| Abstrakt: |
ABSTRACTTrypanosoma cruzi(Y strain)-infected interleukin-4−/−(IL-4−/−) mice of strains 129/J, BALB/c, and C57BL/6 showed no significant difference in parasitemia levels or end point mortality rates compared to wild-type (WT) mice. Higher production of gamma interferon (IFN-γ) by parasite antigen (Ag)-stimulated splenocytes was observed only for C57BL/6 IL-4−/−mice. Treatment of 129/J WT mice with recombinant IL-4 (rIL-4), rIL-10, anti-IL-4, and/or anti-IL-10 monoclonal antibodies (MAbs) did not modify parasitism. However, WT mice treated with rIL-4 and rIL-10 had markedly increased parasitism and suppressed IFN-γ synthesis by spleen cells stimulated with parasite Ag, concanavalin A, or anti-CD3. Addition of anti-IL-4 MAbs to splenocyte cultures from infected WT 129/J, BALB/c, or C57BL/6 mice failed to modify IFN-γ synthesis levels; in contrast, IL-10 neutralization increased IFN-γ production and addition of rIL-4 and/or rIL-10 diminished IFN-γ synthesis. We conclude that endogenous IL-4 is not a major determinant of susceptibility to Y strain T. cruziinfection but that IL-4 can, in association with IL-10, modulate IFN-γ production and resistance. |
