi S, Pegha-Moukandja I, Kouna CL, Galaway F, Florent I, Lekana-Douki JB. Comparative Antibody Responses Against three Antimalarial Vaccine Candidate Antigens from Urban and Rural Exposed Individuals in Gabon. Eur J Microbiol Immunol (Bp) 2016; 6:287-297. [PMID: 27980857 PMCID: PMC5146647 DOI: 10.1556/1886.2016.00027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 08/15/2016] [Indexed: 12/12/2022] Open
Abstract
The analysis of immune responses in diverse malaria endemic regions provides more information to understand the host's immune response to Plasmodium falciparum. Several plasmodial antigens have been reported as targets of human immunity. PfAMA1 is one of most studied vaccine candidates; PfRH5 and Pf113 are new promising vaccine candidates. The aim of this study was to evaluate humoral response against these three antigens among children of Lastourville (rural area) and Franceville (urban area). Malaria was diagnosed using rapid diagnosis tests. Plasma samples were tested against these antigens by enzyme-linked immunosorbent assay (ELISA). We found that malaria prevalence was five times higher in the rural area than in the urban area (p < 0.0001). The anti-PfAMA1 and PfRh5 response levels were significantly higher in Lastourville than in Franceville (p < 0.0001; p = 0.005). The anti-AMA1 response was higher than the anti-Pf113 response, which in turn was higher than the anti-PfRh5 response in both sites. Anti-PfAMA1 levels were significantly higher in infected children than those in uninfected children (p = 0.001) in Franceville. Anti-Pf113 and anti-PfRh5 antibody levels were lowest in children presenting severe malarial anemia. These three antigens are targets of immunity in Gabon. Further studies on the role of Pf113 in antimalarial protection against severe anemia are needed.
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Affiliation(s)
- Roméo-Karl Imboumy-Limoukou
- Unité de Parasitologie Médicale (UPARAM), Centre International de Recherches Médicales de Franceville (CIRMF), BP 769 Franceville, Gabon; Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d'Histoire Naturelle, CNRS, CP52, 57 rue Cuvier 75005 Paris, France; Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876 Franceville, Gabon
| | - Sandrine Lydie Oyegue-Liabagui
- Laboratoire de Recherches en Immunologie, Parasitologie et Microbiologie, Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC) , BP 876 Franceville, Gabon
| | - Stella Ndidi
- Unité de Parasitologie Médicale (UPARAM), Centre International de Recherches Médicales de Franceville (CIRMF) , BP 769 Franceville, Gabon
| | - Irène Pegha-Moukandja
- Unité de Parasitologie Médicale (UPARAM), Centre International de Recherches Médicales de Franceville (CIRMF), BP 769 Franceville, Gabon; Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876 Franceville, Gabon
| | - Charlene Lady Kouna
- Unité de Parasitologie Médicale (UPARAM), Centre International de Recherches Médicales de Franceville (CIRMF) , BP 769 Franceville, Gabon
| | | | - Isabelle Florent
- Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d'Histoire Naturelle, CNRS, CP52 , 57 rue Cuvier 75005 Paris, France
| | - Jean Bernard Lekana-Douki
- Unité de Parasitologie Médicale (UPARAM), Centre International de Recherches Médicales de Franceville (CIRMF), BP 769 Franceville, Gabon; Département de Parasitologie-Mycologie, Université des Sciences de la Santé, BP 4008 Libreville, Gabon
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18
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Yao MX, Sun XD, Gao YH, Cheng ZB, Deng WW, Zhang JJ, Wang H. Multi-epitope chimeric antigen used as a serological marker to estimate Plasmodium falciparum transmission intensity in the border area of China-Myanmar. Infect Dis Poverty 2016; 5:98. [PMID: 27604628 PMCID: PMC5015264 DOI: 10.1186/s40249-016-0194-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/02/2016] [Indexed: 11/28/2022] Open
Abstract
Background Following the decline of malaria transmission in many countries and regions, serological parameters have become particularly useful for estimating malaria transmission in low-intensity areas. This study evaluated a novel serological marker, Malaria Random Constructed Antigen-1 (M.RCAg-1), which contains 11 epitopes from eight Plasmodium falciparum antigens, as a tool for assessing malaria transmission intensity along the border area of China-Myanmar. Method Serum from Plasmodium falciparum and P. vivax patients was used to detect the properties of M.RCAg-1 and antibody responses. Cross-sectional surveys were conducted at the China-Myanmar border and in Hainan province in 2012 and 2013 using cluster sampling. Filter blood spot papers were collected from all participants. Antibodies against M.RCAg-1 were detected using indirect ELISA. The Mann–Whitney test and Spearman’s rank correlation test were performed to analyze antibody data. P. falciparum malaria transmission intensity was estimated using a catalytic conversion model based on the maximum likelihood of generating a community seroconversion rate (SCR). Results M.RCAg-1 was well-recognized by the naturally acquired anti-malaria antibodies in P. falciparum patients and had very limited cross-reactivity with P. vivax infection. The total amount of IgG antibodies was decreased with the decrease in parasitemia after taking medication and lasted several weeks. In a population survey, the antibody levels were higher in residents living close to the China-Myanmar border than those living in non-epidemic areas (P < 0.0001), but no significant difference was observed between residents from Hainan and non-epidemic areas. The calculated SCR was 0.0128 for Jieyangka, 0.004 for Susuzhai, 0.0047 for Qiushan, and 0.043 for Kayahe. The estimated exposure rate obtained from the anti-M.RCAg-1 antibody level correlated with traditional measures of transmission intensity derived from altitude. Conclusion Our study demonstrates that M.RCAg-1 is potentially useful as a serological indicator of exposure to P. falciparum malaria, especially for malaria surveillance in low transmission areas. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0194-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mei-Xue Yao
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Xiao-Dong Sun
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Yu-Hui Gao
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Zhi-Bin Cheng
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Wei-Wei Deng
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Jia-Jia Zhang
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Heng Wang
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
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Thera MA, Coulibaly D, Kone AK, Guindo AB, Traore K, Sall AH, Diarra I, Daou M, Traore IM, Tolo Y, Sissoko M, Niangaly A, Arama C, Baby M, Kouriba B, Sissoko MS, Sagara I, Toure OB, Dolo A, Diallo DA, Remarque E, Chilengi R, Noor R, Sesay S, Thomas A, Kocken CH, Faber BW, Imoukhuede EB, Leroy O, Doumbo OK. Phase 1 randomized controlled trial to evaluate the safety and immunogenicity of recombinant Pichia pastoris-expressed Plasmodium falciparum apical membrane antigen 1 (PfAMA1-FVO [25-545]) in healthy Malian adults in Bandiagara. Malar J 2016; 15:442. [PMID: 27577237 PMCID: PMC5006270 DOI: 10.1186/s12936-016-1466-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 07/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The safety and immunogenicity of PfAMA1, adjuvanted with Alhydrogel(®) was assessed in malaria-experienced Malian adults. The malaria vaccine, PfAMA1-FVO [25-545] is a recombinant protein Pichia pastoris-expressed AMA-1 from Plasmodium falciparum FVO clone adsorbed to Alhydrogel(®), the control vaccine was tetanus toxoid produced from formaldehyde detoxified and purified tetanus toxin. METHODS A double blind randomized controlled phase 1 study enrolled and followed 40 healthy adults aged 18-55 years in Bandiagara, Mali, West Africa, a rural setting with intense seasonal transmission of P. falciparum malaria. Volunteers were randomized to receive either 50 µg of malaria vaccine or the control vaccine. Three doses of vaccine were given on Days 0, 28 and 56, and participants were followed for 1 year. Solicited symptoms were assessed for seven days and unsolicited symptoms for 28 days after each vaccination. Serious adverse events were assessed throughout the study. The titres of anti-AMA-1 antibodies were measured by ELISA and P. falciparum growth inhibition assays were performed. RESULTS Commonest local solicited adverse events were the injection site pain and swelling more frequent in the PfAMA1 group. No vaccine related serious adverse events were reported. A significant 3.5-fold increase of anti-AMA-1 IgG antibodies was observed in malaria vaccine recipients four weeks after the third immunization compared to the control group. CONCLUSION The PfAMA1 showed a good safety profile. Most adverse events reported were of mild to moderate intensity. In addition, the vaccine induced a significant though short-lived increase in the anti-AMA1 IgG titres. Registered on www.clinicaltrials.gov with the number NCT00431808.
