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Amoah LE, Abagna HB, Akyea-Mensah K, Lo AC, Kusi KA, Gyan BA. Characterization of anti-EBA175RIII-V in asymptomatic adults and children living in communities in the Greater Accra Region of Ghana with varying malaria transmission intensities. BMC Immunol 2018; 19:34. [PMID: 30453898 PMCID: PMC6245760 DOI: 10.1186/s12865-018-0271-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 11/08/2018] [Indexed: 11/10/2022] Open
Abstract
Background Antibodies against Region III-V of the erythrocyte binding antigen (EBA) 175 (EBA175RIII-V) have been suggested to provide protection from malaria in a natural infection. However, the quality and quantity of naturally induced antibodies to EBA175RIII-V has not been fully characterized in different cohorts of Ghanaians. This study sought to determine the characteristics of antibodies against EBA175RIII-V in asymptomatic adults and children living in two communities of varying P. falciparum parasite prevalence in southern Ghana. Methods Microscopic evaluation of thick and thin blood smears was used to identify asymptomatic Plasmodium falciparum carriage and indirect enzyme linked immunosorbent (ELISA) used to assess antibody concentrations and avidity. Results Parasite carriage estimated by microscopy in Obom was 35.6% as opposed to 3.5% in Asutsuare. Levels of IgG, IgG1, IgG2, IgG3 and IgG4 against EBA175RIII-V in the participants from Obom were significantly higher (P < 0.05, Dunn’s Multiple Comparison test) than those in Asutsuare. However the relative avidity of IgG antibodies against EBA175RIII-V was significantly higher (P < 0.0001, Mann Whitney test) in Asutsuare than in Obom. Conclusions People living in communities with limited exposure to P. falciparum parasites have low quantities of high avidity antibodies against EBA175RIII-V whilst people living in communities with high exposure to the parasites have high quantities of age-dependent but low avidity antibodies against EBA175RIII-V. Electronic supplementary material The online version of this article (10.1186/s12865-018-0271-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- L E Amoah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
| | - H B Abagna
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - K Akyea-Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - A C Lo
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.,Present address: University Cheikh Anta DIOP, Dakar, Senegal
| | - K A Kusi
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - B A Gyan
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
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2
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Abagna HB, Acquah FK, Okonu R, Aryee NA, Theisen M, Amoah LE. Assessment of the quality and quantity of naturally induced antibody responses to EBA175RIII-V in Ghanaian children living in two communities with varying malaria transmission patterns. Malar J 2018; 17:14. [PMID: 29310662 PMCID: PMC5759240 DOI: 10.1186/s12936-017-2167-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/29/2017] [Indexed: 01/26/2023] Open
Abstract
Background Recent global reports on malaria suggest significant decrease in disease severity and an increase in control interventions in many malaria endemic countries, including Ghana. However, a major driving force sustaining malaria transmission in recent times is the asymptomatic carriage of malaria parasites, which can enhance immune responses against parasite antigens. This study determined the prevalence and relative avidities of naturally induced antibodies to EBA175RIII–VLl in asymptomatic children living in two communities with varying malaria transmission patterns. Methods An asexual stage Plasmodium falciparum antigen, EBA175RIII–VLl was expressed in Lactococcus lactis, purified and used in indirect ELISA to measure total and cytophilic IgG concentrations and avidities in children aged between 6 and 12 years. The children were selected from Obom and Abura, communities with perennial and seasonal malaria transmission, respectively. Venous blood samples were collected in July and October 2015 and again in January 2016. The multiplicity of infection and the genetic diversity of EBA175RIII circulating in both sites were also assessed using polymerase chain reaction. Results Asymptomatic parasite carriage in the children from Obom decreased from July (peak season), through October and January, however parasite carriage in children from Abura was bimodal, with the lowest prevalence estimated in October. Antibody concentrations over the course of the study remained stable within each study site however, children living in Obom had significantly higher EBA175RIII–VLl antibody concentrations than children living in Abura (P < 0.05, Mann–Whitney test). Over the course of the study, the relative antibody avidities of EBA175RIII–VLl IgG antibodies were similar within and between the sites. Conclusion Naturally acquired IgG concentrations but not relative antibody avidities to EBA175RIII–V were significantly higher in Obom where malaria transmission is perennial than in Abura, where malaria transmission is seasonal. Electronic supplementary material The online version of this article (10.1186/s12936-017-2167-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hamza B Abagna
