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Kusi KA, Amoah LE, Acquah FK, Ennuson NA, Frempong AF, Ofori EA, Akyea-Mensah K, Kyei-Baafour E, Osei F, Frimpong A, Singh SK, Theisen M, Remarque EJ, Faber BW, Belmonte M, Ganeshan H, Huang J, Villasante E, Sedegah M. Plasmodium falciparum AMA1 and CSP antigen diversity in parasite isolates from southern Ghana. Front Cell Infect Microbiol 2024; 14:1375249. [PMID: 38808064 PMCID: PMC11132687 DOI: 10.3389/fcimb.2024.1375249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/19/2024] [Indexed: 05/30/2024] Open
Abstract
Introduction Diversity in malarial antigens is an immune evasion mechanism that gives malaria parasites an edge over the host. Immune responses against one variant of a polymorphic antigen are usually not fully effective against other variants due to altered epitopes. This study aimed to evaluate diversity in the Plasmodium falciparum antigens apical membrane antigen 1 (PfAMA1) and circumsporozoite protein (PfCSP) from circulating parasites in a malaria-endemic community in southern Ghana and to determine the effects of polymorphisms on antibody response specificity. Methods The study involved 300 subjects, whose P. falciparum infection status was determined by microscopy and PCR. Diversity within the two antigens was evaluated by msp2 gene typing and molecular gene sequencing, while the host plasma levels of antibodies against PfAMA1, PfCSP, and two synthetic 24mer peptides from the conserved central repeat region of PfCSP, were measured by ELISA. Results Of the 300 subjects, 171 (57%) had P. falciparum infection, with 165 of the 171 (96.5%) being positive for either or both of the msp2 allelic families. Gene sequencing of DNA from 55 clonally infected samples identified a total of 56 non-synonymous single nucleotide polymorphisms (SNPs) for the Pfama1 gene and these resulted in 44 polymorphic positions, including two novel positions (363 and 365). Sequencing of the Pfcsp gene from 69 clonal DNA samples identified 50 non-synonymous SNPs that resulted in 42 polymorphic positions, with half (21) of these polymorphic positions being novel. Of the measured antibodies, only anti-PfCSP antibodies varied considerably between PCR parasite-positive and parasite-negative persons. Discussion These data confirm the presence of a considerable amount of unique, previously unreported amino acid changes, especially within PfCSP. Drivers for this diversity in the Pfcsp gene do not immediately seem apparent, as immune pressure will be expected to drive a similar level of diversity in the Pfama1 gene.
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Affiliation(s)
- Kwadwo A. Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Linda E. Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Festus Kojo Acquah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Nana Aba Ennuson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Abena F. Frempong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Ebenezer A. Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo Akyea-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Frank Osei
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Augustina Frimpong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Susheel K. Singh
- Center for Medical Parasitology at the Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Congenital Diseases, Statens Serum Institut, Copenhagen, Denmark
| | - Michael Theisen
- Center for Medical Parasitology at the Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Congenital Diseases, Statens Serum Institut, Copenhagen, Denmark
| | - Edmond J. Remarque
- Department of Parasitology, Biomedical Primate Research Center, Rijswijk, Netherlands
| | - Bart W. Faber
- Department of Parasitology, Biomedical Primate Research Center, Rijswijk, Netherlands
| | - Maria Belmonte
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Malaria Department, Naval Medical Research Command, Silver Spring, MD, United States
| | - Harini Ganeshan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Malaria Department, Naval Medical Research Command, Silver Spring, MD, United States
| | - Jun Huang
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Malaria Department, Naval Medical Research Command, Silver Spring, MD, United States
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Command, Silver Spring, MD, United States
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Command, Silver Spring, MD, United States
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2
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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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Paica IC, Rusu I, Popescu O, Brînzan A, Pencea I, Dobrinescu C, Kelemen B. Tentative indicators of malaria in archaeological skeletal samples, a pilot study testing different methods. INTERNATIONAL JOURNAL OF PALEOPATHOLOGY 2023; 40:109-116. [PMID: 36724549 DOI: 10.1016/j.ijpp.2023.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
OBJECTIVE This study attempts to integrate multiple methods to investigate the presence of malaria in human skeletal samples from an archaeological context. MATERIALS 33 well preserved human remains originating from a 17th-century archaeological site in southeastern Romania. METHODS The human bone samples were analyzed using rapid diagnostic tests for malaria antigens and PCR amplification of Plasmodium falciparum apical membrane antigen 1. A preliminary test was performed to identify and briefly characterize the presence of hemozoin using a combination of TEM imaging and diffraction. RESULTS The rapid diagnostic tests indicated that more than half of the examined samples were positive for Plasmodium antigens, but no traces of the parasites' genetic material were detected despite repeated attempts. The TEM images indicated that hemozoin might be a promising diagnostic marker of malaria in ancient bones. CONCLUSIONS The indisputable identification of malaria in the analyzed archaeological population was not possible as none of the applied methodological strategies turned out to be straightforward. SIGNIFICANCE This study reinforces the intricacy and limitations of unequivocally identifying malaria in past populations and sets the stage for future studies on such life-threatening infectious disease in a geographical space, which is currently underrepresented in the bioarchaeological literature. LIMITATIONS The low sample size and the lack of consistency across all assays hindered understanding the role of malaria in the studied population. SUGGESTIONS FOR FURTHER RESEARCH Further thorough multidisciplinary approaches on malaria detection in ancient settlements would be appropriate to inform our knowledge of its origins, frequency, and pathogen changes over centuries.
