Research

Malaria Journal

, 12:326

Open Access This content is freely available online to anyone, anywhere at any time.

Cellular and humoral immune responses against the Plasmodium vivax MSP-119 malaria vaccine candidate in individuals living in an endemic area in north-eastern Amazon region of Brazil

  • Evelyn KP RiccioAffiliated withLaboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, FiocruzCentro de Pesquisa, Diagnóstico e Treinamento em Malária (CPD-Mal), Fiocruz, Reference Center for Malaria in the Extra-Amazonian Region for the Secretary for Health Surveillance from the Ministry of Health
  • , Paulo RR TotinoAffiliated withLaboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, FiocruzCentro de Pesquisa, Diagnóstico e Treinamento em Malária (CPD-Mal), Fiocruz, Reference Center for Malaria in the Extra-Amazonian Region for the Secretary for Health Surveillance from the Ministry of Health
  • , Lilian R Pratt-RiccioAffiliated withLaboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, FiocruzCentro de Pesquisa, Diagnóstico e Treinamento em Malária (CPD-Mal), Fiocruz, Reference Center for Malaria in the Extra-Amazonian Region for the Secretary for Health Surveillance from the Ministry of Health
  • , Vitor Ennes-VidalAffiliated withLaboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, Fiocruz
  • , Irene S SoaresAffiliated withDepartamento de Análises Clínicas e Toxicológicas, Universidade de São Paulo
  • , Maurício Martins RodriguesAffiliated withDepartamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo
  • , José Maria de SouzaAffiliated withPrograma de Ensaios Clínicos em Malária - Instituto Evandro Chagas, SVS
  • , Cláudio Tadeu Daniel-RibeiroAffiliated withLaboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, FiocruzCentro de Pesquisa, Diagnóstico e Treinamento em Malária (CPD-Mal), Fiocruz, Reference Center for Malaria in the Extra-Amazonian Region for the Secretary for Health Surveillance from the Ministry of Health
  • , Maria de Fátima Ferreira-da-CruzAffiliated withLaboratório de Pesquisas em Malária, Instituto Oswaldo Cruz, FiocruzCentro de Pesquisa, Diagnóstico e Treinamento em Malária (CPD-Mal), Fiocruz, Reference Center for Malaria in the Extra-Amazonian Region for the Secretary for Health Surveillance from the Ministry of Health Email author 

Abstract

Background

Plasmodium vivax merozoite surface protein-1 (MSP-1) is an antigen considered to be one of the leading malaria vaccine candidates. PvMSP-1 is highly immunogenic and evidences suggest that it is target for protective immunity against asexual blood stages of malaria parasites. Thus, this study aims to evaluate the acquired cellular and antibody immune responses against PvMSP-1 in individuals naturally exposed to malaria infections in a malaria-endemic area in the north-eastern Amazon region of Brazil.

Methods

The study was carried out in Paragominas, Pará State, in the Brazilian Amazon. Blood samples were collected from 35 individuals with uncomplicated malaria. Peripheral blood mononuclear cells were isolated and the cellular proliferation and activation was analysed in presence of 19 kDa fragment of MSP-1 (PvMSP-119) and Plasmodium falciparum PSS1 crude antigen. Antibodies IgE, IgM, IgG and IgG subclass and the levels of TNF, IFN-γ and IL-10 were measured by enzyme-linked immunosorbent assay.

Results

The prevalence of activated CD4+ was greater than CD8+ T cells, in both ex-vivo and in 96 h culture in presence of PvMSP-119 and PSS1 antigen. A low proliferative response against PvMSP-119 and PSS1 crude antigen after 96 h culture was observed. High plasmatic levels of IFN-γ and IL-10 as well as lower TNF levels were also detected in malaria patients. However, in the 96 h supernatant culture, the dynamics of cytokine responses differed from those depicted on plasma assays; in presence of PvMSP-119 stimulus, higher levels of TNF were noted in supernatant 96 h culture of malaria patient’s cells while low levels of IFN-γ and IL-10 were verified. High frequency of malaria patients presenting antibodies against PvMSP-119 was evidenced, regardless class or IgG subclass.PvMSP-119-induced antibodies were predominantly on non-cytophilic subclasses.

Conclusions

The results presented here shows that PvMSP-119 was able to induce a high cellular activation, leading to production of TNF and emphasizes the high immunogenicity of PvMSP-119 in naturally exposed individuals and, therefore, its potential as a malaria vaccine candidate.

Keywords

Malaria Plasmodium vivax MSP-119 Cellular response Antibodies