Contrasting effects of Trichinella spiralis and Trichuris muris antigens on the infection by Leishmania infantum in BALB/c mice

The interaction of Trichinella spiralis and Trichuris muris derived antigens with the infection by Leishmania infantum was investigated in BALB/c mice. Infection with 106 promastigotes of L. infantum did not induce relevant serum antibody (IgG subclasses), nor cytokine (IFN-γ, IL-4) responses despite that mice could partially control the infection. Immunization with T. spiralis activated a moderate IgG1 and secondarily an IgG2a anti-leishmanial response whereas immunization with T. muris elicited only a weak and late activation of IgG1 anti-leishmanial response. Immunization with T. muris caused an elevation of serum IFN-γ levels which was drastically reinforced by the L. infantum infection, and that was accompanied by almost complete parasitological cure of infected mice. Immunization with T. spiralis induced an elevation of serum IL-4 levels but this response was greatly (about 60%) neutralized by the infection with L. infantum, and this was associated to exacerbation of the infection.