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Affiliation(s)
| | - Ioana Rusu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, 400006, Romania; Molecular Biology Centre, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeș-Bolyai University, Cluj-Napoca, 400271, Romania.
| | - Octavian Popescu
- Institute of Biology Bucharest of Romanian Academy, Bucharest, 060031, Romania; Molecular Biology Centre, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeș-Bolyai University, Cluj-Napoca, 400271, Romania; Emil G. Racoviță Institute, Babeș-Bolyai University, Cluj-Napoca, 400006, Romania
| | - Alexandru Brînzan
- Institute of Biology Bucharest of Romanian Academy, Bucharest, 060031, Romania
| | - Ion Pencea
- Department of Metallic Material Science and Physical Metallurgy, University Politehnica of Bucharest, Bucharest, 060042, Romania
| | - Cătălin Dobrinescu
- Department of Research-Development and Projects, Museum of National History and Archaeology, Constanţa, 900745, Romania
| | - Beatrice Kelemen
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, 400006, Romania; Molecular Biology Centre, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeș-Bolyai University, Cluj-Napoca, 400271, Romania
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Ng YL, Lee WC, Lau YL, Fong MY. The Impact of Geographical Variation in Plasmodium knowlesi Apical Membrane Protein 1 (PkAMA-1) on Invasion Dynamics of P. knowlesi. Trop Med Infect Dis 2023; 8:tropicalmed8010056. [PMID: 36668963 PMCID: PMC9863575 DOI: 10.3390/tropicalmed8010056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/16/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023] Open
Abstract
Plasmodium knowlesi has emerged as an important zoonotic parasite that causes persistent symptomatic malaria in humans. The signs and symptoms of malaria are attributed to the blood stages of the parasites, which start from the invasion of erythrocytes by the blood stage merozoites. The apical membrane protein 1 (AMA-1) plays an important role in the invasion. In this study, we constructed and expressed recombinant PkAMA-1 domain II (PkAMA-1-DII) representing the predominant haplotypes from Peninsular Malaysia and Malaysian Borneo and raised specific antibodies against the recombinant proteins in rabbits. Despite the minor amino acid sequence variation, antibodies raised against haplotypes from Peninsular Malaysia and Malaysian Borneo demonstrated different invasion inhibition (46.81% and 39.45%, respectively) to P. knowlesi A1-H.1, a reference strain derived from Peninsular Malaysia. Here, we demonstrated how a minor variation in a conserved parasite protein could cast a significant impact on parasite invasion biology, suggesting a complex host-switching of P. knowlesi from different locations. This may challenge the implementation of a standardized One Health approach against the transmission of knowlesi malaria.
