ABSTRACT
Interleukin-10 (IL-10) is a pleiotropic cytokine produced by monocytes/macrophages, B cells, and various subsets of T cells including T helper type 2 (Th2 ), ThO cells, and regulatory T (Tr) cells and to a lesser extent by T hl cells. IL-10 exerts diverse effects on a number of hemopoeitic cell types that include regulation of proliferation and differentiation of most immune cells. The main biological function of IL-10 appears to be immunosuppressive and anti-inflammatory in nature and therefore, it has been exploited therapeutically for the treatment of various autoimmune disorders such as inflammatory bowel disease, psoriasis and rheumatoid arthritis in Phase II and Phase III clinical trials. Studies of IL-10 manipulation by employing IL-10 knock out and IL-10 transgenic animal models have revealed a central role for IL-10 in the immunopathogenesis o f a number of infectious diseases. Overall, the results suggest that in infectious diseases wherein inflammation constitutes a critical component of pathogenesis, IL-10 appears to be playing a beneficial role by limiting the extent of inflamma tion. The significant role of IL-10 in host immune responses against infectious agents has led to phase I clinical trials in a number of human infectious diseases. To our knowledge, results of IL-10 administration in clinical trials are limited to infections with human immunodeficiency virus (HIV), hepatitis C virus (HCV) and experimental endotoxemia/sepsis. Therefore, in this review, we will discuss the role of IL-10 in the immunopathogenesis of these diseases, and describe its therapeutic potential.
