Schistosoma mansoni antigens modulate allergic response in vitro in cells of asthmatic individuals

Abstract

Schistosoma mansoni infection is associated with a low prevalence of asthma and a less severe form of the disease. The mechanisms underlying this association may include the production of regulatory cells and cytokines. The aim of this study was to evaluate the immune response induced by the S. mansoni antigens, Sm22.6, PIII, and Sm29 and their ability to suppress allergen-specific IL-5 production by peripheral blood mononuclear cells (PBMC) from asthmatic individuals. PBMCs were stimulated in vitro with S. mansoni antigens in the presence or absence of antigen-1 of the mite Dermatophagoides pteronyssinus (Der p1). Cytokines were measured in PBMC supernatants by enzyme-linked immunosorbent assay (ELISA), and the phenotype of cells producing IL-10 was assessed using flow cytometry. High production of S. mansoni antigen-specific IL-10 was observed not only in cells of S. mansoni-infected individuals, but also in cells of noninfected asthmatic individuals. In the former group, the main cellular sources of IL-10 were CD4+ CD25+, and CD14+ cells. The levels of IFN-γ, IL-5, and IL-13 in the noninfected asthmatic group were ∼100 pg/ml in response to the antigens. Moreover, when S. mansoni antigens were added to cultures stimulated with Der p1, levels of IL-10 were increased (Der p1 = 234 ± 118; Der p1 + Sm22.6 = 1189 ± 595; Derp1 + PIII = 799 ± 331; Derp1 + Sm29 = 652 ± 288 pg/ml) with reduced levels of IL-5 (Der p1 = 286 ± 219; Der p1 + Sm22.6 = 93 ± 153; Derp1 + PIII = 132 ± 188; Derp1 + Sm29 = 96 ± 86 pg/ml). The S. mansoni antigens evaluated in the present study induced the production of the regulatory cytokine IL-10 and down-modulated the Th2 immune response that participates in the pathology of asthma. Drug Dev Res 72:538–548, 2011. © 2011 Wiley-Liss, Inc.