MONOCYTE-DERIVED IL-10 AND PGE(2) ARE ASSOCIATED WITH THE ABSENCE OF TH-1 CELLS AND IN-VITRO T-CELL SUPPRESSION IN LEPROMATOUS LEPROSY

Our previous studies had shown that the clinicopathological spectrum i n leprosy was associated with discrete T cell subsets in circulation, with tuberculoid patients having antigen-induced Th 1, whereas leproma tous leprosy patients with antigen-specific T cell anergy possesed Th 2 cells [1]. The present study shows that infected monocytes from lepr omatous but not tuberculoid leprosy patients released soluble factors (MoF(s)) containing IL-10 and PGE(2) which inhibited M. leprae induced in vitro lymphoproliferation of previously sensitised healthy or tube rculoid leprosy subjects. A strong negative correlation was observed b etween adherant cell derived IL-10 and IL-2 at the level of both the p roduct and cytokine mRNA. Moreover, anti-IL-10 antibodies and indometh acin partially reversed the suppressor effects of MoF(s). Taken togeth er these studies indicate that infected monocytes contribute to the de velopment of T cell anergy by releasing factors that affect regulatory cytokines and T cell subset differentiation in lepromatous leprosy.