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Affiliation(s)
- Mahamadou A Thera
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali.
| | - Drissa Coulibaly
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K Kone
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Ando B Guindo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Karim Traore
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdourhamane H Sall
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Issa Diarra
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Modibo Daou
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Idrissa M Traore
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Youssouf Tolo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mady Sissoko
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Charles Arama
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mounirou Baby
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Bourema Kouriba
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mahamadou S Sissoko
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Ousmane B Toure
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amagana Dolo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Dapa A Diallo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Edmond Remarque
- Biomedical Primate Research Center (BPRC), P.O. Box 3306, 2280 GH, Rijswijk, The Netherlands
| | - Roma Chilengi
- Center for Infectious Diseases Research in Zambia (CIDRZ), P.O. Box 34681, Lusaka, 10101, Zambia
| | - Ramadhani Noor
- African Malaria Network Trust (AMANET), P.O. Box 33207, Dar Es Salaam, Tanzania
| | - Sanie Sesay
- Medical Research Council, P.O. Box 273, Banjul, The Gambia
| | - Alan Thomas
- Biomedical Primate Research Center (BPRC), P.O. Box 3306, 2280 GH, Rijswijk, The Netherlands
| | - Clemens H Kocken
- Biomedical Primate Research Center (BPRC), P.O. Box 3306, 2280 GH, Rijswijk, The Netherlands
| | - Bart W Faber
- Biomedical Primate Research Center (BPRC), P.O. Box 3306, 2280 GH, Rijswijk, The Netherlands
| | | | - Odile Leroy
- European Vaccine Initiative, European Vaccine Initiative, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Ogobara K Doumbo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technologies, Bamako, Mali
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Persistence and immunogenicity of chemically attenuated blood stage Plasmodium falciparum in Aotus monkeys. Int J Parasitol 2016; 46:581-91. [PMID: 27238088 DOI: 10.1016/j.ijpara.2016.05.002] [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: 12/11/2015] [Revised: 04/05/2016] [Accepted: 05/03/2016] [Indexed: 12/24/2022]
Abstract
Malaria is a disease caused by a protozoan of the Plasmodium genus and results in 0.5-0.7million deaths per year. Increasing drug resistance of the parasite and insecticide resistance of mosquitoes necessitate alternative control measures. Numerous vaccine candidates have been identified but none have been able to induce robust, long-lived protection when evaluated in malaria endemic regions. Rodent studies have demonstrated that chemically attenuated blood stage parasites can persist at sub-patent levels and induce homologous and heterologous protection against malaria. Parasite-specific cellular responses were detected, with protection dependent on CD4+ T cells. To investigate this vaccine approach for Plasmodium falciparum, we characterised the persistence and immunogenicity of chemically attenuated P. falciparum FVO strain parasites (CAPs) in non-splenectomised Aotus nancymaae monkeys following administration of a single dose. Control monkeys received either normal red blood cells or wild-type parasites followed by drug treatment. Chemical attenuation was performed using tafuramycin A, which irreversibly binds to DNA. CAPs were detected in the peripheral blood for up to 2days following inoculation as determined by thick blood smears, and for up to 8days as determined by quantitative PCR. Parasite-specific IgG was not detected in monkeys that received CAPs; however, in vitro parasite-specific T cell proliferation was observed. Following challenge, the CAP monkeys developed an infection; however, one CAP monkey and the infection and drug-cure monkeys showed partial or complete resistance. These experiments lay the groundwork for further assessment of CAPs as a potential vaccine against malaria.
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21
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Graves SF, Kouriba B, Diarra I, Daou M, Niangaly A, Coulibaly D, Keita Y, Laurens MB, Berry AA, Vekemans J, Ripley Ballou W, Lanar DE, Dutta S, Gray Heppner D, Soisson L, Diggs CL, Thera MA, Doumbo OK, Plowe CV, Sztein MB, Lyke KE. Strain-specific Plasmodium falciparum multifunctional CD4+ T cell cytokine expression in Malian children immunized with the FMP2.1/AS02A vaccine candidate. Vaccine 2016; 34:2546-55. [DOI: 10.1016/j.vaccine.2016.04.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 03/24/2016] [Accepted: 04/07/2016] [Indexed: 12/17/2022]
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22
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Burns JM, Miura K, Sullivan J, Long CA, Barnwell JW. Immunogenicity of a chimeric Plasmodium falciparum merozoite surface protein vaccine in Aotus monkeys. Malar J 2016; 15:159. [PMID: 26975721 PMCID: PMC4791798 DOI: 10.1186/s12936-016-1226-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/10/2016] [Indexed: 11/23/2022] Open
Abstract
Background The production of properly folded, recombinant sub-unit Plasmodium falciparum malaria vaccine candidates in sufficient quantities is often a challenge. Success in vaccine immunogenicity studies in small animal models does not always predict immunogenicity in non-human primates and/or human subjects. The aim of this study was to assess the immunogenicity of a chimeric blood-stage malaria vaccine in Aotus monkeys. This vaccine candidate includes the neutralizing B cell epitopes of P. falciparum merozoite surface protein 1 (rPfMSP119) genetically linked to a highly immunogenic, well-conserved P. falciparum merozoite surface protein 8 (rPfMSP8 (ΔAsn/Asp)) partner. Methods Aotus nancymaae monkeys were immunized with purified rPfMSP1/8 or rPfMSP8 (ΔAsn/Asp) formulated with Montanide ISA 720 as adjuvant, or with adjuvant alone. Antibody responses to MSP119 and MSP8 domains were measured by ELISA following primary, secondary and tertiary immunizations. The functionality of vaccine-induced antibodies was assessed in a standard P. falciparum blood-stage in vitro growth inhibition assay. Non-parametric tests with corrections for multiple comparisons when appropriate were used to determine the significance of differences in antigen-specific IgG titres and in parasite growth inhibition. Results The chimeric rPfMSP1/8 vaccine was shown to be well tolerated and highly immunogenic with boost-able antibody responses elicited to both PfMSP8 and PfMSP119 domains. Elicited antibodies were highly cross-reactive between FVO and 3D7 alleles of PfMSP119 and potently inhibited the in vitro growth of P. falciparum blood-stage parasites. Conclusions Similar to previous results with inbred and outbred mice and with rabbits, the PfMSP1/8 vaccine was shown to be highly effective in eliciting P. falciparum growth inhibitory antibodies upon immunization of non-human primates. The data support the further assessment of PfMSP1/8 as a component of a multivalent vaccine for use in human subjects. As important, the data indicate that rPfMSP8 (ΔAsn/Asp) can be used as a malaria specific carrier protein to: (1) drive production of antibody responses to neutralizing B cell epitopes of heterologous vaccine candidates and (2) facilitate production of properly folded, recombinant P. falciparum subunit vaccines in high yield.
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Affiliation(s)
- James M Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA.
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - JoAnn Sullivan
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Carole A Long
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA.,Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - John W Barnwell
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
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Abstract
There have been significant decreases in malaria mortality and morbidity in the last 10-15 years, and the most advanced pre-erythrocytic malaria vaccine, RTS,S, received a positive opinion from European regulators in July 2015. However, no blood-stage vaccine has reached a phase III trial. The first part of this review summarizes the pros and cons of various assays and models that have been and will be used to predict the efficacy of blood-stage vaccines. In the second part, blood-stage vaccine candidates that showed some efficacy in human clinical trials or controlled human malaria infection models are discussed. Then, candidates under clinical investigation are described in the third part, and other novel candidates and strategies are reviewed in the last part.
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Affiliation(s)
- Kazutoyo Miura
- a Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
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24
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Draper SJ, Angov E, Horii T, Miller LH, Srinivasan P, Theisen M, Biswas S. Recent advances in recombinant protein-based malaria vaccines. Vaccine 2015; 33:7433-43. [PMID: 26458807 PMCID: PMC4687528 DOI: 10.1016/j.vaccine.2015.09.093] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 09/05/2015] [Accepted: 09/28/2015] [Indexed: 01/03/2023]
Abstract
Protein-based vaccines remain the cornerstone approach for B cell and antibody induction against leading target malaria antigens. Advances in antigen selection, immunogen design and epitope-focusing are advancing the field. New heterologous expression platforms are enabling cGMP production of next-generation protein vaccines. Next-generation antigens, protein-based immunogens and virus-like particle (VLP) delivery platforms are in clinical development. Protein-based vaccines will form part of a highly effective multi-component/multi-stage/multi-antigen subunit formulation against malaria.
Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle–including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed.