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.,Department of Medical Biochemistry, University of Ghana, Accra, Ghana
| | - Festus K Acquah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Ruth Okonu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Nii A Aryee
- Department of Medical Biochemistry, University of Ghana, Accra, Ghana
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Linda E Amoah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
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Pegha-Moukandja I, Imboumy-Limoukou RK, Tchitoula-Makaya N, Mouinga-Ondeme AG, Biteghe-Bi-Essone JC, Mba DN, Lekana-Douki JB, Ndouo FST. High Level of Specific Anti- Plasmodium Falciparum Merozoite IgG1 Antibodies in Rural Asymptomatic Individuals of Dienga, South-Eastern Gabon. Eur J Microbiol Immunol (Bp) 2017; 7:247-260. [PMID: 29403652 PMCID: PMC5793693 DOI: 10.1556/1886.2017.00010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/12/2017] [Indexed: 01/01/2023] Open
Abstract
Plasmodium falciparum merozoite antigens (PfMAgs) play an essential role in the development of immunity to malaria. Currently, P. falciparum: protein 113 (Pf 113), apical membrane antigen 1 (AMA1), erythrocyte binding antigens (EBA175), and reticulocyte binding protein homologue 5 (RH5) are among the most PfMAgs studied. A comparative analysis of naturally acquired antibodies against these antigens in children would increase our knowledge about the development of protective immunity. Analysis of antibodies to Pf113, PfAMA1, PfEBA175, and PfRH5 was conducted in rural population during 2013 and 2014. Both prevalence and levels of total IgG anti-PfAMA1 were higher than that of IgG anti-PfEBA175, anti-PfRH5, and anti-Pf113. Seroconversion to PfAMA1 and PfEBA175 occurred moderately in young children and reached to the maximum in adolescent and in adults. High prevalence of IgG anti-Pf113 was observed in young children of 3 to 6 years old in 2013. The four antigens were recognized by IgG 1, 2, 3, and 4 antibodies from a large proportion of the subjects, and all of them induced high levels of specific IgG1 against PfAMA1, PfEBA175, fewer by Pf113 and PfRH5. Many asymptomatic children had specific IgG1 recognizing multiple antigens, and these IgG1 antibodies could be associated with a reduced risk of developing malaria symptoms.
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Affiliation(s)
- Irène Pegha-Moukandja
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa.,Département de Parasitologie-Mycologie et Médecine Tropicale, Faculté de Médecine, Université des Sciences de la Santé, BP 4009, Libreville, Gabon, Africa.,Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876, Franceville, Gabon, Africa
| | - Roméo-Karl Imboumy-Limoukou
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa.,Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876, Franceville, Gabon, Africa
| | - Nina Tchitoula-Makaya
- Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876, Franceville, Gabon, Africa
| | | | - Jean Claude Biteghe-Bi-Essone
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa.,Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876, Franceville, Gabon, Africa
| | - Dieudonne Nkoghe Mba
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa
| | - Jean-Bernard Lekana-Douki
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa.,Département de Parasitologie-Mycologie et Médecine Tropicale, Faculté de Médecine, Université des Sciences de la Santé, BP 4009, Libreville, Gabon, Africa.,Ecole Doctorale Régionale en Infectiologie Tropicale d'Afrique Centrale (ECODRAC), BP 876, Franceville, Gabon, Africa
| | - Fousseyni S Toure Ndouo
- Centre International de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville Gabon, Africa
