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B-Cell Epitope Mapping of the Plasmodium falciparum Malaria Vaccine Candidate GMZ2.6c in a Naturally Exposed Population of the Brazilian Amazon. Vaccines (Basel) 2023; 11:vaccines11020446. [PMID: 36851323 PMCID: PMC9966924 DOI: 10.3390/vaccines11020446] [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: 01/09/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
The GMZ2.6c malaria vaccine candidate is a multi-stage P. falciparum chimeric protein that contains a fragment of the sexual-stage Pfs48/45-6C protein genetically fused to GMZ2, an asexual-stage vaccine construction consisting of the N-terminal region of the glutamate-rich protein (GLURP) and the C-terminal region of the merozoite surface protein-3 (MSP-3). Previous studies showed that GMZ2.6c is widely recognized by antibodies from Brazilian exposed individuals and that its components are immunogenic in natural infection by P. falciparum. In addition, anti-GMZ2.6c antibodies increase with exposure to infection and may contribute to parasite immunity. Therefore, identifying epitopes of proteins recognized by antibodies may be an important tool for understanding protective immunity. Herein, we identify and validate the B-cell epitopes of GMZ2.6c as immunogenic and immunodominant in individuals exposed to malaria living in endemic areas of the Brazilian Amazon. Specific IgG antibodies and subclasses against MSP-3, GLURP, and Pfs48/45 epitopes were detected by ELISA using synthetic peptides corresponding to B-cell epitopes previously described for MSP-3 and GLURP or identified by BepiPred for Pfs48/45. The results showed that the immunodominant epitopes were P11 from GLURP and MSP-3c and DG210 from MSP-3. The IgG1 and IgG3 subclasses were preferentially induced against these epitopes, supporting previous studies that these proteins are targets for cytophilic antibodies, important for the acquisition of protective immunity. Most individuals presented detectable IgG antibodies against Pfs48/45a and/or Pfs48/45b, validating the prediction of linear B-cell epitopes. The higher frequency and antibody levels against different epitopes from GLURP, MSP-3, and Pfs48/45 provide additional information that may suggest the relevance of GMZ2.6c as a multi-stage malaria vaccine candidate.
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Opi DH, Kurtovic L, Chan JA, Horton JL, Feng G, Beeson JG. Multi-functional antibody profiling for malaria vaccine development and evaluation. Expert Rev Vaccines 2021; 20:1257-1272. [PMID: 34530671 DOI: 10.1080/14760584.2021.1981864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for Plasmodium falciparum, a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials. AREAS COVERED In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite. We highlight the growing understanding of antibody effector functions against malaria and in vitro assays to measure these functional antibody responses. We discuss the application of these assays to quantify antibody functions in vaccine development and evaluation. EXPERT OPINION It is becoming increasingly clear that multiple antibody effector functions are involved in immunity to malaria. Therefore, we propose that evaluating vaccine candidates needs to move beyond individual assays or measuring IgG magnitude alone. Instead, vaccine evaluation should incorporate the full breadth of antibody response types and harness a wider range of assays measuring functional antibody responses. We propose a 3-tier approach to implementing assays to inform vaccine evaluation.
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Affiliation(s)
- D Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jessica L Horton
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia
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Dassah S, Adu B, Sirima SB, Mordmüller B, Ngoa UA, Atuguba F, Arthur FKN, Mensah BA, Kaddumukasa M, Bang P, Kremsner PG, Mategula D, Flach C, Milligan P, Theisen M. Extended follow-up of children in a phase2b trial of the GMZ2 malaria vaccine. Vaccine 2021; 39:4314-4319. [PMID: 34175127 DOI: 10.1016/j.vaccine.2021.06.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND The GMZ2/alum candidate malaria vaccine had an efficacy of 14% (95% confidence interval [CI]: 3.6%, 23%) against clinical malaria over 6 months of follow-up in a phase2b multicentre trial in children 1-5 years of age. Here we report the extended follow up of safety and efficacy over 2 years. METHODS A total of 1849 (GMZ2 = 926, rabies = 923) children aged 12-60 months were randomized to receive intramuscularly, either 3 doses of 100 μg GMZ2/alum or 3 doses of rabies vaccine as control 28 days apart. The children were followed-up for 24 months for clinical malaria episodes and adverse events. The primary endpoint was documented fever with parasitaemia of at least 5000/μL. RESULTS There were 2,062 malaria episodes in the GMZ2/alum group and 2,115 in the rabies vaccine group in the intention-to-treat analysis, vaccine efficacy (VE) of 6.5% (95%: CI -1.6%, 14.0%). In children aged 1-2 years at enrolment, VE was 3.6% (95 %CI: -9.1%, 14.8%) in the first year and -4.1% (95 %CI: -18.7%, 87%) in the second year. In children aged 3-5 years at enrolment VE was 19.9% (95 %CI: 7.7%, 30.4%) in the first year and 6.3% (95 %CI: -10.2%, 20.3%) in the second year (interaction by year, P = 0.025, and by age group, P = 0.085). A total of 187 (GMZ2 = 91, rabies = 96) serious adverse events were recorded in 167 individuals over the entire period of the study. There were no GMZ2 vaccine related serious adverse events. CONCLUSIONS GMZ2/alum was well tolerated. Follow-up over 2 years confirmed a low level of vaccine efficacy with slightly higher efficacy in older children, which suggests GMZ2 may act in concert with naturally acquired immunity.
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Affiliation(s)
- Sylvester Dassah
- Navrongo Health Research Centre, Navrongo, Ghana; Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Bright Adu
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Sodiomon B Sirima
- National de Recherche et de Formation sur le Paludisme, Burkina Faso
| | | | - Ulysse Ateba Ngoa
- Institute of Tropical Medicine, University of Tübingen, Germany; Centre de Recherches Médicales de Lambaréné (CERMEL), Gabon
| | | | - Fareed K N Arthur
- Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Benedicta A Mensah
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | | | - Peter Bang
- Department for Vaccine Development, Statens Serum Institut, Copenhagen, Denmark
| | - Peter G Kremsner
- National de Recherche et de Formation sur le Paludisme, Burkina Faso; Institute of Tropical Medicine, University of Tübingen, Germany
| | - Donnie Mategula
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, UK
| | - Clare Flach
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, UK
| | - Paul Milligan
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, UK
| | - 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, and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark.
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Hamre KES, Ondigo BN, Hodges JS, Dutta S, Theisen M, Ayodo G, John CC. Antibody Correlates of Protection from Clinical Plasmodium falciparum Malaria in an Area of Low and Unstable Malaria Transmission. Am J Trop Med Hyg 2020; 103:2174-2182. [PMID: 33124533 DOI: 10.4269/ajtmh.18-0805] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Immune correlates of protection against clinical malaria are difficult to ascertain in low-transmission areas because of the limited number of malaria cases. We collected blood samples from 5,753 individuals in a Kenyan highland area, ascertained malaria incidence in this population over the next 6 years, and then compared antibody responses to 11 Plasmodium falciparum vaccine candidate antigens in individuals who did versus did not develop clinical malaria in a nested case-control study (154 cases and 462 controls). Individuals were matched by age and village. Antigens tested included circumsporozoite protein (CSP), liver-stage antigen (LSA)-1, apical membrane antigen-1 FVO and 3D7 strains, erythrocyte-binding antigen-175, erythrocyte-binding protein-2, merozoite surface protein (MSP)-1 FVO and 3D7 strains, MSP-3, and glutamate-rich protein (GLURP) N-terminal non-repetitive (R0) and C-terminal repetitive (R2) regions. After adjustment for potential confounding factors, the presence of antibodies to LSA-1, GLURP-R2, or GLURP-R0 was associated with decreased odds of developing clinical malaria (odds ratio [OR], [95% CI] 0.56 [0.36-0.89], 0.56 [0.36-0.87], and 0.77 [0.43-1.02], respectively). Levels of antibodies to LSA-1, GLURP-R2, and CSP were associated with decreased odds of developing clinical malaria (OR [95% CI]; 0.61 [0.41-0.89], 0.60 [0.43-0.84], and 0.49 [0.24-0.99], for every 10-fold increase in antibody levels, respectively). The presence of antibodies to CSP, GLURP-R0, GLURP-R2, and LSA-1 combined best-predicted protection from clinical malaria. Antibodies to CSP, GLURP-R0, GLURP-R2, and LSA-1 are associated with protection against clinical malaria in a low-transmission setting. Vaccines containing these antigens should be evaluated in low malaria transmission areas.
