Current status of clinical development of interleukin-10.

Communication between cells in the lymphohematopoietic system is mediated by soluble molecules called cytokines. Lymphoid and myeloid cells are the cellular targets and source of these regulatory molecules. Interleukin-10 seems to be a main factor of a negative feedback system that inhibits synthesis of proinflammatory cytokines and of colony-stimulating factors in a variety of cells. Considering the cytokine synthesis-inhibiting action of interleukin-10 in activated macrophages, T cells, neutrophils, and eosinophils, many of the biologic effects of interleukin-10 may result in immunosuppression. Recently, the interleukin-10 receptor and some signal transduction events following interleukin-10 binding have been characterized. Substantial progress has also been made in providing the experimental basis for interleukin-10 therapy in various diseases. In vitro and preclinical studies suggest that interleukin-10 may prove quite useful in clinical settings in which overexpression of cytokines is likely to play an important role in pathogenesis, including inflammatory bowel disease, acute pancreatitis, septic shock, and certain malignancies.