Action of cyclosporin A on mononuclear phagocytes.

Classically, cyclosporin A has been reported to exert its immunomodulatory action through its effect on T lymphocytes by inhibiting the synthesis of interleukin 2. However, the inhibition of T-lymphocyte activation does not suitably account for all the effects observed following cyclosporin A administration. It is possible that some of them could be due to the action of cyclosporin A on other cells, among which are mononuclear phagocytes. This article offers a detailed review of the consequences of the interaction of cyclosporin A on the capacities (surface antigen expression and production of inflammatory mediators), functions (chemotaxis, phagocytosis, intracellular destruction and cytotoxicity) and actions (antimicrobial defense, antitumor defense and immune cooperation) of these cells. The general conclusion is that the capacities, functions and actions of the macrophages related to non-specific defense are more resistant to cyclosporin A than those related to immunoregulation.