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Affiliation(s)
- Karen E S Hamre
- CDC Foundation, Atlanta, Georgia.,Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota.,Division of Global Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Bartholomew N Ondigo
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.,Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.,Department of Biochemistry and Molecular Biology, Egerton University, Nakuru, Kenya
| | - James S Hodges
- Division of Biostatistics, University of Minnesota, Minneapolis, Minnesota
| | - Sheetij Dutta
- Walter Reed Army Institute for Research, Silver Spring, Maryland
| | | | - George Ayodo
- Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya.,Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Chandy C John
- Division of Global Pediatrics, University of Minnesota, Minneapolis, Minnesota.,Department of Biochemistry and Molecular Biology, Egerton University, Nakuru, Kenya.,Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota.,Department of Pediatrics, Indiana University, Indianapolis, Indiana
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Nguetse CN, Ojo JA, Nchotebah C, Ikegbunam MN, Meyer CG, Thomas BN, Velavan TP, Ojurongbe O. Genetic Diversity of the Plasmodium falciparum Glutamate-Rich Protein R2 Region Before and Twelve Years after Introduction of Artemisinin Combination Therapies among Febrile Children in Nigeria. Am J Trop Med Hyg 2018; 98:667-676. [PMID: 29363449 PMCID: PMC5930894 DOI: 10.4269/ajtmh.17-0621] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/14/2017] [Indexed: 11/07/2022] Open
Abstract
The genetic diversity of glutamate-rich protein (GLURP) R2 region in Plasmodium falciparum isolates collected before and 12 years after the introduction of artemisinin combination treatment of malaria in Osogbo, Osun State, Nigeria, was compared in this study. Blood samples were collected on filter paper in 2004 and 2015 from febrile children from ages 1-12 years. The R2 region of the GLURP gene was genotyped using nested polymerase chain reaction and by nucleotide sequencing. In all, 12 GLURP alleles were observed in a total of 199 samples collected in the two study years. The multiplicity of infection (MOI) marginally increased over the two study years; however, the differences were statistically insignificant (2004 samples MOI = 1.23 versus 2015 samples MOI = 1.47). Some alleles were stable in their prevalence, whereas two GLURP alleles, VIII and XI, showed considerable variability between both years. This variability was replicated when GLURP sequences from other regions were compared with ours. The expected heterozygosity (He) values (He = 0.87) were identical for the two groups. High variability in the rearrangement of the amino acid repeat units in the R2 region were observed, with the amino acid repeat sequence DKNEKGQHEIVEVEEILPE more prevalent in both years, compared with the two other repeat sequences observed in the study. The parasite population characterized in this study displayed extensive genetic diversity. The detailed genetic profile of the GLURP R2 region has the potential to help guide further epidemiological studies aimed toward the rational design of novel chemotherapies that are antagonistic toward malaria.
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Affiliation(s)
- Christian N. Nguetse
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Johnson Adeyemi Ojo
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria
| | - Charles Nchotebah
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Moses Nkechukwu Ikegbunam
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikwe University, Akwa, Nigeria
| | - Christian G. Meyer
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Duy Tan University, Da Nang, Vietnam
| | - Bolaji N. Thomas
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, New York
| | - Thirumalaisamy P. Velavan
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Duy Tan University, Da Nang, Vietnam
- Fondation Congolaise pour la Recherche Médicale, Brazzaville, Republic of Congo
| | - Olusola Ojurongbe
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria
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Patel P, Bharti PK, Bansal D, Raman RK, Mohapatra PK, Sehgal R, Mahanta J, Sultan AA, Singh N. Genetic diversity and antibody responses against Plasmodium falciparum vaccine candidate genes from Chhattisgarh, Central India: Implication for vaccine development. PLoS One 2017; 12:e0182674. [PMID: 28787005 PMCID: PMC5546615 DOI: 10.1371/journal.pone.0182674] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/21/2017] [Indexed: 11/22/2022] Open
Abstract
The genetic diversity in Plasmodium falciparum antigens is a major hurdle in developing an effective malaria vaccine. Protective efficacy of the vaccine is dependent on the polymorphic alleles of the vaccine candidate antigens. Therefore, we investigated the genetic diversity of the potential vaccine candidate antigens i.e. msp-1, msp-2, glurp, csp and pfs25 from field isolates of P.falciparum and determined the natural immune response against the synthetic peptide of these antigens. Genotyping was performed using Sanger method and size of alleles, multiplicity of infection, heterogeneity and recombination rate were analyzed. Asexual stage antigens were highly polymorphic with 55 and 50 unique alleles in msp-1 and msp-2 genes, respectively. The MOI for msp-1 and msp-2 were 1.67 and 1.28 respectively. A total 59 genotype was found in glurp gene with 8 types of amino acid repeats in the conserved part of RII repeat region. The number of NANP repeats from 40 to 44 was found among 55% samples in csp gene while pfs25 was found almost conserved with only two amino acid substitution site. The level of genetic diversity in the present study population was very similar to that from Asian countries. A higher IgG response was found in the B-cell epitopes of msp-1 and csp antigens and higher level of antibodies against csp B-cell epitope and glurp antigen were recorded with increasing age groups. Significantly, higher positive responses were observed in the csp antigen among the samples with ≥42 NANP repeats. The present finding showed extensive diversity in the asexual stage antigens.
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Affiliation(s)
- Priyanka Patel
- National Institute for Research in Tribal Health, Indian Council of Medical Research, Garha, Jabalpur, Madhya Pradesh, India
| | - Praveen K. Bharti
- National Institute for Research in Tribal Health, Indian Council of Medical Research, Garha, Jabalpur, Madhya Pradesh, India
| | - Devendra Bansal
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Qatar Foundation - Education City, Doha, Qatar
| | - Rajive K. Raman
- Community Health Centre Janakpur, District Baikunthpur, Chhattisgarh, India
| | - Pradyumna K. Mohapatra
- Regional Medical Research Centre, NE, Indian Council of Medical Research, Dibrugarh, Assam, India
| | - Rakesh Sehgal
- Department of Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, Punjab, India
| | - Jagadish Mahanta
- Regional Medical Research Centre, NE, Indian Council of Medical Research, Dibrugarh, Assam, India
| | - Ali A. Sultan
- Department of Microbiology and Immunology, Weill Cornell Medicine - Qatar, Cornell University, Qatar Foundation - Education City, Doha, Qatar
| | - Neeru Singh
- National Institute for Research in Tribal Health, Indian Council of Medical Research, Garha, Jabalpur, Madhya Pradesh, India
- * E-mail:
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Theisen M, Adu B, Mordmüller B, Singh S. The GMZ2 malaria vaccine: from concept to efficacy in humans. Expert Rev Vaccines 2017; 16:907-917. [PMID: 28699823 DOI: 10.1080/14760584.2017.1355246] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION GMZ2 is a recombinant protein consisting of conserved domains of GLURP and MSP3, two asexual blood-stage antigens of Plasmodium falciparum, and is designed with the aim of mimicking naturally acquired anti-malarial immunity. The rationale for combining these two antigens is based on a series of immune epidemiological studies from geographically diverse malaria endemic regions; functional in vitro studies; and pre-clinical studies in rodents and New World monkeys. GMZ2 adjuvanted with alhydrogel® (alum) was well tolerated and immunogenic in three phase 1 studies. The recently concluded phase 2 trial of GMZ2/alum, involving 1849 participants 12 to 60 month of age in four countries in West, Central and Eastern Africa, showed that GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects for clinical development of GMZ2 sub-unit vaccine. We will focus on discovery, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production, pre-clinical and clinical studies. Expert commentary: GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. More immunogenic formulations should be developed.