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Affiliation(s)
- Yee Ling Ng
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence:
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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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6
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Biswas A, Raran-Kurussi S, Narayan A, Kar A, Chandra Mashurabad P, Bhattacharyya MK, Mandal K. Efficient refolding and functional characterization of PfAMA1(DI+DII) expressed in E. coli. Biochem Biophys Rep 2021; 26:100950. [PMID: 33665380 PMCID: PMC7907217 DOI: 10.1016/j.bbrep.2021.100950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/18/2021] [Accepted: 02/04/2021] [Indexed: 11/30/2022] Open
Abstract
Apical membrane antigen 1 (AMA1) is a surface protein of Plasmodium sp. that plays a crucial role in forming moving junction (MJ) during the invasion of human red blood cells. The obligatory presence of AMA1 in the parasite lifecycle designates this protein as a potential vaccine candidate and an essential target for the development of novel peptide or protein therapeutics. However, due to multiple cysteine residues in the protein sequence, attaining the native fold with correct disulfide linkages during the refolding process after expression in bacteria has remained challenging for years. Although several approaches to obtain the refolded protein from bacterial expression have been reported previously, achieving high yield during refolding and proper functional validation of the expressed protein was lacking. We report here an improved method of refolding to obtain higher quantity of refolded protein. We have also validated the refolded protein's functional activity by evaluating the expressed AMA1 protein binding with a known inhibitory peptide, rhoptry neck protein 2 (RON2), using surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). A simple yet effective protocol for P. falciparum AMA1 protein expression from E. coli. Highly reproducible and scalable refolding protocol. The modified refolding method uses a step-wise dialysis technique. Functional validation of the refolded protein shown by binding with PfRON2 ectodomain using SPR and ITC.
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Affiliation(s)
- Anamika Biswas
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Sreejith Raran-Kurussi
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Akash Narayan
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Abhisek Kar
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Purna Chandra Mashurabad
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana 500046, India
| | - Mrinal Kanti Bhattacharyya
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana 500046, India
| | - Kalyaneswar Mandal
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
- Corresponding author.
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7
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Bailey JA, Berry AA, Travassos MA, Ouattara A, Boudova S, Dotsey EY, Pike A, Jacob CG, Adams M, Tan JC, Bannen RM, Patel JJ, Pablo J, Nakajima R, Jasinskas A, Dutta S, Takala-Harrison S, Lyke KE, Laurens MB, Niangaly A, Coulibaly D, Kouriba B, Doumbo OK, Thera MA, Felgner PL, Plowe CV. Microarray analyses reveal strain-specific antibody responses to Plasmodium falciparum apical membrane antigen 1 variants following natural infection and vaccination. Sci Rep 2020; 10:3952. [PMID: 32127565 PMCID: PMC7054363 DOI: 10.1038/s41598-020-60551-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 02/13/2020] [Indexed: 11/30/2022] Open
Abstract
Vaccines based on Plasmodium falciparum apical membrane antigen 1 (AMA1) have failed due to extensive polymorphism in AMA1. To assess the strain-specificity of antibody responses to malaria infection and AMA1 vaccination, we designed protein and peptide microarrays representing hundreds of unique AMA1 variants. Following clinical malaria episodes, children had short-lived, sequence-independent increases in average whole-protein seroreactivity, as well as strain-specific responses to peptides representing diverse epitopes. Vaccination resulted in dramatically increased seroreactivity to all 263 AMA1 whole-protein variants. High-density peptide analysis revealed that vaccinated children had increases in seroreactivity to four distinct epitopes that exceeded responses to natural infection. A single amino acid change was critical to seroreactivity to peptides in a region of AMA1 associated with strain-specific vaccine efficacy. Antibody measurements using whole antigens may be biased towards conserved, immunodominant epitopes. Peptide microarrays may help to identify immunogenic epitopes, define correlates of vaccine protection, and measure strain-specific vaccine-induced antibodies.
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Affiliation(s)
- Jason A Bailey
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrea A Berry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark A Travassos
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amed Ouattara
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sarah Boudova
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Emmanuel Y Dotsey
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA
| | - Andrew Pike
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - John C Tan
- Previous address: Roche Sequencing Solutions, Madison, WI, USA
- Nimble Therapeutics, Madison, WI, USA
| | - Ryan M Bannen
- Previous address: Roche Sequencing Solutions, Madison, WI, USA
- Nimble Therapeutics, Madison, WI, USA
| | - Jigar J Patel
- Previous address: Roche Sequencing Solutions, Madison, WI, USA
- Nimble Therapeutics, Madison, WI, USA
| | - Jozelyn Pablo
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA
| | - Rie Nakajima
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA
| | - Algis Jasinskas
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA
| | - Sheetij Dutta
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mahamadou A Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Philip L Felgner
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA
| | - Christopher V Plowe
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
- Duke Global Health Institute, Duke University, Durham, NC, USA.