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Pratt-Riccio LR, De Souza Perce-Da-Silva D, Da Costa Lima-Junior J, Pratt Riccio EK, Ribeiro-Alves M, Santos F, Arruda M, Camus D, Druilhe P, Oliveira-Ferreira J, Daniel-Ribeiro CT, Banic DM. Synthetic Antigens Derived from Plasmodium falciparum Sporozoite, Liver, and Blood Stages: Naturally Acquired Immune Response and Human Leukocyte Antigen Associations in Individuals Living in a Brazilian Endemic Area. Am J Trop Med Hyg 2017; 97:1581-1592. [PMID: 29016339 DOI: 10.4269/ajtmh.17-0359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Peptide vaccine strategies using Plasmodium-derived antigens have emerged as an attractive approach against malaria. However, relatively few studies have been conducted with malaria-exposed populations from non-African countries. Herein, the seroepidemiological profile against Plasmodium falciparum of naturally exposed individuals from a Brazilian malaria-endemic area against synthetic peptides derived from vaccine candidates circumsporozoite protein (CSP), liver stage antigen-1 (LSA-1), erythrocyte binding antigen-175 (EBA-175), and merozoite surface protein-3 (MSP-3) was investigated. Moreover, human leukocyte antigen (HLA)-DRB1* and HLA-DQB1* were evaluated to characterize genetic modulation of humoral responsiveness to these antigens. The study was performed using blood samples from 187 individuals living in rural malaria-endemic villages situated near Porto Velho, Rondônia State. Specific IgG and IgM antibodies and IgG subclasses were detected by enzyme-linked immunosorbent assay, and HLA-DRB1* and HLA-DQB1* low-resolution typing was performed by PCR-SSP. All four synthetic peptides were broadly recognized by naturally acquired antibodies. Regarding the IgG subclass profile, only CSP induced IgG1 and IgG3 antibodies, which is an important fact given that the acquisition of protective immunity appears to be associated with the cytophilicity of IgG1 and IgG3 antibodies. HLA-DRB1*11 and HLA-DQB1*7 had the lowest odds of responding to EBA-175. Our results showed that CSP, LSA-1, EBA, and MSP-3 are immunogenic in natural conditions of exposure and that anti-EBA antibody responses appear to be modulated by HLA class II antigens.
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Affiliation(s)
| | | | | | | | - Marcelo Ribeiro-Alves
- Laboratório de Pesquisa Clínica em DST/AIDS, Instituto Nacional de Infectologia Evandro Chagas, Fiocruz, Rio de Janeiro, Brazil
| | - Fátima Santos
- Laboratório Central de Saúde Pública (LACEN), Rondônia, Brazil
| | - Mercia Arruda
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães, Fiocruz, Recife, Brazil
| | - Daniel Camus
- Service de Parasitologie-Mycologie, Faculte de Médecine, Lille, France
| | | | | | | | - Dalma Maria Banic
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
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5
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Kusi KA, Manu EA, Manful Gwira T, Kyei-Baafour E, Dickson EK, Amponsah JA, Remarque EJ, Faber BW, Kocken CHM, Dodoo D, Gyan BA, Awandare GA, Atuguba F, Oduro AR, Koram KA. Variations in the quality of malaria-specific antibodies with transmission intensity in a seasonal malaria transmission area of Northern Ghana. PLoS One 2017; 12:e0185303. [PMID: 28945794 PMCID: PMC5612719 DOI: 10.1371/journal.pone.0185303] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 09/11/2017] [Indexed: 02/07/2023] Open
Abstract
Introduction Plasmodium falciparum induced antibodies are key components of anti-malarial immunity in malaria endemic areas, but their antigen targets can be polymorphic. Induction of a high proportion of strain-specific antibodies will limit the recognition of a broad diversity of parasite strains by these responses. There are indications that circulating parasite diversity varies with malaria transmission intensity, and this may affect the specificity of elicited anti-malarial antibodies. This study therefore assessed the effect of varying malaria transmission patterns on the specificity of elicited antibody responses and to identify possible antibody correlates of naturally acquired immunity to malaria in children in an area of Ghana with seasonal malaria transmission. Methods This retrospective study utilized plasma samples collected longitudinally at six time points from children aged one to five years. Multiplex assays were used to measure antibody levels against four P. falciparum AMA 1 variants (from the 3D7, FVO, HB3 and CAMP parasite strains) and the 3D7 variant of the EBA 175 region II antigen and the levels compared between symptomatic and asymptomatic children. The relative proportions of cross-reactive and strain-specific antibodies against the four AMA 1 variants per sampling time point were assessed by Bland-Altman plots. The levels of antibodies against allelic AMA1 variants, measured by singleplex and multiplex luminex assays, were also compared. Results The data show that increased transmission intensity is associated with higher levels of cross-reactive antibody responses, most likely a result of a greater proportion of multiple parasite clone infections during the high transmission period. Anti-AMA1 antibodies were however associated with a history of infection rather than protection in this age group. Conclusion The data contribute to understanding the underlying mechanism of the acquisition of strain-transcending antibody immunity following repeated exposure to diverse parasite strains.