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Affiliation(s)
- Michael Theisen
- a Department for Congenital Disorders , Statens Serum Institut , Copenhagen , Denmark.,b Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology , University of Copenhagen , Copenhagen , Denmark.,c Department of Infectious Diseases , Copenhagen University Hospital , Rigshospitalet , Denmark
| | - Bright Adu
- d Noguchi Memorial Institute for Medical Research , University of Ghana , Legon , Ghana
| | - Benjamin Mordmüller
- e Institute of Tropical Medicine and Center for Infection Research, partner site Tübingen , University of Tübingen , Tübingen , Germany
| | - Subhash Singh
- f Indian Institute of Integrative Medicine , Jammu , India
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Sero-epidemiological evaluation of Plasmodium falciparum malaria in Senegal. Malar J 2015; 14:275. [PMID: 26173958 PMCID: PMC4502940 DOI: 10.1186/s12936-015-0789-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 07/01/2015] [Indexed: 11/13/2022] Open
Abstract
Background In Senegal, a significant decrease of malaria transmission intensity has been noted the last years. Parasitaemia has become lower and, therefore, more difficult to detect by microscopy. In the context of submicroscopic parasitaemia, it has become relevant to rely on relevant malaria surveillance tools to better document malaria epidemiology in such settings. Serological markers have been proposed as an essential tool for malaria surveillance. This study aimed to evaluate the sero-epidemiological situation of Plasmodium falciparum malaria in two sentinel sites in Senegal. Methods Cross-sectional surveys were carried out in Velingara (south Senegal) and Keur Soce (central Senegal) between September and October 2010. Children under 10 years old, living in these areas, were enrolled using two-level, random sampling methods. P. falciparum infection was diagnosed using microscopy. P. falciparum antibodies against circumsporozoite protein (CSP), apical membrane protein (AMA1) and merozoite surface protein 1_42 (MSP1_42) were measured by ELISA method. A stepwise logistic regression analysis was done to assess factors associated with P. falciparum antibodies carriage. Results A total of 1,865 children under 10 years old were enrolled. The overall falciparum malaria prevalence was 4.99% with high prevalence in Velingara of 10.03% compared to Keur Soce of 0.3%. Symptomatic malaria cases (fever associated with parasitaemia) represented 17.37%. Seroprevalence of anti-AMA1, anti-MSP1_42 and anti-CSP antibody was 38.12, 41.55 and 40.38%, respectively. The seroprevalence was more important in Velingara and increased with age, active malaria infection and area of residence. Conclusion The use of serological markers can contribute to improved malaria surveillance in areas with declining malaria transmission. This study provided useful baseline information about the sero-epidemiological situation of malaria in Senegal and can contribute to the identification of malaria hot spots in order to concentrate intervention efforts. Trial registration number: PACTR201305000551876 (http://www.pactr.org).
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Balam S, Olugbile S, Servis C, Diakité M, D'Alessandro A, Frank G, Moret R, Nebie I, Tanner M, Felger I, Smith T, Kajava AV, Spertini F, Corradin G. Plasmodium falciparum merozoite surface protein 2: epitope mapping and fine specificity of human antibody response against non-polymorphic domains. Malar J 2014; 13:510. [PMID: 25526742 PMCID: PMC4320585 DOI: 10.1186/1475-2875-13-510] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/06/2014] [Indexed: 11/16/2022] Open
Abstract
Background Two long synthetic peptides representing the dimorphic and constant C-terminal domains of the two allelic families of Plasmodium falciparum merozoite surface proteins 2 are considered promising malaria vaccine candidates. The aim of the current study is to characterize the immune response (epitope mapping) in naturally exposed individuals and relate immune responses to the risk of clinical malaria. Methods To optimize their construction, the fine specificity of human serum antibodies from donors of different age, sex and living in four distinct endemic regions was determined in ELISA by using overlapping 20 mer peptides covering the two domains. Immune purified antibodies were used in Western blot and immunofluorescence assay to recognize native parasite derivate proteins. Results Immunodominant epitopes were characterized, and their distribution was similar irrespective of geographic origin, age group and gender. Acquisition of a 3D7 family and constant region-specific immune response and antibody avidity maturation occur early in life while a longer period is needed for the corresponding FC27 family response. In addition, the antibody response to individual epitopes within the 3D7 family-specific region contributes to protection from malaria infection with different statistical weight. It is also illustrated that affinity-purified antibodies against the dimorphic or constant regions recognized homologous and heterologous parasites in immunofluorescence and homologous and heterologous MSP2 and other polypeptides in Western blot. Conclusion Data from this current study may contribute to a development of MSP2 vaccine candidates based on conserved and dimorphic regions thus bypassing the complexity of vaccine development related to the polymorphism of full-length MSP2. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-510) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Saidou Balam
- Department of Biochemistry, University of Lausanne, Ch des Boveresses 155, 1066 Epalinges, Switzerland.
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10
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Duru KC, Thomas BN. Genetic Diversity and Allelic Frequency of Glutamate-Rich Protein (GLURP) in Plasmodium falciparum Isolates from Sub-Saharan Africa. Microbiol Insights 2014; 7:35-9. [PMID: 25452699 PMCID: PMC4240185 DOI: 10.4137/mbi.s20618] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/21/2014] [Accepted: 10/24/2014] [Indexed: 11/05/2022] Open
Abstract
Glutamate-rich protein is a Plasmodium falciparum (Pf) antigen found in all stages of the parasite and has been reported to induce clinical immunity. The R0 and R2 regions have been found to exhibit a high degree of conservation, therefore serving as a good vaccine design material. We assayed the genetic diversity of Pf glurp genes in the R0 and R2 regions, as well as evaluated the role of seasonality on allelic frequency. A total of 402 genomic DNA samples, extracted from filter paper blood samples, were screened by nested polymerase chain reaction (PCR) analysis of Pf glurp R0 and R2 regions, in addition to fragment analysis of the polymorphic regions to identify allelic diversity of the parasite population. We found an extensive heterogeneity in the R2 region in general, and this heterogeneity is seasonally dependent, indicative of region plasticity. The R0 region displayed genetic conservation, as expected. We conclude that positive genotyping results with glurp R0 region should be seen as indicative of an active Pf infection, requiring adequate treatment. In addition, we advocate extending the possibility that an R0 region genotypic positivity could serve as diagnostic tool, thereby reducing cases of untreated or poorly treated infection, contributory to recrudescence or treatment failure.
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Affiliation(s)
- Kimberley C Duru
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Bolaji N Thomas
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA
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Gomes LR, Totino PRR, Sanchez MCA, Daniel EPDSK, Macedo CSD, Fortes F, Coura JR, Santi SMD, Werneck GL, Suárez-Mutis MC, Ferreira-da-Cruz MDF, Daniel-Ribeiro CT. Asymptomatic infection in individuals from the municipality of Barcelos (Brazilian Amazon) is not associated with the anti-Plasmodium falciparum glycosylphosphatidylinositol antibody response. Mem Inst Oswaldo Cruz 2014; 108:796-800. [PMID: 24037204 PMCID: PMC3970686 DOI: 10.1590/0074-0276108062013018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 05/16/2013] [Indexed: 11/21/2022] Open
Abstract
Anti-glycosylphosphatidylinositol (GPI) antibodies (Abs) may reflect and mediate,