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8
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Salamanca DR, Gómez M, Camargo A, Cuy-Chaparro L, Molina-Franky J, Reyes C, Patarroyo MA, Patarroyo ME. Plasmodium falciparum Blood Stage Antimalarial Vaccines: An Analysis of Ongoing Clinical Trials and New Perspectives Related to Synthetic Vaccines. Front Microbiol 2019; 10:2712. [PMID: 31849871 PMCID: PMC6901501 DOI: 10.3389/fmicb.2019.02712] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/08/2019] [Indexed: 01/10/2023] Open
Abstract
Plasmodium falciparum malaria is a disease causing high morbidity and mortality rates worldwide, mainly in sub-Saharan Africa. Candidates have been identified for vaccines targeting the parasite's blood stage; this stage is important in the development of symptoms and clinical complications. However, no vaccine that can directly affect morbidity and mortality rates is currently available. This review analyzes the formulation, methodological design, and results of active clinical trials for merozoite-stage vaccines, regarding their safety profile, immunological response (phase Ia/Ib), and protective efficacy levels (phase II). Most vaccine candidates are in phase I trials and have had an acceptable safety profile. GMZ2 has made the greatest progress in clinical trials; its efficacy has been 14% in children aged less than 5 years in a phase IIb trial. Most of the available candidates that have shown strong immunogenicity and that have been tested for their protective efficacy have provided good results when challenged with a homologous parasite strain; however, their efficacy has dropped when they have been exposed to a heterologous strain. In view of these vaccines' unpromising results, an alternative approach for selecting new candidates is needed; such line of work should be focused on how to increase an immune response induced against the highly conserved (i.e., common to all strains), functionally relevant, protein regions that the parasite uses to invade target cells. Despite binding regions tending to be conserved, they are usually poorly antigenic and/or immunogenic, being frequently discarded as vaccine candidates when the conventional immunological approach is followed. The Fundación Instituto de Inmunología de Colombia (FIDIC) has developed a logical and rational methodology based on including conserved high-activity binding peptides (cHABPs) from the main P. falciparum biologically functional proteins involved in red blood cell (RBC) invasion. Once appropriately modified (mHABPs), these minimal, subunit-based, chemically synthesized peptides can be used in a system covering the human immune system's main genetic variables (the human leukocyte antigen HLA-DR isotype) inducing a suitable, immunogenic, and protective immune response in most of the world's populations.
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Affiliation(s)
- David Ricardo Salamanca
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Marcela Gómez
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Anny Camargo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Laura Cuy-Chaparro
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Jessica Molina-Franky
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - César Reyes
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Elkin Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Department of Pathology, School of Medicine, Universidad Nacional de Colombia, Boyacá, Colombia
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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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Akter M, Drinkwater N, Devine SM, Drew SC, Krishnarjuna B, Debono CO, Wang G, Scanlon MJ, Scammells PJ, McGowan S, MacRaild CA, Norton RS. Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe. ChemMedChem 2019; 14:603-612. [PMID: 30653832 DOI: 10.1002/cmdc.201800802] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Indexed: 11/08/2022]
Abstract
Apical membrane antigen 1 (AMA1) is essential for the invasion of host cells by malaria parasites. Several small-molecule ligands have been shown to bind to a conserved hydrophobic cleft in Plasmodium falciparum AMA1. However, a lack of detailed structural information on the binding pose of these molecules has hindered their further optimisation as inhibitors. We have developed a spin-labelled peptide based on RON2, the native binding partner of AMA1, to probe the binding sites of compounds on PfAMA1. The crystal structure of this peptide bound to PfAMA1 shows that it binds at one end of the hydrophobic groove, leaving much of the binding site unoccupied and allowing fragment hits to bind without interference. In paramagnetic relaxation enhancement (PRE)-based NMR screening, the 1 H relaxation rates of compounds binding close to the probe were enhanced. Compounds experienced different degrees of PRE as a result of their different orientations relative to the spin label while bound to AMA1. Thus, PRE-derived distance constraints can be used to identify binding sites and guide further hit optimisation.