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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
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- * E-mail:
| | - Emmanuel A. Manu
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Theresa Manful Gwira
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied 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
| | - Emmanuel K. Dickson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Jones A. Amponsah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Edmond J. Remarque
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Bart W. Faber
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Clemens H. M. Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Daniel Dodoo
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Ben A. Gyan
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Gordon A. Awandare
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Frank Atuguba
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Abraham R. Oduro
- Navrongo Health Research Centre, Ghana Health Service, Navrongo, Ghana
| | - Kwadwo A. Koram
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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6
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Ahmed Ismail H, Tijani MK, Langer C, Reiling L, White MT, Beeson JG, Wahlgren M, Nwuba R, Persson KEM. Subclass responses and their half-lives for antibodies against EBA175 and PfRh2 in naturally acquired immunity against Plasmodium falciparum malaria. Malar J 2014; 13:425. [PMID: 25373511 PMCID: PMC4232678 DOI: 10.1186/1475-2875-13-425] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 10/25/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Plasmodium falciparum EBA175 and PfRh2 belong to two main families involved in parasite invasion, and both are potential vaccine candidates. Current knowledge is limited regarding which target antigens and subclasses of antibodies are actually important for protection, and how naturally acquired immunity is achieved. METHODS Repeated blood samples were collected from individuals in Nigeria over a period of almost one year. ELISA was used to analyse subclasses of IgG responses. RESULTS For both EBA175 (region III-V) and (a fragment of) PfRh2, the dominant antibody responses consisted of IgG1 and IgG3 followed by IgG2, while for PfRh2 there was also a relatively prominent response for IgG4. High levels of IgG1, IgG2 and IgG3 for EBA175 and total IgG for PfRh2 correlated significantly with a lower parasitaemia during the study period. Children with HbAS had higher levels of some subclasses compared to children with HbAA, while in adults the pattern was the opposite. The half-lives of IgG2 and IgG4 against EBA175 were clearly shorter than those for IgG1 and IgG3. CONCLUSION EBA175 and PfRh2 are potential targets for protective antibodies since both correlated with lower parasitaemia. The shorter half-lives for IgG2 and IgG4 might explain why these subclasses are often considered less important in protection against malaria. Triggering the right subclass responses could be of critical importance in a successful vaccine. Further studies are needed to evaluate the role of haemoglobin polymorphisms and their malaria protective effects in this process.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kristina E M Persson
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Nobels väg 16, 17177 Stockholm, Sweden.