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Affiliation(s)
- Simon J Draper
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
| | - Evelina Angov
- Walter Reed Army Institute of Research, U. S. Military Malaria Research Program, Malaria Vaccine Branch, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 561-873, Japan
| | - Louis H Miller
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Prakash Srinivasan
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark; Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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Douglas AD, Baldeviano GC, Lucas CM, Lugo-Roman LA, Crosnier C, Bartholdson SJ, Diouf A, Miura K, Lambert LE, Ventocilla JA, Leiva KP, Milne KH, Illingworth JJ, Spencer AJ, Hjerrild KA, Alanine DGW, Turner AV, Moorhead JT, Edgel KA, Wu Y, Long CA, Wright GJ, Lescano AG, Draper SJ. A PfRH5-based vaccine is efficacious against heterologous strain blood-stage Plasmodium falciparum infection in aotus monkeys. Cell Host Microbe 2015; 17:130-9. [PMID: 25590760 PMCID: PMC4297294 DOI: 10.1016/j.chom.2014.11.017] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 09/11/2014] [Accepted: 11/13/2014] [Indexed: 12/22/2022]
Abstract
Antigenic diversity has posed a critical barrier to vaccine development against the pathogenic blood-stage infection of the human malaria parasite Plasmodium falciparum. To date, only strain-specific protection has been reported by trials of such vaccines in nonhuman primates. We recently showed that P. falciparum reticulocyte binding protein homolog 5 (PfRH5), a merozoite adhesin required for erythrocyte invasion, is highly susceptible to vaccine-inducible strain-transcending parasite-neutralizing antibody. In vivo efficacy of PfRH5-based vaccines has not previously been evaluated. Here, we demonstrate that PfRH5-based vaccines can protect Aotus monkeys against a virulent vaccine-heterologous P. falciparum challenge and show that such protection can be achieved by a human-compatible vaccine formulation. Protection was associated with anti-PfRH5 antibody concentration and in vitro parasite-neutralizing activity, supporting the use of this in vitro assay to predict the in vivo efficacy of future vaccine candidates. These data suggest that PfRH5-based vaccines have potential to achieve strain-transcending efficacy in humans. Vaccines based on the P. falciparum merozoite antigen PfRH5 were tested in Aotus monkeys PfRH5-based vaccines afforded protection against heterologous strains of P. falciparum Protection correlated with anti-PfRH5 IgG concentration and in vivo neutralization
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Affiliation(s)
| | | | - Carmen M Lucas
- US Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | | | | | | | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Rockville, MD 20852, USA
| | | | - Karina P Leiva
- US Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | | | | | | | | | | | | | | | | | - Yimin Wu
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Rockville, MD 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | | | | | - Simon J Draper
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
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Boes A, Spiegel H, Voepel N, Edgue G, Beiss V, Kapelski S, Fendel R, Scheuermayer M, Pradel G, Bolscher JM, Behet MC, Dechering KJ, Hermsen CC, Sauerwein RW, Schillberg S, Reimann A, Fischer R. Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate--Tackling the Cocktail Challenge. PLoS One 2015; 10:e0131456. [PMID: 26147206 PMCID: PMC4492585 DOI: 10.1371/journal.pone.0131456] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/02/2015] [Indexed: 11/30/2022] Open
Abstract
Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%). Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17–25 μg/ml), the blood stage (40–60 μg/ml) and the sexual stage (1.75 μg/ml). While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.
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Affiliation(s)
- Alexander Boes
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
- * E-mail:
| | - Nadja Voepel
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Gueven Edgue
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Veronique Beiss
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Stephanie Kapelski
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Rolf Fendel
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
- RWTH Aachen University, Institute of Molecular Biotechnology, Aachen, Germany
| | | | - Gabriele Pradel
- RWTH Aachen University, Institute of Molecular Biotechnology, Aachen, Germany
| | | | - Marije C. Behet
- Radboud university medical center, Nijmegen, The Netherlands
| | | | | | - Robert W. Sauerwein
- TropIQ Health Sciences, Nijmegen, The Netherlands
- Radboud university medical center, Nijmegen, The Netherlands
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Andreas Reimann
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany
- RWTH Aachen University, Institute of Molecular Biotechnology, Aachen, Germany
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Crystal structure of Plasmodium knowlesi apical membrane antigen 1 and its complex with an invasion-inhibitory monoclonal antibody. PLoS One 2015; 10:e0123567. [PMID: 25886591 PMCID: PMC4401722 DOI: 10.1371/journal.pone.0123567] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/05/2015] [Indexed: 11/30/2022] Open
Abstract
The malaria parasite Plasmodium knowlesi, previously associated only with infection of macaques, is now known to infect humans as well and has become a significant public health problem in Southeast Asia. This species should therefore be targeted in vaccine and therapeutic strategies against human malaria. Apical Membrane Antigen 1 (AMA1), which plays a role in Plasmodium merozoite invasion of the erythrocyte, is currently being pursued in human vaccine trials against P. falciparum. Recent vaccine trials in macaques using the P. knowlesi orthologue PkAMA1 have shown that it protects against infection by this parasite species and thus should be developed for human vaccination as well. Here, we present the crystal structure of Domains 1 and 2 of the PkAMA1 ectodomain, and of its complex with the invasion-inhibitory monoclonal antibody R31C2. The Domain 2 (D2) loop, which is displaced upon binding the Rhoptry Neck Protein 2 (RON2) receptor, makes significant contacts with the antibody. R31C2 inhibits binding of the Rhoptry Neck Protein 2 (RON2) receptor by steric blocking of the hydrophobic groove and by preventing the displacement of the D2 loop which is essential for exposing the complete binding site on AMA1. R31C2 recognizes a non-polymorphic epitope and should thus be cross-strain reactive. PkAMA1 is much less polymorphic than the P. falciparum and P. vivax orthologues. Unlike these two latter species, there are no polymorphic sites close to the RON2-binding site of PkAMA1, suggesting that P. knowlesi has not developed a mechanism of immune escape from the host’s humoral response to AMA1.
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Spiegel H, Boes A, Voepel N, Beiss V, Edgue G, Rademacher T, Sack M, Schillberg S, Reimann A, Fischer R. Application of a Scalable Plant Transient Gene Expression Platform for Malaria Vaccine Development. FRONTIERS IN PLANT SCIENCE 2015; 6:1169. [PMID: 26779197 PMCID: PMC4688378 DOI: 10.3389/fpls.2015.01169] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/07/2015] [Indexed: 05/23/2023]
Abstract
Despite decades of intensive research efforts there is currently no vaccine that provides sustained sterile immunity against malaria. In this context, a large number of targets from the different stages of the Plasmodium falciparum life cycle have been evaluated as vaccine candidates. None of these candidates has fulfilled expectations, and as long as we lack a single target that induces strain-transcending protective immune responses, combining key antigens from different life cycle stages seems to be the most promising route toward the development of efficacious malaria vaccines. After the identification of potential targets using approaches such as omics-based technology and reverse immunology, the rapid expression, purification, and characterization of these proteins, as well as the generation and analysis of fusion constructs combining different promising antigens or antigen domains before committing to expensive and time consuming clinical development, represents one of the bottlenecks in the vaccine development pipeline. The production of recombinant proteins by transient gene expression in plants is a robust and versatile alternative to cell-based microbial and eukaryotic production platforms. The transfection of plant tissues and/or whole plants using Agrobacterium tumefaciens offers a low technical entry barrier, low costs, and a high degree of flexibility embedded within a rapid and scalable workflow. Recombinant proteins can easily be targeted to different subcellular compartments according to their physicochemical requirements, including post-translational modifications, to ensure optimal yields of high quality product, and to support simple and economical downstream processing. Here, we demonstrate the use of a plant transient expression platform based on transfection with A. tumefaciens as essential component of a malaria vaccine development workflow involving screens for expression, solubility, and stability using fluorescent fusion proteins. Our results have been implemented for the evidence-based iterative design and expression of vaccine candidates combining suitable P. falciparum antigen domains. The antigens were also produced, purified, and characterized in further studies by taking advantage of the scalability of this platform.
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Affiliation(s)
- Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Alexander Boes
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
- *Correspondence: Alexander Boes
| | - Nadja Voepel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Veronique Beiss
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Gueven Edgue
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Thomas Rademacher
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Markus Sack
- Institute for Molecular Biotechnology, RWTH Aachen UniversityAachen, Germany
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Andreas Reimann
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IMEAachen, Germany
- Institute for Molecular Biotechnology, RWTH Aachen UniversityAachen, Germany
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Bioinformatic Identification of Peptidomimetic-Based Inhibitors against Plasmodium falciparum Antigen AMA1. Malar Res Treat 2014; 2014:642391. [PMID: 25580351 PMCID: PMC4281401 DOI: 10.1155/2014/642391] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/18/2014] [Indexed: 11/17/2022] Open
Abstract
Plasmodium falciparum apical membrane antigen 1 (PfAMA1) is a valuable vaccine candidate and exported on the merozoite surface at the time of erythrocyte invasion. PfAMA1 interacts with rhoptry neck protein PfRON2, a component of the rhoptry protein complex, which forms the tight junction at the time of invasion. Phage display studies have identified a 15-residue (F1) and a 20-residue (R1) peptide that bind to PfAMA1 and block the invasion of erythrocytes. Cocrystal structures of central region of PfAMA1 containing disulfide-linked clusters (domains I and II) with R1 peptide and a peptide derived from PfRON2 showed strong structural similarity in binding. The peptides bound to a hydrophobic groove surrounded by domain I and II loops. In this study, peptidomimetics based on the crucial PfAMA1-binding residues of PfRON2 peptide have been identified. Top 5 peptidomimetics when checked for their docking on the region of PfAMA1 encompassing the hydrophobic groove were found to dock on the groove. Drug-like molecules having structural similarity to the top 5 peptidomimetics were identified based on their binding ability to PfAMA1 hydrophobic groove in blind docking. These inhibitors provide potential lead compounds, which could be used in the development of antimalarials targeting PfAMA1.