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Affiliation(s)
- Mansura Akter
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Nyssa Drinkwater
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia
| | - Shane M Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Simon C Drew
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Bankala Krishnarjuna
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Cael O Debono
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Geqing Wang
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Martin J Scanlon
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia
| | - Christopher A MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
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11
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Reverse immunodynamics: a new method for identifying targets of protective immunity. Sci Rep 2019; 9:2164. [PMID: 30770839 PMCID: PMC6377634 DOI: 10.1038/s41598-018-37288-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 11/20/2018] [Indexed: 12/21/2022] Open
Abstract
Despite a dramatic increase in our ability to catalogue variation among pathogen genomes, we have made far fewer advances in using this information to identify targets of protective immunity. Epidemiological models predict that strong immune selection can cause antigenic variants to structure into genetically discordant sets of antigenic types (e.g. serotypes). A corollary of this theory is that targets of immunity may be identified by searching for non-overlapping associations of amino acids among co-circulating antigenic variants. We propose a novel population genetics methodology that combines such predictions with phylogenetic analyses to identify genetic loci (epitopes) under strong immune selection. We apply this concept to the AMA-1 protein of the malaria parasite Plasmodium falciparum and find evidence of epitopes among certain regions of low variability which could render them ideal vaccine candidates. The proposed method can be applied to a myriad of multi-strain pathogens for which vast amounts of genetic data has been collected in recent years.
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12
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Sun Z, Liu Q, Qu G, Feng Y, Reetz MT. Utility of B-Factors in Protein Science: Interpreting Rigidity, Flexibility, and Internal Motion and Engineering Thermostability. Chem Rev 2019; 119:1626-1665. [PMID: 30698416 DOI: 10.1021/acs.chemrev.8b00290] [Citation(s) in RCA: 280] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Qian Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ge Qu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Manfred T. Reetz
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
- Chemistry Department, Philipps-University, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
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13
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Spiegel H, Boes A, Fendel R, Reimann A, Schillberg S, Fischer R. Immunization with the Malaria Diversity-Covering Blood-Stage Vaccine Candidate Plasmodium falciparum Apical Membrane Antigen 1 DiCo in Complex with Its Natural Ligand PfRon2 Does Not Improve the In Vitro Efficacy. Front Immunol 2017; 8:743. [PMID: 28702028 PMCID: PMC5484772 DOI: 10.3389/fimmu.2017.00743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/12/2017] [Indexed: 01/05/2023] Open
Abstract
The blood-stage malaria vaccine candidate Plasmodium falciparum apical membrane antigen 1 (PfAMA1) can induce strong parasite growth-inhibitory antibody responses in animals but has not achieved the anticipated efficacy in clinical trials. Possible explanations in humans are the insufficient potency of the elicited antibody responses, as well as the high degree of sequence polymorphisms found in the field. Several strategies have been developed to improve the cross-strain coverage of PfAMA1-based vaccines, whereas innovative concepts to increase the potency of PfAMA1-specific IgG responses have received little attention even though this may be an essential requirement for protective efficacy. A previous study has demonstrated that immunization with a complex of PyAMA1 and PyRON2, a ligand with an essential functional role in erythrocyte invasion, leads to protection from lethal Plasmodium yoelli challenge in an animal model and suggested to extend this strategy toward improved strain coverage by using multiple PfAMA1 alleles in combination with PfRon2L. As an alternative approach along this line, we decided to use PfRon2L in combination with three PfAMA1 diversity covering variants (DiCo) to investigate the potential of this complex to induce more potent parasite growth inhibitory immune response in combination with better cross-strain-specific efficacy. Within the limits of the study design, the ability of the PfAMA1 DiCo-Mix to induce cross-strain-specific antibodies was not affected in all immunization groups, but the DiCo-PfRon2L complexes did not improve the potency of PfAMA1-specific IgG responses.
