Abstract

There is evidence that mast cells, basophils and IgE can contribute to immune responses to parasites, however, the relative importance of these effector elements in parasite immunity is not fully understood. Previous work in Il3-deficient and c-kit mutant Kit(W/W-v) mice indicated that interleukin-3 and c-Kit contribute to expulsion of the intestinal nematode Strongyloides venezuelensis (S.v.) during primary infection. Our findings in mast cell-deficient Kit(W-sh/W-sh) mice and two types of mast cell-deficient mice that have normal c-kit: "Hello Kitty" and MasTRECK mice, confirmed prior work in Kit(W/W-v) mice suggesting that mast cells play an important role in S.v. egg clearance in primary infections. We also assessed a possible contribution of basophils in immune responses to S.v By immunohistochemistry, we found that numbers of basophils and mast cells, were markedly increased in the jejunal mucosa during primary infections with S.v Studies in basophil-deficient Mcpt8(DTR) mice revealed a small but significant contribution of basophils to S.v. egg clearance in primary infections. Studies in mice deficient in various components of immune responses showed that CD4(+) T cells and ILC2 cells, IgG, FcR?, and to a lesser extent, IgE and Fc?RI, contribute to effective immunity in primary S.v infections. These findings support the conclusion that the hierarchy of importance of immune effector mechanisms in primary S.v. infection is: CD4(+) T cells/ILC2 cells, IgG and FcR?>mast cells>IgE and Fc?RI>basophils. By contrast, in secondary S.v infection, our evidence indicates that CD4(+) T cells are critical but mast cells, antibodies, and basophils have little or no non-redundant roles.

View details for DOI 10.1128/IAI.00053-17

View details for PubMedID 28264908