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30
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Spiegel H, Schinkel H, Kastilan R, Dahm P, Boes A, Scheuermayer M, Chudobová I, Maskus D, Fendel R, Schillberg S, Reimann A, Fischer R. Optimization of a multi-stage, multi-subunit malaria vaccine candidate for the production in Pichia pastoris by the identification and removal of protease cleavage sites. Biotechnol Bioeng 2014; 112:659-67. [PMID: 25335451 DOI: 10.1002/bit.25481] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/09/2014] [Accepted: 10/14/2014] [Indexed: 01/21/2023]
Abstract
We demonstrated the successful optimization of a recombinant multi-subunit malaria vaccine candidate protein for production in the methylotrophic yeast Pichia pastoris by the identification and subsequent removal of two protease cleavage sites. After observing protein degradation in the culture supernatant of a fed-batch fermentation, the predominant proteolytic fragment of the secreted recombinant protein was analyzed by mass spectrometry. The MS data indicated the cleavage of an amino acid sequence matching the yeast KEX2-protease consensus motif EKRE. The cleavage in this region was completely abolished by the deletion of the EKRE motif in a modified variant. This modified variant was produced, purified, and used for immunization of rabbits, inducing high antigen specific antibody titers (2 × 10(6) ). Total IgG from rabbit immune sera recognized different stages of Plasmodium falciparum parasites in immunofluorescence assays, indicating native folding of the vaccine candidate. However, the modified variant was still degraded, albeit into different fragments. Further analysis by mass spectrometry and N-terminal sequencing revealed a second cleavage site downstream of the motif PEVK. We therefore removed a 17-amino-acid stretch including the PEVK motif, resulting in the subsequent production of the full-length recombinant vaccine candidate protein without significant degradation, with a yield of 53 mg per liter culture volume. We clearly demonstrate that the proteolytic degradation of recombinant proteins by endogenous P. pastoris proteases can be prevented by the identification and removal of such cleavage sites. This strategy is particularly relevant for the production of recombinant subunit vaccines, where product yield and stability play a more important role than for the production of a stringently-defined native sequence which is necessary for most therapeutic molecules.
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Affiliation(s)
- Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, Aachen, 52074, Germany.
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31
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Barry AE, Arnott A. Strategies for designing and monitoring malaria vaccines targeting diverse antigens. Front Immunol 2014; 5:359. [PMID: 25120545 PMCID: PMC4112938 DOI: 10.3389/fimmu.2014.00359] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/13/2014] [Indexed: 01/28/2023] Open
Abstract
After more than 50 years of intensive research and development, only one malaria vaccine candidate, “RTS,S,” has progressed to Phase 3 clinical trials. Despite only partial efficacy, this candidate is now forecast to become the first licensed malaria vaccine. Hence, more efficacious second-generation malaria vaccines that can significantly reduce transmission are urgently needed. This review will focus on a major obstacle hindering development of effective malaria vaccines: parasite antigenic diversity. Despite extensive genetic diversity in leading candidate antigens, vaccines have been and continue to be formulated using recombinant antigens representing only one or two strains. These vaccine strains represent only a small fraction of the diversity circulating in natural parasite populations, leading to escape of non-vaccine strains and challenging investigators’ abilities to measure strain-specific efficacy in vaccine trials. Novel strategies are needed to overcome antigenic diversity in order for vaccine development to succeed. Many studies have now cataloged the global diversity of leading Plasmodium falciparum and Plasmodium vivax vaccine antigens. In this review, we describe how population genetic approaches can be applied to this rich data source to predict the alleles that best represent antigenic diversity, polymorphisms that contribute to it, and to identify key polymorphisms associated with antigenic escape. We also suggest an approach to summarize the known global diversity of a given antigen to predict antigenic diversity, how to select variants that best represent the strains circulating in natural parasite populations and how to investigate the strain-specific efficacy of vaccine trials. Use of these strategies in the design and monitoring of vaccine trials will not only shed light on the contribution of genetic diversity to the antigenic diversity of malaria, but will also maximize the potential of future malaria vaccine candidates.
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Affiliation(s)
- Alyssa E Barry
- Division of Infection and Immunity, Walter and Eliza Hall Institute of Medical Research , Parkville, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Parkville, VIC , Australia
| | - Alicia Arnott
- Division of Infection and Immunity, Walter and Eliza Hall Institute of Medical Research , Parkville, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Parkville, VIC , Australia
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32
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Immunization with a functional protein complex required for erythrocyte invasion protects against lethal malaria. Proc Natl Acad Sci U S A 2014; 111:10311-6. [PMID: 24958881 DOI: 10.1073/pnas.1409928111] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
An essential step in the invasion of red blood cells (RBCs) by Plasmodium falciparum (Pf) merozoites is the binding of rhoptry neck protein 2 (RON2) to the hydrophobic groove of apical membrane antigen 1 (AMA1), triggering junction formation between the apical end of the merozoite and the RBC surface to initiate invasion. Vaccination with AMA1 provided protection against homologous parasites in one of two phase 2 clinical trials; however, despite its ability to induce high-titer invasion-blocking antibodies in a controlled human challenge trial, the vaccine conferred little protection even against the homologous parasite. Here we provide evidence that immunization with an AMA1-RON2 peptide complex, but not with AMA1 alone, provided complete protection against a lethal Plasmodium yoelii challenge in mice. Significantly, IgG from mice immunized with the complex transferred protection. Furthermore, IgG from PfAMA1-RON2-immunized animals showed enhanced invasion inhibition compared with IgG elicited by AMA1 alone. Interestingly, this qualitative increase in inhibitory activity appears to be related, at least in part, to a switch in the proportion of IgG specific for certain loop regions in AMA1 surrounding the binding site of RON2. Antibodies induced by the complex were not sufficient to block the FVO strain heterologous parasite, however, reinforcing the need to include multiallele AMA1 to cover polymorphisms. Our results suggest that AMA1 subunit vaccines may be highly effective when presented to the immune system as an invasion complex with RON2.
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33
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Elias SC, Choudhary P, de Cassan SC, Biswas S, Collins KA, Halstead FD, Bliss CM, Ewer KJ, Hodgson SH, Duncan CJA, Hill AVS, Draper SJ. Analysis of human B-cell responses following ChAd63-MVA MSP1 and AMA1 immunization and controlled malaria infection. Immunology 2014; 141:628-44. [PMID: 24303947 PMCID: PMC3956436 DOI: 10.1111/imm.12226] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/25/2013] [Accepted: 11/26/2013] [Indexed: 02/07/2023] Open
Abstract
Acquisition of non-sterilizing natural immunity to Plasmodium falciparum malaria has been shown in low transmission areas following multiple exposures. However, conflicting data from endemic areas suggest that the parasite may interfere with the induction of effective B-cell responses. To date, the impact of blood-stage parasite exposure on antigen-specific B cells has not been reported following controlled human malaria infection (CHMI). Here we analysed human B-cell responses in a series of Phase I/IIa clinical trials, which include CHMI, using candidate virus-vectored vaccines encoding two blood-stage antigens: merozoite surface protein 1 (MSP1) and apical membrane antigen 1 (AMA1). Previously vaccinated volunteers show boosting of pre-existing antigen-specific memory B-cell (mBC) responses following CHMI. In contrast, unvaccinated malaria-naive control volunteers developed an mBC response against MSP1 but not AMA1. Serum IgG correlated with the mBC response after booster vaccination but this relationship was less well maintained following CHMI. A significant reduction in peripheral MSP1-specific mBC was observed at the point of diagnosis of blood-stage infection. This was coincident with a reduction in peripheral blood B-cell subsets expressing CXCR3 and elevated serum levels of interferon-γ and CXCL9, suggesting migration away from the periphery. These CHMI data confirm that mBC and antibody responses can be induced and boosted by blood-stage parasite exposure, in support of epidemiological studies on low-level parasite exposure.
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Affiliation(s)
- Sean C Elias
- The Jenner Institute, University of Oxford, Oxford, UK
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34
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Cherian S, Wai Lam Y, McDaniels I, Struziak M, Delay RJ. Estradiol rapidly modulates odor responses in mouse vomeronasal sensory neurons. Neuroscience 2014; 269:43-58. [PMID: 24680884 DOI: 10.1016/j.neuroscience.2014.03.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/11/2014] [Accepted: 03/09/2014] [Indexed: 11/27/2022]
Abstract
In rodents, many social behaviors are driven by the sense of smell. The vomeronasal organ (VNO), part of the accessory olfactory system mediates many of these chemically driven behaviors. The VNO is heavily vascularized, and is readily accessible to circulating peptide or steroid hormones. Potentially, this allows circulating hormones to alter behavior through modulating the output of the primary sensory neurons in the VNO, the vomeronasal sensory neurons (VSNs). Based on this, we hypothesized that steroid hormones, in particular 17β-estradiol, would modulate activity of VSNs. In this paper, we show that the estrogen receptors, GPR30 and ERα, were present in VSNs and that estradiol may be synthesized locally in the VNO. Our results also showed that 17β-estradiol decreased responses of isolated VSNs to dilute urine, a potent natural stimulus, with respect to current amplitudes and depolarization. Further, 17β-estradiol increased the latency of the first action potential (AP) and the AP amplitude. Additionally, calcium responses to sulfated steroids (present in the low molecular weight fraction of urine) that act as ligands for apical vomeronasal receptors were decreased by 17β-estradiol. In conclusion, we show that estradiol modulates odorant responses mediated by VSNs and hence paves the way for future studies to better understand the mechanisms by which odorant mediated behavior is altered by endocrine status of the animal.