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Sennang N, Rogerson S, Wahyuni S, Yusuf I, Syafruddin D. Antibody response against three Plasmodium falciparum merozoite antigens in Mamuju District, West Sulawesi Province, Indonesia. Malar J 2014; 13:381. [PMID: 25255775 PMCID: PMC4193137 DOI: 10.1186/1475-2875-13-381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 09/18/2014] [Indexed: 11/18/2022] Open
Abstract
Background Malaria endemicity in the archipelago of Indonesia varies substantially across regions. Following the government’s plan for a malaria elimination programme in Indonesia, baseline malaria surveys were conducted in Mamuju District, West Sulawesi Province, Indonesia to re-assess the malaria situation prior to the establishment of an evidence-based malaria elimination programme in the area. The present study aims to determine the antibody response to three merozoite antigens among the inhabitants of the district. Methods Antibodies were measured following elution from filter-paper blood spots collected during cross-sectional surveys in the dry and wet season in 2010. Enzyme-linked immunosorbent assays using three merozoite antigens, MSP2, EBA175 and PfRh2a were conducted. A positivity threshold was determined by samples from unexposed individuals and the difference in antibody level against each antigen and correlation of antibody level in different age groups and seasons were statistically analysed. Results A total of 497 subjects, 248 in dry and 249 in wet season, aged between 0.6 and 78 years were included. The prevalence of positive antibody responses to MSP2, EBA175 and PfRh2a antigens in dry season were 27.82, 27.42 and 25.81%, respectively. In wet season, the antibody prevalences were 64.26, 64.66 and 61.45%. The antibody levels to the three antigens were all higher in older age groups and also significantly higher in the wet season. The antibody levels also correlated positively with the Plasmodium falciparum infection status of the subjects. Conclusion MSP2, EBA175 and PfRh2a induce antibody responses among the subjects in Mamuju District, and the prevalence is significantly higher in wet season. The level of antibody also correlates significantly with age and malaria positivity. The overall results indicate the antigens might be used as a target for vaccines against P. falciparum infection and as markers for malaria exposure.
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Affiliation(s)
| | | | | | | | - Din Syafruddin
- Department of Parasitology, Faculty of Medicine, Hasanuddin University, Makassar 90245, South Sulawesi, Indonesia.
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Age-dependent IgG subclass responses to Plasmodium falciparum EBA-175 are differentially associated with incidence of malaria in Mozambican children. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 19:157-66. [PMID: 22169088 DOI: 10.1128/cvi.05523-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Plasmodium falciparum blood-stage antigens such as merozoite surface protein 1 (MSP-1), apical membrane antigen 1 (AMA-1), and the 175-kDa erythrocyte binding antigen (EBA-175) are considered important targets of naturally acquired immunity to malaria. However, it is not clear whether antibodies to these antigens are effectors in protection against clinical disease or mere markers of exposure. In the context of a randomized, placebo-controlled trial of intermittent preventive treatment in infants conducted between 2002 and 2004, antibody responses to Plasmodium falciparum blood-stage antigens in a cohort of 302 Mozambican children were evaluated by immunofluorescence antibody test and enzyme-linked immunosorbent assay at 5, 9, 12, and 24 months of age. We found that IgG subclass responses to EBA-175 were differentially associated with the incidence of malaria in the follow-up period. A double amount of cytophilic IgG1 or IgG3 was associated with a significant decrease in the incidence of malaria (incidence rate ratio [IRR] = 0.49, 95% confidence interval [CI] = 0.25 to 0.97, and P = 0.026 and IRR = 0.44, CI = 0.19 to 0.98, and P = 0.037, respectively), while a double amount of noncytophilic IgG4 was significantly correlated with an increased incidence of malaria (IRR = 3.07, CI = 1.08 to 8.78, P = 0.020). No significant associations between antibodies to the 19-kDa fragment of MSP-1 (MSP-1(19)) or AMA-1 and incidence of malaria were found. Age, previous episodes of malaria, present infection, and neighborhood of residence were the main factors influencing levels of antibodies to all merozoite antigens. Deeper understanding of the acquisition of antibodies against vaccine target antigens in early infancy is crucial for the rational development and deployment of malaria control tools in this vulnerable population.