at least partially, anti-disease immunity in malaria by neutralising the toxic
effect of parasitic GPI. Thus, we assessed the anti-GPI Ab response in
asymptomatic individuals living in an area of the Brazilian Amazon that has a
high level of malaria transmission. For comparative purposes, we also
investigated the Ab response to a crude extract prepared from Plasmodium
falciparum, the merozoite surface protein (MSP)3 antigen of
P. falciparum and the MSP 1 antigen of Plasmodium
vivax (PvMSP1-19) in these individuals and in Angolan
patients with acute malaria. Our data suggest that the Ab response against
P. falciparum GPI is not associated with P.
falciparum asymptomatic infection in individuals who have been
chronically exposed to malaria in the Brazilian Amazon. However, this Ab
response could be related to ongoing parasitaemia (as was previously shown) in
the Angolan patients. In addition, our data show that PvMSP1-19may be
a good marker antigen to reflect previous exposure to
Plasmodium in areas that have a high transmission rate of
P. vivax.
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12
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Theisen M, Roeffen W, Singh SK, Andersen G, Amoah L, van de Vegte-Bolmer M, Arens T, Tiendrebeogo RW, Jones S, Bousema T, Adu B, Dziegiel MH, Christiansen M, Sauerwein R. A multi-stage malaria vaccine candidate targeting both transmission and asexual parasite life-cycle stages. Vaccine 2014; 32:2623-30. [DOI: 10.1016/j.vaccine.2014.03.020] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/28/2014] [Accepted: 03/05/2014] [Indexed: 11/27/2022]
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13
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Jepsen MPG, Jogdand PS, Singh SK, Esen M, Christiansen M, Issifou S, Hounkpatin AB, Ateba-Ngoa U, Kremsner PG, Dziegiel MH, Olesen-Larsen S, Jepsen S, Mordmüller B, Theisen M. The Malaria Vaccine Candidate GMZ2 Elicits Functional Antibodies in Individuals From Malaria Endemic and Non-Endemic Areas. J Infect Dis 2013; 208:479-88. [DOI: 10.1093/infdis/jit185] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Ondigo BN, Park GS, Gose SO, Ho BM, Ochola LA, Ayodo GO, Ofulla AV, John CC. Standardization and validation of a cytometric bead assay to assess antibodies to multiple Plasmodium falciparum recombinant antigens. Malar J 2012; 11:427. [PMID: 23259607 PMCID: PMC3546950 DOI: 10.1186/1475-2875-11-427] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 12/20/2012] [Indexed: 11/30/2022] Open
Abstract
Background Multiplex cytometric bead assay (CBA) have a number of advantages over ELISA for antibody testing, but little information is available on standardization and validation of antibody CBA to multiple Plasmodium falciparum antigens. The present study was set to determine optimal parameters for multiplex testing of antibodies to P. falciparum antigens, and to compare results of multiplex CBA to ELISA. Methods Antibodies to ten recombinant P. falciparum antigens were measured by CBA and ELISA in samples from 30 individuals from a malaria endemic area of Kenya and compared to known positive and negative control plasma samples. Optimal antigen amounts, monoplex vs multiplex testing, plasma dilution, optimal buffer, number of beads required were assessed for CBA testing, and results from CBA vs. ELISA testing were compared. Results Optimal amounts for CBA antibody testing differed according to antigen. Results for monoplex CBA testing correlated strongly with multiplex testing for all antigens (r = 0.88-0.99, P values from <0.0001 - 0.004), and antibodies to variants of the same antigen were accurately distinguished within a multiplex reaction. Plasma dilutions of 1:100 or 1:200 were optimal for all antigens for CBA testing. Plasma diluted in a buffer containing 0.05% sodium azide, 0.5% polyvinylalcohol, and 0.8% polyvinylpyrrolidone had the lowest background activity. CBA median fluorescence intensity (MFI) values with 1,000 antigen-conjugated beads/well did not differ significantly from MFI with 5,000 beads/well. CBA and ELISA results correlated well for all antigens except apical membrane antigen-1 (AMA-1). CBA testing produced a greater range of values in samples from malaria endemic areas and less background reactivity for blank samples than ELISA. Conclusion With optimization, CBA may be the preferred method of testing for antibodies to P. falciparum antigens, as CBA can test for antibodies to multiple recombinant antigens from a single plasma sample and produces a greater range of values in positive samples and lower background readings for blank samples than ELISA.
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Affiliation(s)
- Bartholomew N Ondigo
- Department of Biomedical Science and Technology, Maseno University, Maseno, Kenya.
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15
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Tamborrini M, Stoffel SA, Westerfeld N, Amacker M, Theisen M, Zurbriggen R, Pluschke G. Immunogenicity of a virosomally-formulated Plasmodium falciparum GLURP-MSP3 chimeric protein-based malaria vaccine candidate in comparison to adjuvanted formulations. Malar J 2011; 10:359. [PMID: 22166048 PMCID: PMC3265551 DOI: 10.1186/1475-2875-10-359] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 12/13/2011] [Indexed: 12/02/2022] Open
Abstract
Background In clinical trials, immunopotentiating reconstituted influenza virosomes (IRIVs) have shown great potential as a versatile antigen delivery platform for synthetic peptides derived from Plasmodium falciparum antigens. This study describes the immunogenicity of a virosomally-formulated recombinant fusion protein comprising domains of the two malaria vaccine candidate antigens MSP3 and GLURP. Methods The highly purified recombinant protein GMZ2 was coupled to phosphatidylethanolamine and the conjugates incorporated into the membrane of IRIVs. The immunogenicity of this adjuvant-free virosomal formulation was compared to GMZ2 formulated with the adjuvants Montanide ISA 720 and Alum in three mouse strains with different genetic backgrounds. Results Intramuscular injections of all three candidate vaccine formulations induced GMZ2-specific antibody responses in all mice tested. In general, the humoral immune response in outbred NMRI mice was stronger than that in inbred BALB/c and C57BL/6 mice. ELISA with the recombinant antigens demonstrated immunodominance of the GLURP component over the MSP3 component. However, compared to the Al(OH)3-adjuvanted formulation the two other formulations elicited in NMRI mice a larger proportion of anti-MSP3 antibodies. Analyses of the induced GMZ2-specific IgG subclass profiles showed for all three formulations a predominance of the IgG1 isotype. Immune sera against all three formulations exhibited cross-reactivity with in vitro cultivated blood-stage parasites. Immunofluorescence and immunoblot competition experiments showed that both components of the hybrid protein induced IgG cross-reactive with the corresponding native proteins. Conclusion A virosomal formulation of the chimeric protein GMZ2 induced P. falciparum blood stage parasite cross-reactive IgG responses specific for both MSP3 and GLURP. GMZ2 thus represents a candidate component suitable for inclusion into a multi-valent virosomal malaria vaccine and influenza virosomes represent a versatile antigen delivery system suitable for adjuvant-free immunization with recombinant proteins.
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Affiliation(s)
- Marco Tamborrini
- Swiss Tropical and Public Health Institute, Socinstr. 57, CH 4002 Basel, Switzerland
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16
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Turner L, Wang CW, Lavstsen T, Mwakalinga SB, Sauerwein RW, Hermsen CC, Theander TG. Antibodies against PfEMP1, RIFIN, MSP3 and GLURP are acquired during controlled Plasmodium falciparum malaria infections in naïve volunteers. PLoS One 2011; 6:e29025. [PMID: 22174947 PMCID: PMC3236238 DOI: 10.1371/journal.pone.0029025] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/18/2011] [Indexed: 11/19/2022] Open
Abstract
Antibodies to polymorphic antigens expressed during the parasites erythrocytic stages are important mediators of protective immunity against P. falciparum malaria. Therefore, polymorphic blood stage antigens like MSP3, EBA-175 and GLURP and variant surface antigens PfEMP1 and RIFIN are considered vaccine candidates. However, to what extent these antibodies to blood stage antigens are acquired during naive individuals' first infections has not been studied in depth. Using plasma samples collected from controlled experimental P. falciparum infections we show that antibodies against variant surface antigens, PfEMP1 and RIFIN as well as MSP3 and GLURP, are acquired during a single short low density P. falciparum infection in non-immune individuals including strain transcendent PfEMP1 immune responses. These data indicate that the immunogenicity of the variant surface antigens is similar to the less diverse merozoite antigens. The acquisition of a broad and strain transcendent repertoire of PfEMP1 antibodies may reflect a parasite strategy of expressing most or all PfEMP1 variants at liver release optimizing the likelihood of survival and establishment of chronic infections in the new host.