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Affiliation(s)
- S Cherian
- Department of Biology, University of Vermont, United States
| | - Y Wai Lam
- Department of Biology, University of Vermont, United States; Vermont Genetics Network Proteomics Facility, University of Vermont, United States
| | - I McDaniels
- Department of Biology, University of Vermont, United States
| | - M Struziak
- Department of Biology, University of Vermont, United States
| | - R J Delay
- Department of Biology, University of Vermont, United States.
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35
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Immunization with apical membrane antigen 1 confers sterile infection-blocking immunity against Plasmodium sporozoite challenge in a rodent model. Infect Immun 2013; 81:3586-99. [PMID: 23836827 DOI: 10.1128/iai.00544-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Apical membrane antigen 1 (AMA-1) is a leading blood-stage malaria vaccine candidate. Consistent with a key role in erythrocytic invasion, AMA-1-specific antibodies have been implicated in AMA-1-induced protective immunity. AMA-1 is also expressed in sporozoites and in mature liver schizonts where it may be a target of protective cell-mediated immunity. Here, we demonstrate for the first time that immunization with AMA-1 can induce sterile infection-blocking immunity against Plasmodium sporozoite challenge in 80% of immunized mice. Significantly higher levels of gamma interferon (IFN-γ)/interleukin-2 (IL-2)/tumor necrosis factor (TNF) multifunctional T cells were noted in immunized mice than in control mice. We also report the first identification of minimal CD8(+) and CD4(+) T cell epitopes on Plasmodium yoelii AMA-1. These data establish AMA-1 as a target of both preerythrocytic- and erythrocytic-stage protective immune responses and validate vaccine approaches designed to induce both cellular and humoral immunity.
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36
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Natural selection and population genetic structure of domain-I of Plasmodium falciparum apical membrane antigen-1 in India. INFECTION GENETICS AND EVOLUTION 2013; 18:247-56. [PMID: 23747831 DOI: 10.1016/j.meegid.2013.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/16/2013] [Accepted: 05/18/2013] [Indexed: 12/27/2022]
Abstract
Development of a vaccine against Plasmodium falciparum infection is an urgent priority particularly because of widespread resistance to most traditionally used drugs. Multiple evidences point to apical membrane antigen-1(AMA-1) as a prime vaccine candidate directed against P. falciparum asexual blood-stages. To gain understanding of the genetic and demographic forces shaping the parasite sequence diversity in Kolkata, a part of Pfama-1 gene covering domain-I was sequenced from 100 blood samples of malaria patients. Statistical and phylogenetic analyses of the sequences were performed using DnaSP and MEGA. Very high haplotype diversity was detected both at nucleotide (0.998±0.002) and amino-acid (0.996±0.001) levels. An abundance of low frequency polymorphisms (Tajima's D=-1.190, Fu & Li's D(∗) and F(∗)=-3.068 and -2.722), unimodal mismatch distribution and a star-like median-joining network of ama-1 haplotypes indicated a recent population expansion among Kolkata parasites. The high minimum number of recombination events (Rm=26) and a significantly high dN/dS of 3.705 (P<0.0001) in Kolkata suggested recombination and positive selection as major forces in the generation and maintenance of ama-1 allelic diversity. To evaluate the impact of observed non-synonymous substitutions in the context of AMA-1 functionality, PatchDock and FireDock protein-protein interaction solutions were mapped between PfAMA-1-PfRON2 and PfAMA-1-host IgNAR. Alterations in the desolvation and global energies of PfAMA-1-PfRON2 interaction complexes at the hotspot contact residues were observed together with redistribution of surface electrostatic potentials at the variant alleles with respect to referent Pf3D7 sequence. Finally, a comparison of P. falciparum subpopulations in five Indian regional isolates retrieved from GenBank revealed a significant level of genetic differentiation (FST=0.084-0.129) with respect to Kolkata sequences. Collectively, our results indicated a very high allelic and haplotype diversity, a high recombination rate and a signature of natural selection favoring accumulation of non-synonymous substitutions that facilitated PfAMA-1-PfRON2 interaction and hence parasite growth in Kolkata clinical isolates.
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Zakeri S, Sadeghi H, Mehrizi AA, Djadid ND. Population genetic structure and polymorphism analysis of gene encoding apical membrane antigen-1 (AMA-1) of Iranian Plasmodium vivax wild isolates. Acta Trop 2013; 126:269-79. [PMID: 23467011 DOI: 10.1016/j.actatropica.2013.02.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 02/14/2013] [Accepted: 02/20/2013] [Indexed: 11/27/2022]
Abstract
Plasmodium vivax apical membrane antigen-1 (PvAMA-1) is a major candidate antigen for human malaria vaccine. In the present study, polymorphism of pvama-1 among Iranian isolates was investigated to generate useful information on this vaccine candidate antigen, which is required for the rational design of a vaccine against P. vivax. Blood samples were collected from P. vivax-infected Iranian patients during 2009-2010. Of 99 collected isolates, 37 were analyzed for almost the entire pvama-1 gene using sequencing. The overall nucleotide diversity (π) was 0.00826 ± 0.0004 and the majority of polymorphic sites were identified in domain I (DI) of the pvama-1 gene. Neutrality analysis using Tajima's D, Fu and Li's D* and F* and McDonald Kreitman tests showed a significant positive departure from neutral substitution patterns, indicating a possible balancing selection across the entire ectodomain and DI sequences of pvama-1 gene. However, no evidence was found for the balancing selection in DII and DIII regions of Iranian PvAMA-1. Also, 29 haplotypes with different frequencies were identified and the overall haplotype diversity was 0.982 ± 0.012. Epitope mapping prediction of PvAMA-1 showed the potential B-cell epitopes across DI-DIII overlap with E145K, P210S, R249H, G253E, K352E, R438H and N445D mutations; however, no mutation has been found in intrinsically unstructured/disordered regions. The fixation index (Fst) estimation between Iran and the closest geographical sites such as India (0.0707) showed a slight geographical genetic differentiation; however, the Fst estimation between Iran and Thailand (0.1253) suggested a moderate geographical isolation. In summary, genetic investigation in pvama-1 among Iranian P. vivax isolates indicates that this antigen showed limited antigenic diversity and most of the detected mutations are located outside B-cell epitopes. Therefore, the present results have significant implications in understanding the nature of P. vivax population circulating in Iran as well as in providing useful information for malaria vaccine development based on this antigen.
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Affiliation(s)
- Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran 1316943551, Iran.
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38
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Mehrizi AA, Sepehri M, Karimi F, Djadid ND, Zakeri S. Population genetics, sequence diversity and selection in the gene encoding the Plasmodium falciparum apical membrane antigen 1 in clinical isolates from the south-east of Iran. INFECTION GENETICS AND EVOLUTION 2013; 17:51-61. [PMID: 23557839 DOI: 10.1016/j.meegid.2013.03.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 03/17/2013] [Accepted: 03/23/2013] [Indexed: 12/26/2022]
Abstract
The Plasmodium falciparum apical membrane antigen1 (AMA1) is a leading malaria vaccine candidate antigen. In the present investigation, for the first time, the almost full length of the ama1 gene covering domain I (DI), DII and DIII was PCR amplified and sequenced in 21 P. falciparum isolates collected from the southeastern parts of Iran. The result showed the low genetic diversity of Iranian PfAMA1 with 11 PfAMA1 haplotypes in which nine out of 11 haplotypes are novel and have been reported for the first time. The Iranian P. falciparum population indicated a moderate level of genetic differentiation. The difference among the rates of non-synonymous and synonymous mutations, Tajima's D and McDonald-Kreitman tests suggested that the diversity at DI is due to positive natural selection. In addition, recombination contributes to the diversity of Iranian PfAMA1 and this is supported by the decline of the linkage disequilibrium index R(2) with increasing the nucleotide distance. The highly polymorphic residues (positions: 187, 197, 200, 230 and 243) were polymorphic; however, most of the SNPs in non-polymorphic residues were conserved except the residue at position 395. Nevertheless, no mutation was found in the DII loop of the Iranian PfAMA1, indicating that it is subjected to purifying selection. In conclusion, the low genetic diversity in PfAMA1 among Iranian isolates supports and provides valuable information for the development of a PfAMA1-based malaria vaccine.
