ABSTRACT
BACKGROUND: Malaria and schistosomiasis coinfection frequently occurs in tropical countries. This study evaluates the influence of Schistosoma haematobium infection on specific antibody responses and cytokine production to recombinant merozoite surface protein-1-19 (MSP1-(19)) and schizont extract of Plasmodium falciparum in malaria-infected children. METHODOLOGY: Specific IgG1 to MSP1-(19), as well as IgG1 and IgG3 to schizont extract were significantly increased in coinfected children compared to P. falciparum mono-infected children. Stimulation with MSP1-(19) lead to a specific production of both interleukin-10 (IL-10) and interferon-γ (IFN-γ), whereas the stimulation with schizont extract produced an IL-10 response only in the coinfected group. CONCLUSIONS: Our study suggests that schistosomiasis coinfection favours anti-malarial protective antibody responses, which could be associated with the regulation of IL-10 and IFN-γ production and seems to be antigen-dependent. This study demonstrates the importance of infectious status of the population in the evaluation of acquired immunity against malaria and highlights the consequences of a multiple infection environment during clinical trials of anti-malaria vaccine candidates.
Subject(s)
Antibodies, Helminth/immunology , Antigens, Protozoan/immunology , Malaria, Falciparum/immunology , Plasmodium falciparum/immunology , Schistosomiasis haematobia/immunology , Adolescent , Animals , Antibodies, Protozoan/immunology , Child , Cytokines/immunology , Humans , Malaria, Falciparum/complications , Malaria, Falciparum/parasitology , Male , Merozoite Surface Protein 1/immunology , Plasmodium falciparum/physiology , Schistosoma haematobium/immunology , Schistosoma haematobium/physiology , Schistosomiasis haematobia/complications , Schistosomiasis haematobia/parasitologyABSTRACT
This study has evaluated the individual control of isotype production and the influence of external signals that can be experimentally provided in vitro, in antibody responses to two different recombinant Schistosoma antigens (Sh28GST and TPx-1). Peripheral blood mononuclear cells or enriched B cell fractions obtained from S. haematobium infected Senegalese adults were induced to terminal differentiation in vitro. The production of antibody to either antigen was donor-dependent and for each donor it was antigen-dependent. Differentiation to IgG1 and IgG3 production, and possibly IgA, specific to these conserved parasite antigens could be regulated differentially in vitro. Exogenous IL-2 and IL-10 or IL-10 and TGF-beta led to the production of specific IgG3 or IgG1 and/or IgA, respectively. This is the first report on such experimentally induced differential regulation of antigen-specific IgG1 and IgG3. This may have implications in designing protocols for protein based-vaccinations aiming at eliciting antibody responses of certain protective-type isotypes.