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Affiliation(s)
- Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Alexander Boes
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Rolf Fendel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Andreas Reimann
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany.,Institute for Phytopathology and Applied Zoology, Justus-Liebig University Giessen, Giessen, Germany
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany.,RWTH Aachen University, Institute for Molecular Biotechnology, Aachen, Germany.,Indiana Biosciences Research Institute (IBRI), Indianapolis, IN, United States
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14
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Devine SM, MacRaild CA, Norton RS, Scammells PJ. Antimalarial drug discovery targeting apical membrane antigen 1. MEDCHEMCOMM 2017; 8:13-20. [PMID: 30108688 PMCID: PMC6072474 DOI: 10.1039/c6md00495d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/27/2016] [Indexed: 01/06/2023]
Abstract
Malaria continues to frustrate humanity's attempts to eradicate this deadly disease. Although gains have been made over the last 15 years, drug resistance to malaria continues to be a major concern. The lack of new antimalarials with novel mechanisms of action continues to challenge the scientific community to find innovative targets to combat this persistent disease. One such target, apical membrane antigen 1 (AMA1), is an essential protein that helps the parasite invade host erythrocytes. Recently, a number of efforts have focused on the druggability of this target, aiming to block the interactions of AMA1 that mediate invasion of host cells. This review covers recent progress in drug discovery targeting this crucial protein-protein interaction in malaria.
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Affiliation(s)
- Shane M Devine
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Christopher A MacRaild
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Raymond S Norton
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Peter J Scammells
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
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15
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Wang G, Drinkwater N, Drew DR, MacRaild CA, Chalmers DK, Mohanty B, Lim SS, Anders RF, Beeson JG, Thompson PE, McGowan S, Simpson JS, Norton RS, Scanlon MJ. Structure–Activity Studies of β-Hairpin Peptide Inhibitors of the Plasmodium falciparum AMA1–RON2 Interaction. J Mol Biol 2016; 428:3986-3998. [DOI: 10.1016/j.jmb.2016.07.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/25/2016] [Accepted: 07/04/2016] [Indexed: 12/01/2022]
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16
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Norton RS, Leung EWW, Chandrashekaran IR, MacRaild CA. Applications of (19)F-NMR in Fragment-Based Drug Discovery. Molecules 2016; 21:molecules21070860. [PMID: 27438818 PMCID: PMC6273323 DOI: 10.3390/molecules21070860] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/21/2016] [Accepted: 06/21/2016] [Indexed: 11/16/2022] Open
Abstract
(19)F-NMR has proved to be a valuable tool in fragment-based drug discovery. Its applications include screening libraries of fluorinated fragments, assessing competition among elaborated fragments and identifying the binding poses of promising hits. By observing fluorine in both the ligand and the target protein, useful information can be obtained on not only the binding pose but also the dynamics of ligand-protein interactions. These applications of (19)F-NMR will be illustrated in this review with studies from our fragment-based drug discovery campaigns against protein targets in parasitic and infectious diseases.
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Affiliation(s)
- Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Eleanor W W Leung
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Indu R Chandrashekaran
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Christopher A MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
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17
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Krishnarjuna B, Lim SS, Devine SM, Debono CO, Lam R, Chandrashekaran IR, Jaipuria G, Yagi H, Atreya HS, Scanlon MJ, MacRaild CA, Scammells PJ, Norton RS. Solution NMR characterization of apical membrane antigen 1 and small molecule interactions as a basis for designing new antimalarials. J Mol Recognit 2016; 29:281-91. [DOI: 10.1002/jmr.2529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/28/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Bankala Krishnarjuna
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - San Sui Lim
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Shane M. Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Cael O. Debono
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Raymond Lam
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Indu R. Chandrashekaran
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Garima Jaipuria