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MESH Headings
- Amino Acid Sequence
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Epitopes, B-Lymphocyte/chemistry
- Epitopes, B-Lymphocyte/immunology
- Evolution, Molecular
- Gene Frequency
- Genetic Variation
- Haplotypes
- Humans
- Iran
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/prevention & control
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Molecular Sequence Data
- Mutation
- Phylogeny
- Plasmodium falciparum/genetics
- Plasmodium falciparum/immunology
- Plasmodium falciparum/isolation & purification
- Polymorphism, Genetic
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Recombination, Genetic
- Selection, Genetic
- Sequence Analysis, DNA
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Affiliation(s)
- Akram Abouie Mehrizi
- Malaria and Vector Research Group, Biotechnology Research Center, Pasteur Institute of Iran, Tehran 1316943551, Iran
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39
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Chuang I, Sedegah M, Cicatelli S, Spring M, Polhemus M, Tamminga C, Patterson N, Guerrero M, Bennett JW, McGrath S, Ganeshan H, Belmonte M, Farooq F, Abot E, Banania JG, Huang J, Newcomer R, Rein L, Litilit D, Richie NO, Wood C, Murphy J, Sauerwein R, Hermsen CC, McCoy AJ, Kamau E, Cummings J, Komisar J, Sutamihardja A, Shi M, Epstein JE, Maiolatesi S, Tosh D, Limbach K, Angov E, Bergmann-Leitner E, Bruder JT, Doolan DL, King CR, Carucci D, Dutta S, Soisson L, Diggs C, Hollingdale MR, Ockenhouse CF, Richie TL. DNA prime/Adenovirus boost malaria vaccine encoding P. falciparum CSP and AMA1 induces sterile protection associated with cell-mediated immunity. PLoS One 2013; 8:e55571. [PMID: 23457473 PMCID: PMC3573028 DOI: 10.1371/journal.pone.0055571] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/24/2012] [Indexed: 12/25/2022] Open
Abstract
Background Gene-based vaccination using prime/boost regimens protects animals and humans against malaria, inducing cell-mediated responses that in animal models target liver stage malaria parasites. We tested a DNA prime/adenovirus boost malaria vaccine in a Phase 1 clinical trial with controlled human malaria infection. Methodology/Principal Findings The vaccine regimen was three monthly doses of two DNA plasmids (DNA) followed four months later by a single boost with two non-replicating human serotype 5 adenovirus vectors (Ad). The constructs encoded genes expressing P. falciparum circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1). The regimen was safe and well-tolerated, with mostly mild adverse events that occurred at the site of injection. Only one AE (diarrhea), possibly related to immunization, was severe (Grade 3), preventing daily activities. Four weeks after the Ad boost, 15 study subjects were challenged with P. falciparum sporozoites by mosquito bite, and four (27%) were sterilely protected. Antibody responses by ELISA rose after Ad boost but were low (CSP geometric mean titer 210, range 44–817; AMA1 geometric mean micrograms/milliliter 11.9, range 1.5–102) and were not associated with protection. Ex vivo IFN-γ ELISpot responses after Ad boost were modest (CSP geometric mean spot forming cells/million peripheral blood mononuclear cells 86, range 13–408; AMA1 348, range 88–1270) and were highest in three protected subjects. ELISpot responses to AMA1 were significantly associated with protection (p = 0.019). Flow cytometry identified predominant IFN-γ mono-secreting CD8+ T cell responses in three protected subjects. No subjects with high pre-existing anti-Ad5 neutralizing antibodies were protected but the association was not statistically significant. Significance The DNA/Ad regimen provided the highest sterile immunity achieved against malaria following immunization with a gene-based subunit vaccine (27%). Protection was associated with cell-mediated immunity to AMA1, with CSP probably contributing. Substituting a low seroprevalence vector for Ad5 and supplementing CSP/AMA1 with additional antigens may improve protection. Trial Registration ClinicalTrials.govNCT00870987.
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MESH Headings
- Adenoviruses, Human/genetics
- Adenoviruses, Human/immunology
- Adolescent
- Adult
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- CD8-Positive T-Lymphocytes/immunology
- Female
- Humans
- Immunity, Cellular
- Interferon-gamma/immunology
- Malaria Vaccines/adverse effects
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/therapeutic use
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Male
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Middle Aged
- Plasmodium falciparum/genetics
- Plasmodium falciparum/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Vaccines, DNA/adverse effects
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vaccines, DNA/therapeutic use
- Young Adult
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Affiliation(s)
- Ilin Chuang
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Martha Sedegah
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Susan Cicatelli
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Michele Spring
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Mark Polhemus
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Cindy Tamminga
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Noelle Patterson
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Melanie Guerrero
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Jason W. Bennett
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Shannon McGrath
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Harini Ganeshan
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Maria Belmonte
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Fouzia Farooq
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Esteban Abot
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Jo Glenna Banania
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Jun Huang
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Rhonda Newcomer
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Lisa Rein
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Dianne Litilit
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Nancy O. Richie
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Chloe Wood
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Jittawadee Murphy
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Robert Sauerwein
- Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | | | - Andrea J. McCoy
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Edwin Kamau
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - James Cummings
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Jack Komisar
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Awalludin Sutamihardja
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Meng Shi
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Judith E. Epstein
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Santina Maiolatesi
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Donna Tosh
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Keith Limbach
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Evelina Angov
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Elke Bergmann-Leitner
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | | | - Denise L. Doolan
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - C. Richter King
- GenVec, Inc., Gaithersburg, Maryland, United States of America
| | - Daniel Carucci
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Sheetij Dutta
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | | | - Carter Diggs
- USAID, Washington, D. C., United States of America
| | - Michael R. Hollingdale
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Christian F. Ockenhouse
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Thomas L. Richie
- US Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- * E-mail:
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40
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Drew DR, Hodder AN, Wilson DW, Foley M, Mueller I, Siba PM, Dent AE, Cowman AF, Beeson JG. Defining the antigenic diversity of Plasmodium falciparum apical membrane antigen 1 and the requirements for a multi-allele vaccine against malaria. PLoS One 2012; 7:e51023. [PMID: 23227229 PMCID: PMC3515520 DOI: 10.1371/journal.pone.0051023] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/29/2012] [Indexed: 11/19/2022] Open
Abstract
Apical Membrane Antigen 1 (AMA1) is a leading malaria vaccine candidate and a target of naturally-acquired human immunity. Plasmodium falciparum AMA1 is polymorphic and in vaccine trials it induces strain-specific protection. This antigenic diversity is a major roadblock to development of AMA1 as a malaria vaccine and understanding how to overcome it is essential. To assess how AMA1 antigenic diversity limits cross-strain growth inhibition, we assembled a panel of 18 different P. falciparum isolates which are broadly representative of global AMA1 sequence diversity. Antibodies raised against four well studied AMA1 alleles (W2Mef, 3D7, HB3 and FVO) were tested for growth inhibition of the 18 different P. falciparum isolates in growth inhibition assays (GIA). All antibodies demonstrated substantial cross-inhibitory activity against different isolates and a mixture of the four different AMA1 antibodies inhibited all 18 isolates tested, suggesting significant antigenic overlap between AMA1 alleles and limited antigenic diversity of AMA1. Cross-strain inhibition by antibodies was only moderately and inconsistently correlated with the level of sequence diversity between AMA1 alleles, suggesting that sequence differences are not a strong predictor of antigenic differences or the cross-inhibitory activity of anti-allele antibodies. The importance of the highly polymorphic C1-L region for inhibitory antibodies and potential vaccine escape was assessed by generating novel transgenic P. falciparum lines for testing in GIA. While the polymorphic C1-L epitope was identified as a significant target of some growth-inhibitory antibodies, these antibodies only constituted a minor proportion of the total inhibitory antibody repertoire, suggesting that the antigenic diversity of inhibitory epitopes is limited. Our findings support the concept that a multi-allele AMA1 vaccine would give broad coverage against the diversity of AMA1 alleles and establish new tools to define polymorphisms important for vaccine escape.