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Affiliation(s)
- Louise Turner
- Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Christian W. Wang
- Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- * E-mail:
| | - Thomas Lavstsen
- Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Steven B. Mwakalinga
- Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Cornelus C. Hermsen
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Thor G. Theander
- Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
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17
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Naturally acquired immune responses to Plasmodium falciparum sexual stage antigens Pfs48/45 and Pfs230 in an area of seasonal transmission. Infect Immun 2011; 79:4957-64. [PMID: 21969000 DOI: 10.1128/iai.05288-11] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acquisition of immunity to Plasmodium falciparum sexual stages is a key determinant for reducing human-mosquito transmission by preventing the fertilization and the development of the parasite in the mosquito midgut. Naturally acquired immunity against sexual stages may therefore form the basis for the development of transmission-blocking vaccines, but studies conducted to date offer little in the way of consistent findings. Here, we describe the acquisition of antigametocyte immune responses in malaria-exposed individuals in Burkina Faso. A total of 719 blood samples were collected in a series of three cross-sectional surveys at the start, peak, and end of the wet season. The seroprevalence of antibodies with specificity for the sexual stage antigens Pfs48/45 and Pfs230 was 2-fold lower (22 to 28%) than that for an asexual blood stage antigen glutamate-rich protein (GLURP) (65%) or for the preerythrocytic stage antigen circumsporozoite protein (CSP) (54%). The youngest children responded at frequencies similar to those for all four antigens but, in contrast with the immune responses to GLURP and CSP that increased with age independently of season and area of residence, there was no evidence for a clear age dependence of responses to Pfs48/45 and Pfs230. Anti-Pfs230 antibodies were most prevalent at the peak of the wet season (P < 0.001). Our findings suggest that naturally acquired immunity against Pfs48/45 and Pfs230 is a function of recent exposure rather than of cumulative exposure to gametocytes.
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18
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Pratt-Riccio LR, Bianco-Junior C, Totino PRR, Perce-Da-Silva DDS, Silva LA, Riccio EKP, Ennes-Vidal V, Neves-Ferreira AGC, Perales J, Rocha SLGD, Dias-Da-Silva F, Ferreira-da-Cruz MDF, Daniel-Ribeiro CT, Oliveira-Ferreira JD, Theisen M, Carvalho LJDM, Banic DM. Antibodies against the Plasmodium falciparum glutamate-rich protein from naturally exposed individuals living in a Brazilian malaria-endemic area can inhibit in vitro parasite growth. Mem Inst Oswaldo Cruz 2011; 106 Suppl 1:34-43. [DOI: 10.1590/s0074-02762011000900005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 06/01/2011] [Indexed: 11/22/2022] Open
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19
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Lousada-Dietrich S, Jogdand PS, Jepsen S, Pinto VV, Ditlev SB, Christiansen M, Larsen SO, Fox CB, Raman VS, Howard RF, Vedvick TS, Ireton G, Carter D, Reed SG, Theisen M. A synthetic TLR4 agonist formulated in an emulsion enhances humoral and Type 1 cellular immune responses against GMZ2 – A GLURP–MSP3 fusion protein malaria vaccine candidate. Vaccine 2011; 29:3284-92. [DOI: 10.1016/j.vaccine.2011.02.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 01/14/2011] [Accepted: 02/07/2011] [Indexed: 11/26/2022]
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Patarroyo ME, Bermúdez A, Patarroyo MA. Structural and Immunological Principles Leading to Chemically Synthesized, Multiantigenic, Multistage, Minimal Subunit-Based Vaccine Development. Chem Rev 2011; 111:3459-507. [DOI: 10.1021/cr100223m] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Manuel Elkin Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50, No. 26-00, Bogotá, Colombia
- Universidad Nacional de Colombia
| | - Adriana Bermúdez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50, No. 26-00, Bogotá, Colombia
- Universidad del Rosario
| | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50, No. 26-00, Bogotá, Colombia
- Universidad del Rosario
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Abstract
This review considers the stages of the development of synthetic peptide vaccines against infectious agents, novel approaches and technologies employed in this process, including bioinformatics, genomics, proteomics, large-scale peptide synthesis, high-throughput screening methods, the use of transgenic animals for modelling human infections. An important role for the development and selection of efficient adjuvants for peptide immunogens is noted. Examples of synthetic peptide vaccine developments against three infectious diseases (malaria, hepatitis C, and foot-and-mouth disease) are given.
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Affiliation(s)
- A.A. Moysa
- Institute of Biomedical Chemistry, Russian Academy of Medical sciences
| | - E.F. Kolesanova
- Institute of Biomedical Chemistry, Russian Academy of Medical sciences
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22
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Moisa AA, Kolesanova EF. Synthetic peptide vaccines. BIOCHEMISTRY MOSCOW-SUPPLEMENT SERIES B-BIOMEDICAL CHEMISTRY 2010. [DOI: 10.1134/s1990750810040025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Abstract
The demonstration of efficacy of two candidate malaria vaccines in children living in malaria-endemic areas, namely RTS,S from the circumsporozoite protein that reduced infection and clinical malaria in Mozambique, and an asexual blood-stage vaccine combining MSP1/MSP2/RESA that reduced parasite density in Papua New Guinea, allows one to believe that a malaria vaccine will be available for the fight against malaria in the next decade. Even if long-lasting impregnated bednets and indoor residual spraying have proven to be effective in reducing malaria transmission, these interventions may not be sufficient in the long-run since they rely on too few compounds and are, thus, vulnerable to the emergence of resistance. New tools, such as malaria vaccines, may, therefore, provide an added value to achieve the goal of local elimination and subsequent eradication of malaria. A promising candidate for that purpose would be a highly efficacious multicomponent vaccine that includes at least a sexual-stage antigen, the appropriate initial setting would be an area with low endemicity and limited population exchange, and the most suitable mode of delivery would be mass vaccination. For nonimmune populations, such as travelers visiting malaria-endemic areas, the usefulness of the first generation of malaria vaccine(s) will be limited, since the level of protection that is foreseen is unlikely to achieve that of malaria chemoprophylaxis. Only long-term travelers, expatriates and soldiers might realistically benefit from a pre-erythrocytic and/or blood-stage vaccine with an intermediate level of efficacy.
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Dodoo D, Aikins A, Kusi KA, Lamptey H, Remarque E, Milligan P, Bosomprah S, Chilengi R, Osei YD, Akanmori BD, Theisen M. Cohort study of the association of antibody levels to AMA1, MSP119, MSP3 and GLURP with protection from clinical malaria in Ghanaian children. Malar J 2008; 7:142. [PMID: 18664257 PMCID: PMC2529305 DOI: 10.1186/1475-2875-7-142] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 07/29/2008] [Indexed: 11/24/2022] Open
Abstract
Background Antigen-specific antibody-mediated immune responses play an important role in natural protection against clinical malaria, but conflicting estimates of this association have emerged from immuno-epidemiological studies in different geographical settings. This study was aimed at assessing in a standardized manner the relationship between the antibody responses to four malaria vaccine candidate antigens and protection from clinical malaria, in a cohort of Ghanaian children. Methods Standardized ELISA protocols were used to measure isotype and IgG subclass levels to Apical Membrane Antigen 1 (AMA1), Merozoite Surface Protein 1–19 (MSP119), Merozoite Surface Protein 3 (MSP3) and Glutamate Rich Protein (GLURP) antigens in plasma samples from 352 Ghanaian children, aged three to 10 years with subsequent malaria surveillance for nine months. This is one of a series of studies in different epidemiological settings using the same standardized ELISA protocols to permit comparisons of results from different laboratories. Results The incidence rate of malaria was 0.35 episodes per child per year. Isotype and IgG subclasses for all antigens investigated increased with age, while the risk of malaria decreased with age. After adjusting for age, higher levels of IgG to GLURP, MSP119, MSP3 and IgM to MSP119, MSP3 and AMA1 were associated with decreased malaria incidence. Of the IgG subclasses, only IgG1 to MSP119 was associated with reduced incidence of clinical malaria. A previous study in the same location failed to find an association of antibodies to MSP119 with clinical malaria. The disagreement may be due to differences in reagents, ELISA and analytical procedures used in the two studies. When IgG, IgM and IgG subclass levels for all four antigens were included in a combined model, only IgG1 [(0.80 (0.67–0.97), p = 0.018)] and IgM [(0.48 (0.32–0.72), p < 0.001)] to MSP119 were independently associated with protection from malaria. Conclusion Using standardized procedures, the study has confirmed the importance of antibodies to MSP119 in reducing the risk of clinical malaria in Ghanaian children, thus substantiating its potential as a malaria vaccine candidate.