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9
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Perce-da-Silva DS, Banic DM, Lima-Junior JC, Santos F, Daniel-Ribeiro CT, de Oliveira-Ferreira J, Pratt-Riccio LR. Evaluation of allelic forms of the erythrocyte binding antigen 175 (EBA-175) in Plasmodium falciparum field isolates from Brazilian endemic area. Malar J 2011; 10:146. [PMID: 21615944 PMCID: PMC3138422 DOI: 10.1186/1475-2875-10-146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 05/26/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Plasmodium falciparum Erythrocyte Binding Antigen-175 (EBA-175) is an antigen considered to be one of the leading malaria vaccine candidates. EBA-175 mediates sialic acid-dependent binding to glycophorin A on the erythrocytes playing a crucial role during invasion of the P. falciparum in the host cell. Dimorphic allele segments, termed C-fragment and F-fragment, have been found in high endemicity malaria areas and associations between the dimorphism and severe malaria have been described. In this study, the genetic dimorphism of EBA-175 was evaluated in P. falciparum field isolates from Brazilian malaria endemic area. METHODS The study was carried out in rural villages situated near Porto Velho, Rondonia State in the Brazilian Amazon in three time points between 1993 and 2008. The allelic dimorphism of the EBA-175 was analysed by Nested PCR. RESULTS The classical allelic dimorphism of the EBA-175 was identified in the studied area. Overall, C-fragment was amplified in a higher frequency than F-fragment. The same was observed in the three time points where C-fragment was observed in a higher frequency than F-fragment. Single infections (one fragment amplified) were more frequent than mixed infection (two fragments amplified). CONCLUSIONS These findings confirm the dimorphism of EBA175, since only the two types of fragments were amplified, C-fragment and F-fragment. Also, the results show the remarkable predominance of CAMP allele in the studied area. The comparative analysis in three time points indicates that the allelic dimorphism of the EBA-175 is stable over time.
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Affiliation(s)
- Daiana S Perce-da-Silva
- Laboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, Fiocruz, Manguinhos, Rio de Janeiro, RJ - CEP: 21040-900 Brazil
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10
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Duah NO, Miles DJC, Whittle HC, Conway DJ. Acquisition of antibody isotypes against Plasmodium falciparum blood stage antigens in a birth cohort. Parasite Immunol 2010; 32:125-34. [PMID: 20070826 PMCID: PMC2814092 DOI: 10.1111/j.1365-3024.2009.01165.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/20/2009] [Indexed: 11/28/2022]
Abstract
Information on the period during which infants lose their maternally derived antibodies to malaria and begin to acquire naturally their own immune responses against parasite antigens is crucial for understanding when malaria vaccines may be best administered. This study investigated the rates of decline and acquisition of serum antibody isotypes IgG1, IgG2, IgG3, IgG4, IgM and IgA to Plasmodium falciparum antigens apical membrane antigen (AMA1), merozoite surface proteins (MSP1-19, MSP2 and MSP3) in a birth cohort of 53 children living in an urban area in the Gambia, followed over the first 3 years of life (sampled at birth, 4, 9, 18 and 36 months). Antigen-specific maternally transferred antibody isotypes of all IgG subclasses were detected at birth and were almost totally depleted by 4 months of age. Acquisition of specific antibody isotypes to the antigens began with IgM, followed by IgG1 and IgA. Against the MSP2 antigen, IgG1 but not IgG3 responses were observed in the children, in contrast with the maternally derived antibodies to this antigen that were mostly IgG3. This confirms that IgG subclass responses to MSP2 are strongly dependent on age or previous malaria experience, polarized towards IgG1 early in life and to IgG3 in older exposed individuals.