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Affiliation(s)
- Damien R. Drew
- The Burnet Institute for Medical Research and Public Health, Melbourne, Australia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Anthony N. Hodder
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Danny W. Wilson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | | | - Ivo Mueller
- The Burnet Institute for Medical Research and Public Health, Melbourne, Australia
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Peter M. Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Arlene E. Dent
- Centre for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Alan F. Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - James G. Beeson
- The Burnet Institute for Medical Research and Public Health, Melbourne, Australia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Microbiology, Monash University, Victoria, Australia
- * E-mail:
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41
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Ouattara A, Takala-Harrison S, Thera MA, Coulibaly D, Niangaly A, Saye R, Tolo Y, Dutta S, Heppner DG, Soisson L, Diggs CL, Vekemans J, Cohen J, Blackwelder WC, Dube T, Laurens MB, Doumbo OK, Plowe CV. Molecular basis of allele-specific efficacy of a blood-stage malaria vaccine: vaccine development implications. J Infect Dis 2012. [PMID: 23204168 DOI: 10.1093/infdis/jis709] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The disappointing efficacy of blood-stage malaria vaccines may be explained in part by allele-specific immune responses that are directed against polymorphic epitopes on blood-stage antigens. FMP2.1/AS02(A), a blood-stage candidate vaccine based on apical membrane antigen 1 (AMA1) from the 3D7 strain of Plasmodium falciparum, had allele-specific efficacy against clinical malaria in a phase II trial in Malian children. We assessed the cross-protective efficacy of the malaria vaccine and inferred which polymorphic amino acid positions in AMA1 were the targets of protective allele-specific immune responses. FMP2.1/AS02(A) had the highest efficacy against AMA1 alleles that were identical to the 3D7 vaccine-type allele at 8 highly polymorphic amino acid positions in the cluster 1 loop (c1L) but differed from 3D7 elsewhere in the molecule. Comparison of the incidence of vaccine-type alleles before and after vaccination in the malaria vaccine and control groups and examination of the patterns of allele change at polymorphic positions in consecutive malaria episodes suggest that the highly polymorphic amino acid position 197 in c1L was the most critical determinant of allele-specific efficacy. These results indicate that a multivalent AMA1 vaccine with broad efficacy could include only a limited set of key alleles of this extremely polymorphic antigen.
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Affiliation(s)
- Amed Ouattara
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, Bamako, Mali
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42
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ChAd63-MVA-vectored blood-stage malaria vaccines targeting MSP1 and AMA1: assessment of efficacy against mosquito bite challenge in humans. Mol Ther 2012; 20:2355-68. [PMID: 23089736 DOI: 10.1038/mt.2012.223] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1-results consistent with vaccine-induced pre-erythrocytic, rather than blood-stage, immunity. These data call into question the utility of T cell-inducing blood-stage malaria vaccines and suggest that the focus should remain on high-titer antibody induction against susceptible antigen targets.
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43
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Ellis RD, Wu Y, Martin LB, Shaffer D, Miura K, Aebig J, Orcutt A, Rausch K, Zhu D, Mogensen A, Fay MP, Narum DL, Long C, Miller L, Durbin AP. Phase 1 study in malaria naïve adults of BSAM2/Alhydrogel®+CPG 7909, a blood stage vaccine against P. falciparum malaria. PLoS One 2012; 7:e46094. [PMID: 23056238 PMCID: PMC3464250 DOI: 10.1371/journal.pone.0046094] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 08/27/2012] [Indexed: 11/25/2022] Open
Abstract
A Phase 1 dose escalating study was conducted in malaria naïve adults to assess the safety, reactogenicity, and immunogenicity of the blood stage malaria vaccine BSAM2/Alhydrogel®+ CPG 7909. BSAM2 is a combination of the FVO and 3D7 alleles of recombinant AMA1 and MSP142, with equal amounts by weight of each of the four proteins mixed, bound to Alhydrogel®, and administered with the adjuvant CPG 7909. Thirty (30) volunteers were enrolled in two dose groups, with 15 volunteers receiving up to three doses of 40 µg total protein at Days 0, 56, and 180, and 15 volunteers receiving up to three doses of 160 µg protein on the same schedule. Most related adverse events were mild or moderate, but 4 volunteers experienced severe systemic reactions and two were withdrawn from vaccinations due to adverse events. Geometric mean antibody levels after two vaccinations with the high dose formulation were 136 µg/ml for AMA1 and 78 µg/ml for MSP142. Antibody responses were not significantly different in the high dose versus low dose groups and did not further increase after third vaccination. In vitro growth inhibition was demonstrated and was closely correlated with anti-AMA1 antibody responses. A Phase 1b trial in malaria-exposed adults is being conducted.
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Affiliation(s)
- Ruth D. Ellis
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Yimin Wu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
- * E-mail:
| | - Laura B. Martin
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Donna Shaffer
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Kazutoyo Miura
- Biostatistics Research Branch, NIAID/NIH, Rockville, Maryland, United States of America
| | - Joan Aebig
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Andrew Orcutt
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Kelly Rausch
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Daming Zhu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Anders Mogensen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Michael P. Fay
- Biostatistics Research Branch, NIAID/NIH, Rockville, Maryland, United States of America
| | - David L. Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Carole Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, Maryland, United States of America
| | - Louis Miller
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID/NIH), Rockville, Maryland, United States of America
| | - Anna P. Durbin
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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44
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Richie TL. Malaria vaccines for travelers. Travel Med Infect Dis 2012; 2:193-210. [PMID: 17291981 DOI: 10.1016/j.tmaid.2004.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Accepted: 07/07/2004] [Indexed: 11/21/2022]
Affiliation(s)
- Thomas L Richie
- Naval Medical Research Center Malaria Program, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA
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45
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Kusi KA, Dodoo D, Bosomprah S, van der Eijk M, Faber BW, Kocken CHM, Remarque EJ. Measurement of the plasma levels of antibodies against the polymorphic vaccine candidate apical membrane antigen 1 in a malaria-exposed population. BMC Infect Dis 2012; 12:32. [PMID: 22299616 PMCID: PMC3317819 DOI: 10.1186/1471-2334-12-32] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 02/02/2012] [Indexed: 11/24/2022] Open
Abstract
Background Establishing antibody correlates of protection against malaria in human field studies and clinical trials requires, amongst others, an accurate estimation of antibody levels. For polymorphic antigens such as apical membrane antigen 1 (AMA1), this may be confounded by the occurrence of a large number of allelic variants in nature. Methods To test this hypothesis, plasma antibody levels in an age-stratified cohort of naturally exposed children from a malaria-endemic area in Southern Ghana were determined by indirect ELISA. Titres against four single PfAMA1 alleles were compared with those against three different allele mixtures presumed to have a wider repertoire of epitope specificities. Associations of antibody levels with the incidence of clinical malaria as well as with previous exposure to parasites were also examined. Results Antibody titres against PfAMA1 alleles generally increased with age/exposure while antibody specificity for PfAMA1 variants decreased, implying that younger children (≤ 5 years) elicit a more strain-specific antibody response compared to older children. Antibody titre measurements against the FVO and 3D7 AMA1 alleles gave the best titre estimates as these varied least in pair-wise comparisons with titres against all PfAMA1 allele mixtures. There was no association between antibody levels against any capture antigen and either clinical malaria incidence or parasite density. Conclusions The current data shows that levels of naturally acquired antigen-specific antibodies, especially in infants and young children, are dependent on the antigenic allele used for measurement. This may be relevant to the interpretation of antibody titre data from measurements against single PfAMA1 alleles, especially in studies involving infants and young children who have experienced fewer infections.
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Affiliation(s)
- Kwadwo A Kusi
- Department of Parasitology, Biomedical Primate Research Centre, Postbox 3306, 2280, GH Rijswijk, The Netherlands.
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46
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Motevalli Haghi A, Nateghpour M, Edrissian G, Sepehrizadeh Z, Mohebali M, Khoramizade MR, Shahrbabak SS, Moghimi H. Sequence Analysis of Different Domains of Plasmodium vivax Apical Membrane Antigen (PvAMA-1 gene) Locus in Iran. IRANIAN JOURNAL OF PARASITOLOGY 2012; 7:26-31. [PMID: 23133468 PMCID: PMC3488817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 01/21/2012] [Indexed: 11/15/2022]
Abstract
BACKGROUND Plasmodium vivax is responsible for approximately 80 million malaria cases in the world. Apical membrane antigen1 (AMA-1) is a type I integral membrane protein present in all Plasmodium species. AMA-1 interferes in critical steps of invasion of human hepatocytes by sporozoites and red blood cells by merozoites and is one of the most immunodominant antigens for eliciting a protective immune response in human. It is considered as a promising antigen for inclusion in a vaccine against P. vivax. Since more knowledge is needed to lighten the scope of such antigen we compared genetic variation in P. vivax AMA-1from an Iranian isolate with those reported from some of the other malarious countries so far. METHODS P. vivax genomic DNA was extracted from the whole blood of an Iranian patient with patent P. vivax infection. The nucleotide sequence for 446 amino acid (AA) residues (42-488 of PvAMA-1) was amplified by PCR and cloned in pUC19 vector for sequencing. RESULTS Sequence analysis of the antigen showed a high degree of identity (99%) with strong homology to the PvAMA-1 gene of P. vivax S3 and SKO814 isolates from India and Korea (Asian isolates) respectively, and 96% similarity with P. vivax Sal-1 AMA-1 gene from El Salvador. CONCLUSIONS We cloned and characterized three domains of PvAMA-1 gene from an Iranian patient. Predicted protein sequence of this gene showed some discrepancies in corresponding protein in comparing with similar genes reported from other malarious countries.