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Affiliation(s)
- Daniel Dodoo
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
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25
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Abstract
PURPOSE OF REVIEW The aim of this article is to highlight the challenges that researchers face in the development of asexual blood-stage vaccines, and the progress made recently towards achieving the goal of a successful candidate to reduce morbidity. RECENT FINDINGS There is good rationale to support the development of blood-stage malaria vaccines, the most promising being the demonstration that nonimmune volunteers repeatedly challenged and cured with blood-stage parasites developed immunity to subsequent challenge as well as the demonstration of the efficacy of the first asexual blood-stage vaccine tested in a malaria endemic area (combination B) to reduce parasite density in children. The selective pressure induced by this vaccine and the accumulating evidence of extensive antigenic diversity of blood-stage proteins pose a difficult challenge to vaccine researchers. Numerous clinical trials, both in nonendemic and endemic areas, are being conducted with different antigens, different allelic types and different protein fragments. SUMMARY Considerable efforts and funding are available to shift from laboratory experiments to field trials. Field trials remain the definitive method to assess the real impact of different vaccines in the target populations. More rigorous side-by-side comparisons are needed between the different vaccines using standardized in-vitro and in-vivo testing, so that the most promising candidates will be selected for further development.
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Affiliation(s)
- Blaise Genton
- Ifakara Health Research and Development Center, Dar Es Salaam, Tanzania.
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26
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Girard MP, Reed ZH, Friede M, Kieny MP. A review of human vaccine research and development: malaria. Vaccine 2006; 25:1567-80. [PMID: 17045367 DOI: 10.1016/j.vaccine.2006.09.074] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Accepted: 09/25/2006] [Indexed: 11/18/2022]
Abstract
The last several years have seen significant progress in the development of vaccines against malaria. Most recently, proof-of-concept of vaccine-induced protection from malaria infection and disease was demonstrated in African children. Pursued by various groups and on many fronts, several other candidate vaccines are in early clinical trials. Yet, despite the optimism and promise, an effective malaria vaccine is not yet available, in part because of the lack of understanding of the types of immune responses needed for protection, added to the difficulty of identifying, selecting and producing the appropriate protective antigens from a parasite with a genome of well over five thousand genes and to the frequent need to enhance the immunogenicity of purified antigens through the use of novel adjuvants or delivery systems. Insufficient clinical trial capacity and normative research functions such as local ethical committee reviews also contribute to slow down the development process. This article attempts to summarize the state of the art of malaria vaccine development.
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Affiliation(s)
- Marc P Girard
- University Paris 7, 39 rue Seignemartin, FR-69008 Lyon, France.
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Glutamate-rich protein (GLURP) induces antibodies that inhibit in vitro growth of Plasmodium falciparum in a phase 1 malaria vaccine trial. Vaccine 2006; 25:2930-40. [PMID: 16914240 DOI: 10.1016/j.vaccine.2006.06.081] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Revised: 06/01/2006] [Accepted: 06/20/2006] [Indexed: 11/23/2022]
Abstract
The glutamate-rich protein (GLURP) of P. falciparum is the target of cytophilic antibodies which are significantly associated with protection against clinical malaria. A phase 1 clinical trial was conducted in healthy adult volunteers with the long synthetic peptide (LSP) GLURP(85-213) combined with either Aluminum Hydroxide (Alum, 18 volunteers) or Montanide ISA 720 (ISA, 18 volunteers) as adjuvants. Immunizations with 10, 30 or 100 microg GLURP(85-213) were administered subcutaneously at days 0, 30, and 120. Adverse events occurred more frequently with increasing dosage of GLURP(85-213) LSP and were more prevalent in the ISA group. Serious vaccine-related adverse events were not observed. The vaccine induced dose-dependent cellular and humoral immune responses, with high levels of (mainly cytophilic IgG1) antibodies that recognize parasites by immunofluorescence (IFA). Plasma samples collected 30 days after the last immunization induced a dose-dependent inhibition of parasite growth in vitro in the presence of monocytes. In conclusion, immunizations with GLURP(85-213) LSP formulations induce adverse events but can be administered safely, generating antibodies with capacity to mediate growth-inhibitory activity against P. falciparum in vitro.
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28
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Lundquist R, Nielsen LK, Jafarshad A, Soesoe D, Christensen LH, Druilhe P, Dziegiel MH. Human recombinant antibodies against Plasmodium falciparum merozoite surface protein 3 cloned from peripheral blood leukocytes of individuals with immunity to malaria demonstrate antiparasitic properties. Infect Immun 2006; 74:3222-31. [PMID: 16714549 PMCID: PMC1479282 DOI: 10.1128/iai.00928-05] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunoglobulins from individuals with immunity to malaria have a strong antiparasitic effect when transferred to Plasmodium falciparum malaria infected patients. One prominent target of antiparasitic antibodies is the merozoite surface antigen 3 (MSP-3). We have investigated the antibody response against MSP-3 residues 194 to 257 (MSP-3(194-257)) on the molecular level. mRNA from peripheral blood leukocytes from clinically immune individuals was used as a source of Fab (fragment antibody) genes. A Fab-phage display library was made, and three distinct antibodies designated RAM1, RAM2, and RAM3 were isolated by panning. Immunoglobulin G1 (IgG1) and IgG3 full-length antibodies have been produced in CHO cells. Reactivity with the native parasite protein was demonstrated by immunofluorescence microscopy, flow cytometry, and immunoblotting. Furthermore, the antiparasitic effect of RAM1 has been tested in vitro in an antibody-dependent cellular inhibition (ADCI) assay. Both the IgG1 and the IgG3 versions of the antibody show an inhibitory effect on parasite growth.
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Affiliation(s)
- Rasmus Lundquist
- H:S Blodbanken KI2033, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark.
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29
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Matondo Maya DW, Mavoungou E, Deloron P, Theisen M, Ntoumi F. Distribution of IgG subclass antibodies specific for Plasmodium falciparum glutamate-rich-protein molecule in sickle cell trait children with asymptomatic infections. Exp Parasitol 2005; 112:92-8. [PMID: 16356497 DOI: 10.1016/j.exppara.2005.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Revised: 09/23/2005] [Accepted: 09/24/2005] [Indexed: 11/18/2022]
Abstract
Polymorphism in the beta-globin gene (hemoglobin S) has been associated with protection against severe forms of malaria. In a cross-sectional study, 180 young Gabonese children with and without sickle cell trait and harboring asymptomatic Plasmodium falciparum infections, were assessed for the responses to recombinant protein containing the conserved region of glutamate-rich protein (GLURP). We reported increased age-dependence of antibody prevalence and levels of total IgG (p<0.0001), IgG1 (p=0.009), and IgG3 (p<0.03) antibodies to GLURP with a cut-off at 5 years of age. Whatever the hemoglobin type, cytophilic antibodies (IgG1 and IgG3) were prevalent, but GLURP-specific IgG4 antibodies were detected at significantly (p<0.05) lower levels in HbAS children. We showed that the distribution of non-cytophilic IgG antibodies differs according to the hemoglobin type and to the malaria antigens tested. This may have possible implication for the clearance of malaria parasites and for protection against severe malaria.