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Affiliation(s)
- N O Duah
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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Breadth and magnitude of antibody responses to multiple Plasmodium falciparum merozoite antigens are associated with protection from clinical malaria. Infect Immun 2008; 76:2240-8. [PMID: 18316390 DOI: 10.1128/iai.01585-07] [Citation(s) in RCA: 300] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Individuals living in areas where malaria is endemic are repeatedly exposed to many different malaria parasite antigens. Studies on naturally acquired antibody-mediated immunity to clinical malaria have largely focused on the presence of responses to individual antigens and their associations with decreased morbidity. We hypothesized that the breadth (number of important targets to which antibodies were made) and magnitude (antibody level measured in a random serum sample) of the antibody response were important predictors of protection from clinical malaria. We analyzed naturally acquired antibodies to five leading Plasmodium falciparum merozoite-stage vaccine candidate antigens, and schizont extract, in Kenyan children monitored for uncomplicated malaria for 6 months (n = 119). Serum antibody levels to apical membrane antigen 1 (AMA1) and merozoite surface protein antigens (MSP-1 block 2, MSP-2, and MSP-3) were inversely related to the probability of developing malaria, but levels to MSP-1(19) and erythrocyte binding antigen (EBA-175) were not. The risk of malaria was also inversely associated with increasing breadth of antibody specificities, with none of the children who simultaneously had high antibody levels to five or more antigens experiencing a clinical episode (17/119; 15%; P = 0.0006). Particular combinations of antibodies (AMA1, MSP-2, and MSP-3) were more strongly predictive of protection than others. The results were validated in a larger, separate case-control study whose end point was malaria severe enough to warrant hospital admission (n = 387). These findings suggest that under natural exposure, immunity to malaria may result from high titers antibodies to multiple antigenic targets and support the idea of testing combination blood-stage vaccines optimized to induce similar antibody profiles.
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Enevold A, Nkya WMMM, Theisen M, Vestergaard LS, Jensen AT, Staalsoe T, Theander TG, Bygbjerg IC, Alifrangis M. Potential impact of host immunity on malaria treatment outcome in Tanzanian children infected with Plasmodium falciparum. Malar J 2007; 6:153. [PMID: 18021388 PMCID: PMC2206045 DOI: 10.1186/1475-2875-6-153] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 11/16/2007] [Indexed: 11/25/2022] Open
Abstract
Background In malaria endemic areas children may recover from malaria after chemotherapy in spite of harbouring genotypically drug-resistant Plasmodium falciparum. This phenomenon suggests that there is a synergy between drug treatment and acquired immunity. This hypothesis was examined in an area of moderately intense transmission of P. falciparum in Tanzania during a drug trail with sulphadoxine-pyrimethamine (SP) or amodiaquine (AQ). Methods One hundred children with uncomplicated malaria were treated with either SP or AQ and followed for 28 days. Mutations in parasite genes related to SP and AQ-resistance as well as human sickle cell trait and alpha-thalassaemia were determined using PCR and sequence-specific oligonucleotide probes and enzyme-linked immunosorbent assay (SSOP-ELISA), and IgG antibody responses to a panel of P. falciparum antigens were assessed and related to treatment outcome. Results Parasitological or clinical treatment failure (TF) was observed in 68% and 38% of children receiving SP or AQ, respectively. In those with adequate clinical and parasitological response (ACPR) compared to children with TF, and for both treatment regimens, prevalence and levels of anti-Glutamate-rich Protein (GLURP)-specific IgG antibodies were significantly higher (P < 0.001), while prevalence of parasite haplotypes associated with SP and AQ resistance was lower (P = 0.02 and P = 0.07, respectively). Interestingly, anti-GLURP-IgG antibodies were more strongly associated with treatment outcome than parasite resistant haplotypes, while the IgG responses to none of the other 11 malaria antigens were not significantly associated with ACPR. Conclusion These findings suggest that GLURP-specific IgG antibodies in this setting contribute to clearance of drug-resistant infections and support the hypothesis that acquired immunity enhances the clinical efficacy of drug therapy. The results should be confirmed in larger scale with greater sample size and with variation in transmission intensity.
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Affiliation(s)
- Anders Enevold
- Centre for Medical Parasitology, Institute of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
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