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Affiliation(s)
- A Motevalli Haghi
- Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - M Nateghpour
- Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences, Tehran, Iran,Corresponding author:Tel: +982188989130, E-mail:
| | - GhH Edrissian
- Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences, Tehran, Iran
| | - Z Sepehrizadeh
- Dept. of Pharmaceutical Biotechnology, Pharmacy faculty, Tehran University of Medical Sciences, Tehran, Iran
| | - M Mohebali
- Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - MR Khoramizade
- Dept. of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - S Sabouri Shahrbabak
- Dept. of Pharmaceutical Biotechnology, Pharmacy faculty, Tehran University of Medical Sciences, Tehran, Iran
| | - H Moghimi
- Dept. of Microbiology, Faculty of Biology, Tehran University, Tehran, Iran
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47
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Sedegah M, Tamminga C, McGrath S, House B, Ganeshan H, Lejano J, Abot E, Banania GJ, Sayo R, Farooq F, Belmonte M, Manohar N, Richie NO, Wood C, Long CA, Regis D, Williams FT, Shi M, Chuang I, Spring M, Epstein JE, Mendoza-Silveiras J, Limbach K, Patterson NB, Bruder JT, Doolan DL, King CR, Soisson L, Diggs C, Carucci D, Dutta S, Hollingdale MR, Ockenhouse CF, Richie TL. Adenovirus 5-vectored P. falciparum vaccine expressing CSP and AMA1. Part A: safety and immunogenicity in seronegative adults. PLoS One 2011; 6:e24586. [PMID: 22003383 PMCID: PMC3189181 DOI: 10.1371/journal.pone.0024586] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 08/15/2011] [Indexed: 11/24/2022] Open
Abstract
Background Models of immunity to malaria indicate the importance of CD8+ T cell responses for targeting intrahepatic stages and antibodies for targeting sporozoite and blood stages. We designed a multistage adenovirus 5 (Ad5)-vectored Plasmodium falciparum malaria vaccine, aiming to induce both types of responses in humans, that was tested for safety and immunogenicity in a Phase 1 dose escalation trial in Ad5-seronegative volunteers. Methodology/Principal Findings The NMRC-M3V-Ad-PfCA vaccine combines two adenovectors encoding circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1). Group 1 (n = 6) healthy volunteers received one intramuscular injection of 2×10∧10 particle units (1×10∧10 each construct) and Group 2 (n = 6) a five-fold higher dose. Transient, mild to moderate adverse events were more pronounced with the higher dose. ELISpot responses to CSP and AMA1 peaked at 1 month, were higher in the low dose (geomean CSP = 422, AMA1 = 862 spot forming cells/million) than in the high dose (CSP = 154, p = 0.049, AMA1 = 423, p = 0.045) group and were still positive at 12 months in a number of volunteers. ELISpot depletion assays identified dependence on CD4+ or on both CD4+ and CD8+ T cells, with few responses dependent only on CD8+ T cells. Intracellular cytokine staining detected stronger CD8+ than CD4+ T cell IFN-γ responses (CSP p = 0.0001, AMA1 p = 0.003), but similar frequencies of multifunctional CD4+ and CD8+ T cells secreting two or more of IFN-γ, TNF-α or IL-2. Median fluorescence intensities were 7–10 fold higher in triple than single secreting cells. Antibody responses were low but trended higher in the high dose group and did not inhibit growth of cultured P. falciparum blood stage parasites. Significance As found in other trials, adenovectored vaccines appeared safe and well-tolerated at doses up to 1×10∧11 particle units. This is the first demonstration in humans of a malaria vaccine eliciting strong CD8+ T cell IFN-γ responses. Trial Registration ClinicalTrials.govNCT00392015
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Affiliation(s)
- Martha Sedegah
- U.S. Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America.
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Kusi KA, Remarque EJ, Riasat V, Walraven V, Thomas AW, Faber BW, Kocken CHM. Safety and immunogenicity of multi-antigen AMA1-based vaccines formulated with CoVaccine HT™ and Montanide ISA 51 in rhesus macaques. Malar J 2011; 10:182. [PMID: 21726452 PMCID: PMC3142537 DOI: 10.1186/1475-2875-10-182] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/04/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increasing the breadth of the functional antibody response through immunization with Plasmodium falciparum apical membrane antigen 1 (PfAMA1) multi-allele vaccine formulations has been demonstrated in several rodent and rabbit studies. This study assesses the safety and immunogenicity of three PfAMA1 Diversity-Covering (DiCo) vaccine candidates formulated as an equimolar mixture (DiCo mix) in CoVaccine HT™ or Montanide ISA 51, as well as that of a PfAMA1-MSP1₁₉ fusion protein formulated in Montanide ISA 51. METHODS Vaccine safety in rhesus macaques was monitored by animal behaviour observation and assessment of organ and systemic functions through clinical chemistry and haematology measurements. The immunogenicity of vaccine formulations was assessed by enzyme-linked immunosorbent assays and in vitro parasite growth inhibition assays with three culture-adapted P. falciparum strains. RESULTS These data show that both adjuvants were well tolerated with only transient changes in a few of the chemical and haematological parameters measured. DiCo mix formulated in CoVaccine HT™ proved immunologically and functionally superior to the same candidate formulated in Montanide ISA 51. Immunological data from the fusion protein candidate was however difficult to interpret as four out of six immunized animals were non-responsive for unknown reasons. CONCLUSIONS The study highlights the safety and immunological benefits of DiCo mix as a potential human vaccine against blood stage malaria, especially when formulated in CoVaccine HT™, and adds to the accumulating data on the specificity broadening effects of DiCo mix.
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Affiliation(s)
- Kwadwo A Kusi
- Department of Parasitology, Biomedical Primate Research Centre, Postbox 3306, 2280 GH, Rijswijk, The Netherlands
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Identification of a highly antigenic linear B cell epitope within Plasmodium vivax apical membrane antigen 1 (AMA-1). PLoS One 2011; 6:e21289. [PMID: 21713006 PMCID: PMC3119695 DOI: 10.1371/journal.pone.0021289] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/25/2011] [Indexed: 12/21/2022] Open
Abstract
Apical membrane antigen 1 (AMA-1) is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1) have shown a higher prevalence of specific antibodies to domain II (DII) of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs). The B cell epitope comprising the amino acid sequence 290–307 of PvAMA-1 (SASDQPTQYEEEMTDYQK), with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both), respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.
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50
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Miura K, Perera S, Brockley S, Zhou H, Aebig JA, Moretz SE, Miller LH, Doumbo OK, Sagara I, Dicko A, Ellis RD, Long CA. Non-apical membrane antigen 1 (AMA1) IgGs from Malian children interfere with functional activity of AMA1 IgGs as judged by growth inhibition assay. PLoS One 2011; 6:e20947. [PMID: 21695140 PMCID: PMC3113848 DOI: 10.1371/journal.pone.0020947] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/13/2011] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Apical membrane antigen 1 (AMA1) is one of the best-studied blood-stage malaria vaccine candidates. When an AMA1 vaccine was tested in a malaria naïve population, it induced functionally active antibodies judged by Growth Inhibition Assay (GIA). However, the same vaccine failed to induce higher growth-inhibitory activity in adults living in a malaria endemic area. Vaccination did induce functionally active antibodies in malaria-exposed children with less than 20% inhibition in GIA at baseline, but not in children with more than that level of baseline inhibition. METHODS Total IgGs were purified from plasmas collected from the pediatric trial before and after immunization and pools of total IgGs were made. Another set of total IgGs was purified from U.S. adults immunized with AMA1 (US-total IgG). From these total IgGs, AMA1-specific and non-AMA1 IgGs were affinity purified and the functional activity of these IgGs was evaluated by GIA. Competition ELISA was performed with the U.S.-total IgG and non-AMA1 IgGs from malaria-exposed children. RESULTS AMA1-specific IgGs from malaria-exposed children and U.S. vaccinees showed similar growth-inhibitory activity at the same concentrations. When mixed with U.S.-total IgG, non-AMA1 IgGs from children showed an interference effect in GIA. Interestingly, the interference effect was higher with non-AMA1 IgGs from higher titer pools. The non-AMA1 IgGs did not compete with anti-AMA1 antibody in U.S.-total IgG in the competition ELISA. CONCLUSION Children living in a malaria endemic area have a fraction of IgGs that interferes with the biological activity of anti-AMA1 antibody as judged by GIA. While the mechanism of interference is not resolved in this study, these results suggest it is not caused by direct competition between non-AMA1 IgG and AMA1 protein. This study indicates that anti-malaria IgGs induced by natural exposure may interfere with the biological effect of antibody induced by an AMA1-based vaccine in the target population.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (KM); (CAL)
| | - Suwani Perera
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Sarah Brockley
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Hong Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Joan A. Aebig
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Samuel E. Moretz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Louis H. Miller
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ogobara K. Doumbo
- Malaria Research and Training Center, Faculty of Medicine Pharmacy and Dentistry, University of Bamako, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Center, Faculty of Medicine Pharmacy and Dentistry, University of Bamako, Bamako, Mali
| | - Alassane Dicko
- Malaria Research and Training Center, Faculty of Medicine Pharmacy and Dentistry, University of Bamako, Bamako, Mali
| | - Ruth D. Ellis
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (KM); (CAL)
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