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Carvalho LJM, Alves FA, Bianco C, Oliveira SG, Zanini GM, Soe S, Druilhe P, Theisen M, Muniz JAPC, Daniel-Ribeiro CT. Immunization of Saimiri sciureus monkeys with a recombinant hybrid protein derived from the Plasmodium falciparum antigen glutamate-rich protein and merozoite surface protein 3 can induce partial protection with Freund and Montanide ISA720 adjuvants. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 12:242-8. [PMID: 15699417 PMCID: PMC549299 DOI: 10.1128/cdli.12.2.242-248.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immunogenicity and efficacy of a hybrid recombinant protein derived from the N-terminal end of the glutamate-rich protein (GLURP) and the C-terminal portion of the merozoite surface protein 3 (MSP3) of Plasmodium falciparum was evaluated in Saimiri sciureus monkeys. The GLURP/MSP3 hybrid protein, expressed in Lactococcus lactis, was administered in association with alum, Montanide ISA720, or complete or incomplete Freund adjuvant (CFA/IFA) in groups of five animals each. The three formulations were shown to be immunogenic, but the one with alum was shown to be weak compared to the other two, particularly CFA/IFA, which provided very high antibody titers (enzyme-linked immunosorbent assay titers of >3,000,000 and immunofluorescence antibody test titers of 6,400). After a challenge infection with P. falciparum FUP strain, all five monkeys from the GLURP/MSP3-alum group showed a rapid increase in parasitemia, reaching 10% and were treated early. The two monkeys with the highest antibody titers in group GLURP/MSP3-Montanide ISA720 had a delay in the course of parasitemia and were treated late due to a low hematocrit. In the GLURP/MSP3-CFA/IFA group, parasitemia remained below this threshold in four of the five animals and, after it reached a peak, parasitemia started to decrease and monkeys were treated late. When all animals were grouped according to the outcome, a statistically significant association between high antibody titers and partial protection was observed. The challenge infection boosted the antibody titers, and the importance of this event for vaccine efficacy in areas where this parasite is endemic is discussed. In conclusion, these data suggest that GLURP and MSP3 can induce protection against malaria infection if antibodies are induced at properly high titers.
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Affiliation(s)
- Leonardo J M Carvalho
- Laboratory of Malaria Research, Department of Immunology, Instituto Oswaldo Cruz/Fiocruz, Pavilhão Leonidas Deane, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ-Brazil 21045-900.
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31
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Caro-Aguilar I, Lapp S, Pohl J, Galinski MR, Moreno A. Chimeric epitopes delivered by polymeric synthetic linear peptides induce protective immunity to malaria. Microbes Infect 2005; 7:1324-37. [PMID: 16253535 DOI: 10.1016/j.micinf.2005.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Revised: 03/21/2005] [Accepted: 04/26/2005] [Indexed: 11/26/2022]
Abstract
Polymeric linear peptide chimeras (LPCs) that incorporate Plasmodium vivax promiscuous T cell epitopes and the P. falciparum circumsporozoite protein B cell epitope have been shown to induce a high level of immunogenicity and overcome genetic restriction when tested as vaccine immunogens in BALB/c mice. The present study evaluates the biological relevance of several LPCs using a well characterized rodent malaria model. Polymeric peptide constructs based on P. berghei and P. yoelii sequences, and orthologous to the human malaria sequences included in the original LPCs, were designed and tested for immunogenicity in mice of different H-2 haplotypes. We demonstrate that robust immune responses are induced and that peptides containing the orthologous rodent Plasmodium sequences exhibited similar immunogenic capabilities. Unique to this report, we show that LPCs can also prime MHC class I-restricted cytotoxic T lymphocytes (CTLs) and, most relevantly, that a peptide construct prototype incorporating single B, T and CTL epitopes induced protection against an experimental challenge with P. berghei or P. yoelii sporozoites. Collectively, these results suggest that polymeric polypeptide chimeras can be used as a platform to deliver subunit vaccines.
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Affiliation(s)
- Ivette Caro-Aguilar
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA
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32
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Corradin G, Spertini F, Verdini A. Medicinal application of long synthetic peptide technology. Expert Opin Biol Ther 2005; 4:1629-39. [PMID: 15461574 DOI: 10.1517/14712598.4.10.1629] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This review covers the latest developments of long synthetic peptide technology for the rapid identification and development of malaria vaccine candidates and immunological modulators. A brief description of the two most common solid-phase synthetic procedures, together with the latest advances in optimisation of peptide chain assembly and analytical instrumentation, is given, with special attention to non-specialists. Several examples of vaccine candidates developed in the authors' or their collaborators' laboratories are also provided.
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Meraldi V, Nebié I, Tiono AB, Diallo D, Sanogo E, Theisen M, Druilhe P, Corradin G, Moret R, Sirima BS. Natural antibody response to Plasmodium falciparum Exp-1, MSP-3 and GLURP long synthetic peptides and association with protection. Parasite Immunol 2004; 26:265-72. [PMID: 15541030 DOI: 10.1111/j.0141-9838.2004.00705.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A longitudinal study was undertaken in Burkina Faso among 293 children aged 6 months to 9 years in order to determine the correlation between an antibody response to several individual malarial antigens and malarial infection. It was found that the presence of a positive antibody response at the beginning of the rainy season to three long synthetic peptides corresponding to Plasmodium falciparum Exp-1 101-162, MSP-3 154-249 and GLURP 801-920 but not to CSP 274-375 correlated with a statistically significant decrease in malarial infection during the ongoing transmission season. The simultaneous presence of an antibody response to more than one antigen is indicative of a lower frequency of malarial infection. This gives scientific credibility to the notion that a successful malaria vaccine should contain multiple antigens.
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Affiliation(s)
- V Meraldi
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
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34
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Flick K, Ahuja S, Chene A, Bejarano MT, Chen Q. Optimized expression of Plasmodium falciparum erythrocyte membrane protein 1 domains in Escherichia coli. Malar J 2004; 3:50. [PMID: 15601471 PMCID: PMC544839 DOI: 10.1186/1475-2875-3-50] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 12/15/2004] [Indexed: 11/10/2022] Open
Abstract
Background The expression of recombinant proteins in Escherichia coli is an important and frequently used tool within malaria research, however, this method remains problematic. High A/T versus C/G content and frequent lysine and arginine repeats in the Plasmodium falciparum genome are thought to be the main reason for early termination in the mRNA translation process. Therefore, the majority of P. falciparum derived recombinant proteins is expressed only as truncated forms or appears as insoluble inclusion bodies within the bacterial cells. Methods Several domains of PfEMP1 genes obtained from different P. falciparum strains were expressed in E. coli as GST-fusion proteins. Expression was carried out under various culture conditions with a main focus on the time point of induction in relation to the bacterial growth stage. Results and conclusions When expressed in E. coli recombinant proteins derived from P. falciparum sequences are often truncated and tend to aggregate what in turn leads to the formation of insoluble inclusion bodies. The analysis of various factors influencing the expression revealed that the time point of induction plays a key role in successful expression of A/T rich sequences into their native conformation. Contrary to recommended procedures, initiation of expression at post-log instead of mid-log growth phase generated significantly increased amounts of soluble protein of a high quality. Furthermore, these proteins were shown to be functionally active. Other factors such as temperature, pH, bacterial proteases or the codon optimization for E. coli had little or no effect on the quality of the recombinant protein, nevertheless, optimizing these factors might be beneficial for each individual construct. In conclusion, changing the timepoint of induction and conducting expression at the post-log stage where the bacteria have entered a decelerated growth phase, greatly facilitates and improves the expression of sequences containing rare codons.