- NMR Research Centre; Indian Institute of Science; Bangalore 560012 India
| | - Hiromasa Yagi
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | | | - Martin J. Scanlon
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Christopher A. MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Peter J. Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
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18
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Delgadillo RF, Parker ML, Lebrun M, Boulanger MJ, Douguet D. Stability of the Plasmodium falciparum AMA1-RON2 Complex Is Governed by the Domain II (DII) Loop. PLoS One 2016; 11:e0144764. [PMID: 26731670 PMCID: PMC4701444 DOI: 10.1371/journal.pone.0144764] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/22/2015] [Indexed: 12/20/2022] Open
Abstract
Plasmodium falciparum is an obligate intracellular protozoan parasite that employs a highly sophisticated mechanism to access the protective environment of the host cells. Key to this mechanism is the formation of an electron dense ring at the parasite-host cell interface called the Moving Junction (MJ) through which the parasite invades. The MJ incorporates two key parasite components: the surface protein Apical Membrane Antigen 1 (AMA1) and its receptor, the Rhoptry Neck Protein (RON) complex, the latter one being targeted to the host cell membrane during invasion. Crystal structures of AMA1 have shown that a partially mobile loop, termed the DII loop, forms part of a deep groove in domain I and overlaps with the RON2 binding site. To investigate the mechanism by which the DII loop influences RON2 binding, we measured the kinetics of association and dissociation and binding equilibria of a PfRON2sp1 peptide with both PfAMA1 and an engineered form of PfAMA1 where the flexible region of the DII loop was replaced by a short Gly-Ser linker (ΔDII-PfAMA1). The reactions were tracked by fluorescence anisotropy as a function of temperature and concentration and globally fitted to acquire the rate constants and corresponding thermodynamic profiles. Our results indicate that both PfAMA1 constructs bound to the PfRON2sp1 peptide with the formation of one intermediate in a sequential reversible reaction: A↔B↔C. Consistent with Isothermal Titration Calorimetry measurements, final complex formation was enthalpically driven and slightly entropically unfavorable. Importantly, our experimental data shows that the DII loop lengthened the complex half-life time by 18-fold (900 s and 48 s at 25°C for Pf and ΔDII-Pf complex, respectively). The longer half-life of the Pf complex appeared to be driven by a slower dissociation process. These data highlight a new influential role for the DII loop in kinetically locking the functional binary complex to enable host cell invasion.
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Affiliation(s)
- Roberto F. Delgadillo
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, CNRS, UMR 7275, 660, route des Lucioles, Sophia Antipolis, 06560, Valbonne, France
| | - Michelle L. Parker
- Department of Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
| | - Maryse Lebrun
- UMR 5235 CNRS, Université de Montpellier, 34095, Montpellier, France
| | - Martin J. Boulanger
- Department of Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
| | - Dominique Douguet
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, CNRS, UMR 7275, 660, route des Lucioles, Sophia Antipolis, 06560, Valbonne, France
- * E-mail:
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19
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Atkinson SC, Armistead JS, Mathias DK, Sandeu MM, Tao D, Borhani-Dizaji N, Tarimo BB, Morlais I, Dinglasan RR, Borg NA. The Anopheles-midgut APN1 structure reveals a new malaria transmission-blocking vaccine epitope. Nat Struct Mol Biol 2015; 22:532-9. [PMID: 26075520 PMCID: PMC4547048 DOI: 10.1038/nsmb.3048] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 05/18/2015] [Indexed: 12/31/2022]
Abstract
Mosquito-based malaria transmission-blocking vaccines (mTBVs) target midgut-surface antigens of the Plasmodium parasite's obligate vector, the Anopheles mosquito. The alanyl aminopeptidase N (AnAPN1) is the leading mTBV immunogen; however, AnAPN1's role in Plasmodium infection of the mosquito and how anti-AnAPN1 antibodies functionally block parasite transmission have remained elusive. Here we present the 2.65-Å crystal structure of AnAPN1 and the immunoreactivity and transmission-blocking profiles of three monoclonal antibodies (mAbs) to AnAPN1, including mAb 4H5B7, which effectively blocks transmission of natural strains of Plasmodium falciparum. Using the AnAPN1 structure, we map the conformation-dependent 4H5B7 neoepitope to a previously uncharacterized region on domain 1 and further demonstrate that nonhuman-primate neoepitope-specific IgG also blocks parasite transmission. We discuss the prospect of a new biological function of AnAPN1 as a receptor for Plasmodium in the mosquito midgut and the implications for redesigning the AnAPN1 mTBV.
