HUMAN-LEISHMANIASIS-AT-CYTOKINES.BAHIA.BR

The cell-mediated immune response is critical in the resistance to and recovery from leishmaniasis. Cytokines are central elements in mounti ng an immune response and have received a great deal of attention in b oth human and experimental leishmaniasis. IFN-gamma is responsible for macrophage activation leading to leishmanicidal mechanisms, Understan ding the balance of cytokines that lead to enhanced production of or s ynergize with IFN-gamma, and those cytokines that counterbalance its e ffects is fundamental for developing rational immunotherapeutic or imm unoprophylactic approaches to leishmaniasis, Here we focus on the cyto kine balance in human leishmaniasis, particularly IL-10 as an IFN-gamm a opposing cytokine, and IL-12 as an IFN-gamma inducer, The effects of these cytokines were evaluated in terms of several parameters of the human immune response, IL-10 reduced lymphocyte proliferation, IFN-gam ma production and cytotoxic activity of responsive human peripheral bl ood mononuclear cells. Neutralization of IL-10 led to partial restorat ion of lymphoproliferation, IFN-gamma production and cytotoxic activit y in unresponsive visceral leishmaniasis patients, IL-12 also restored the responses of peripheral blood mononuclear cells from visceral lei shmaniasis patients. The responses obtained with IL-12 are higher than those obtained with anti-IL-10, even when anti-IL-10 is combined with anti-IL-4.