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Affiliation(s)
- Kirsten Flick
- Microbiology and Tumor Biology Centre (MTC), Karolinska Institutet, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Box 280, 171 77, Stockholm, Sweden
| | - Sanjay Ahuja
- Microbiology and Tumor Biology Centre (MTC), Karolinska Institutet, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Box 280, 171 77, Stockholm, Sweden
| | - Arnaud Chene
- Microbiology and Tumor Biology Centre (MTC), Karolinska Institutet, Stockholm, Sweden
- Center for Infectious Medicine, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Teresa Bejarano
- Microbiology and Tumor Biology Centre (MTC), Karolinska Institutet, Stockholm, Sweden
- Center for Infectious Medicine, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Qijun Chen
- Microbiology and Tumor Biology Centre (MTC), Karolinska Institutet, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Box 280, 171 77, Stockholm, Sweden
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Cavanagh DR, Dodoo D, Hviid L, Kurtzhals JAL, Theander TG, Akanmori BD, Polley S, Conway DJ, Koram K, McBride JS. Antibodies to the N-terminal block 2 of Plasmodium falciparum merozoite surface protein 1 are associated with protection against clinical malaria. Infect Immun 2004; 72:6492-502. [PMID: 15501780 PMCID: PMC522997 DOI: 10.1128/iai.72.11.6492-6502.2004] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This longitudinal prospective study shows that antibodies to the N-terminal block 2 region of the Plasmodium falciparum merozoite surface protein 1 (MSP-1) are associated with protection against clinical malaria in an area of stable but seasonal malaria transmission of Ghana. Antibodies to the block 2 region of MSP-1 were measured in a cohort of 280 children before the beginning of the major malaria transmission season. The cohort was then actively monitored for malaria, clinically and parasitologically, over a period of 17 months. Evidence is presented for an association between antibody responses to block 2 and a significantly reduced risk of subsequent clinical malaria. Furthermore, statistical survival analysis provides new information on the duration of the effect over time. The results support a conclusion that the block 2 region of MSP-1 is a target of protective immunity against P. falciparum and, thus, a promising new candidate for the development of a malaria vaccine.
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Affiliation(s)
- David R Cavanagh
- Institute of Cell, Animal and Population Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, West Mains Rd., EH9 3JT, Scotland, UK.
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36
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Theisen M, Soe S, Brunstedt K, Follmann F, Bredmose L, Israelsen H, Madsen SM, Druilhe P. A Plasmodium falciparum GLURP–MSP3 chimeric protein; expression in Lactococcus lactis, immunogenicity and induction of biologically active antibodies. Vaccine 2004; 22:1188-98. [PMID: 15003647 DOI: 10.1016/j.vaccine.2003.09.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2003] [Revised: 09/17/2003] [Accepted: 09/24/2003] [Indexed: 11/24/2022]
Abstract
Plasmodium falciparum malaria is a major cause of morbidity and mortality worldwide. To evaluate the efficacy of a possible vaccine antigen against P. falciparum infection, a fusion protein, derived from P. falciparum Glutamate-rich protein (GLURP) genetically coupled to P. falciparum Merozoite surface protein 3 (MSP3) was produced in Lactococcus lactis as a secreted recombinant GLURP-MSP3 fusion protein. The hybrid protein was purified to homogeneity by ion exchange and hydrophobic-interaction chromatography and its composition was verified by MALDI MS, SDS/PAGE and Western blotting with antibodies against antigenic components of GLURP and MSP3. Mice immunized with the hybrid protein produced higher levels of both GLURP- and MSP3-specific antibodies than mice immunized with either GLURP, MSP3 or a mix of both. The protective potential of the hybrid protein was also demonstrated by in vitro parasite-growth inhibition of mouse anti-GLURP-MSP3 IgG antibodies in a monocyte-dependent manner. These results indicate that the GLURP-MSP3 hybrid could be a valuable strategy for future P. falciparum vaccine development.
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MESH Headings
- Animals
- Antibodies, Protozoan/analysis
- Antibodies, Protozoan/biosynthesis
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Chromatography, High Pressure Liquid
- Enzyme-Linked Immunosorbent Assay
- Female
- Fermentation
- Fluorescent Antibody Technique, Indirect
- Immunoglobulin G/analysis
- Immunoglobulin G/immunology
- Lactococcus lactis/genetics
- Lactococcus lactis/metabolism
- Mice
- Mice, Inbred BALB C
- Plasmids/genetics
- Plasmodium falciparum/immunology
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Spectrometry, Mass, Electrospray Ionization
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Vaccines, Synthetic/biosynthesis
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Michael Theisen
- Department of Clinical Biochemistry, Statens Serum Institut, Copenhagen, Denmark.
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Mahanty S, Saul A, Miller LH. Progress in the development of recombinant and synthetic blood-stage malaria vaccines. J Exp Biol 2003; 206:3781-8. [PMID: 14506213 DOI: 10.1242/jeb.00646] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe use of asexual blood-stage proteins as malaria vaccines is strongly supported by experimental data directly implicating antibodies induced by these antigens in parasite clearance and protection from re-challenge. The selection of blood-stage antigens is based on their ability to interfere with the pathogenesis of clinical malaria by reducing parasitemias. These vaccines could complement other vaccines aimed at preventing infection, such as those targeted at pre-erythrocytic or mosquito stages of the parasite. Asexual blood-stage vaccines may reduce disease by blockade of red blood cell invasion, inhibition of parasite growth in red cells or interference in cytoadherence of infected red cells. Clearance of blood-stage parasites is dependent primarily on antibody-mediated mechanisms, but CD4 T cells may also play an important role in help for B cells and probably have a direct effector function in the clearance of blood-stage parasites. Since asexual blood-stage parasites reside within erythrocytes, they are accessible to immune clearance mechanisms only for a short time, which imposes special requirements on vaccines. For example, immunity that induces high titers of antibody will be required. Antigenic variation and extensive polymorphism of malarial proteins also needs to be addressed. Several recombinant antigens derived from blood-stage proteins have moved beyond basic research and are now poised for phase I trials in endemic countries. In this review we discuss the state of asexual blood-stage vaccines, focusing on recombinant antigens from Plasmodium falciparum. The significance of polymorphism and antigenic variation, the relevance of parasite immune evasion mechanisms, the need for reliable measures of successful intervention and new adjuvants are reviewed. Results from trials of asexual blood stage vaccine that support the continued effort to develop these antigens as key ingredients of multicomponent,multistage malaria vaccines are documented.
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Affiliation(s)
- Siddhartha Mahanty
- Malaria Vaccine Development Unit, NIAID, NIH, Twin Brook I, 5640 Fishers Lane, Rockville, MD 20852, USA.
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38
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Metzger WG, Okenu DMN, Cavanagh DR, Robinson JV, Bojang KA, Weiss HA, McBride JS, Greenwood BM, Conway DJ. Serum IgG3 to the Plasmodium falciparum merozoite surface protein 2 is strongly associated with a reduced prospective risk of malaria. Parasite Immunol 2003; 25:307-12. [PMID: 14507328 DOI: 10.1046/j.1365-3024.2003.00636.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The merozoite surface protein 2 (MSP2) of Plasmodium falciparum is recognized by human antibodies elicited during natural infections, and may be a target of protective immunity. In this prospective study, serum IgG antibodies to MSP2 were determined in a cohort of 329 Gambian children immediately before the annual malaria transmission season, and the incidence of clinical malaria in the following 5 months was monitored. Three recombinant MSP2 antigens were used, representing each of the two major allelic serogroups and a conserved region. The prevalence of serum IgG to each antigen correlated positively with age and with the presence of parasitaemia at the time of sampling. These antibodies were associated with a reduced subsequent incidence of clinical malaria during the follow-up. This trend was seen for both IgG1 and IgG3, although the statistical significance was greater for IgG3, the most common subclass against MSP2. After adjusting for potentially confounding effects of age and pre-season parasitaemia, IgG3 reactivities against each of the major serogroups of MSP2 remained significantly associated with a lower prospective risk of clinical malaria. Individuals who had IgG3 reactivity to both of the MSP2 serogroup antigens had an even more significantly reduced risk. Importantly, this effect remained significant after adjusting for a simultaneous strong protective association of antibodies to another antigen (MSP1 block 2) which itself remained highly significant.
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Affiliation(s)
- Wolfram G Metzger
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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