IL-4–producing B cells regulate T helper cell dichotomy in type 1- and type 2-controlled diseases

Abstract

Significance Cutaneous leishmaniasis and schistosomiasis are neglected tropical diseases for which there are no effective vaccines and limited treatment strategies. To develop vaccine and therapeutic alternatives, a detailed understanding of host immunity is essential. We show a role for IL-4Rα–responsive B cells in host susceptibility to Leishmania major and protection against Schistosoma mansoni infection through the production of early IL-4, which in turn regulates Th2 cell polarization and disease outcome in mice. These important findings highlight the significant impacts that B cell-specific IL-4Rα and IL-4 responsiveness have in the context of type 1 ( L. major ) and type 2 ( S. mansoni ) pathogens. Thus, vaccine and therapeutic development should aim to target both B and T cell immunity for optimal efficacy.