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Affiliation(s)
- Sarah C Atkinson
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Jennifer S Armistead
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Derrick K Mathias
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Maurice M Sandeu
- Laboratoire de Recherche sur le Paludisme, Institut de Recherche pour le Développement-Organisation de Coordination et de Coopération pour la Lutte Contre les Grandes Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Dingyin Tao
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Nahid Borhani-Dizaji
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Brian B Tarimo
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [3] Nelson Mandela African Institute for Science and Technology, Arusha, Tanzania. [4] Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Isabelle Morlais
- Laboratoire de Recherche sur le Paludisme, Institut de Recherche pour le Développement-Organisation de Coordination et de Coopération pour la Lutte Contre les Grandes Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Rhoel R Dinglasan
- 1] W. Harry Feinstone Department of Molecular Microbiology &Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. [2] Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Natalie A Borg
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Parker ML, Boulanger MJ. An Extended Surface Loop on Toxoplasma gondii Apical Membrane Antigen 1 (AMA1) Governs Ligand Binding Selectivity. PLoS One 2015; 10:e0126206. [PMID: 25955165 PMCID: PMC4425356 DOI: 10.1371/journal.pone.0126206] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 03/31/2015] [Indexed: 11/18/2022] Open
Abstract
Apicomplexan parasites are the causative agents of globally prevalent diseases including malaria and toxoplasmosis. These obligate intracellular pathogens have evolved a sophisticated host cell invasion strategy that relies on a parasite-host cell junction anchored by interactions between apical membrane antigens (AMAs) on the parasite surface and rhoptry neck 2 (RON2) proteins discharged from the parasite and embedded in the host cell membrane. Key to formation of the AMA1-RON2 complex is displacement of an extended surface loop on AMA1 called the DII loop. While conformational flexibility of the DII loop is required to expose the mature RON2 binding groove, a definitive role of this substructure has not been elucidated. To establish a role of the DII loop in Toxoplasma gondii AMA1, we engineered a form of the protein where the mobile portion of the loop was replaced with a short Gly-Ser linker (TgAMA1ΔDIIloop). Isothermal titration calorimetry measurements with a panel of RON2 peptides revealed an influential role for the DII loop in governing selectivity. Most notably, an Eimeria tenella RON2 (EtRON2) peptide that showed only weak binding to TgAMA1 bound with high affinity to TgAMA1ΔDIIloop. To define the molecular basis for the differential binding, we determined the crystal structure of TgAMA1ΔDIIloop in complex with the EtRON2 peptide. When analyzed in the context of existing AMA1-RON2 structures, spatially distinct anchor points in the AMA1 groove were identified that, when engaged, appear to provide the necessary traction to outcompete the DII loop. Collectively, these data support a model where the AMA1 DII loop serves as a structural gatekeeper to selectively filter out ligands otherwise capable of binding with high affinity in the AMA1 apical groove. These data also highlight the importance of considering the functional implications of the DII loop in the ongoing development of therapeutic intervention strategies targeting the AMA1-RON2 invasion complex.
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Affiliation(s)
- Michelle L. Parker
- Department of Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
| | - Martin J. Boulanger
- Department of Biochemistry & Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada
- * E-mail:
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Pihan E, Delgadillo RF, Tonkin ML, Pugnière M, Lebrun M, Boulanger MJ, Douguet D. Computational and biophysical approaches to protein-protein interaction inhibition of Plasmodium falciparum AMA1/RON2 complex. J Comput Aided Mol Des 2015; 29:525-39. [PMID: 25822046 DOI: 10.1007/s10822-015-9842-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/25/2015] [Indexed: 11/30/2022]
Abstract
Invasion of the red blood cell by Plasmodium falciparum parasites requires formation of an electron dense circumferential ring called the Moving Junction (MJ). The MJ is anchored by a high affinity complex of two parasite proteins: Apical Membrane Antigen 1 (PfAMA1) displayed on the surface of the parasite and Rhoptry Neck Protein 2 that is discharged from the parasite and imbedded in the membrane of the host cell. Structural studies of PfAMA1 revealed a conserved hydrophobic groove localized to the apical surface that coordinates RON2 and invasion inhibitory peptides. In the present work, we employed computational and biophysical methods to identify competitive P. falciparum AMA1-RON2 inhibitors with the goal of exploring the 'druggability' of this attractive antimalarial target. A virtual screen followed by molecular docking with the PfAMA1 crystal structure was performed using an eight million compound collection that included commercial molecules, the ChEMBL malaria library and approved drugs. The consensus approach resulted in the selection of inhibitor candidates. We also developed a fluorescence anisotropy assay using a modified inhibitory peptide to experimentally validate the ability of the selected compounds to inhibit the AMA1-RON2 interaction. Among those, we identified one compound that displayed significant inhibition. This study offers interesting clues to improve the throughput and reliability of screening for new drug leads.
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Affiliation(s)
- Emilie Pihan
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, CNRS, UMR 7275, 660, Route des Lucioles, Sophia Antipolis, 06560, Valbonne, France
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