IL-10-producing Th1 cells and disease progression are regulated by distinct CD11c+ cell populations during visceral leishmaniasis

Il-10 is a critical regulatory cytokine involved in the pathogenesis of visceral leishmaniasis caused by leishmania donovani and clinical and experimental data indicate that disease progression is associated with expanded numbers of cd4+ ifnγ+ t cells committed to il-10 production. here,combining conditional cell-specific depletion with adoptive transfer,we demonstrate that only conventional cd11chi dcs that produce both il-10 and il-27 are capable of inducing il-10-producing th1 cells in vivo. in contrast,cd11chi as well as cd11cint/lo cells isolated from infected mice were capable of reversing the host protective effect of diphtheria toxin-mediated cd11c+ cell depletion. this was reflected by increased splenomegaly,inhibition of no production and increased parasite burden. thus during chronic infection,multiple cd11c+ cell populations can actively suppress host resistance and enhance immunopathology,through mechanisms that do not necessarily involve il-10-producing th1 cells. © 2012 owens et al.