The influence of leflunomide on cell cycle, IL-2-receptor (IL-2-R) and its gene expression

Leflunomide is a novel immunomodulatory drug shown to be very effective in animal models of autoimmune diseases and transplantation rejection, as well as in human rheumatoid arthritis. Leflunomide's main metabolite, A77 1726, has been shown to be reversibly antiproliferativein vitro. Pursuing this, we performed cell cycle analysis by flow cytometry of a B-cell lymphoma line and found that at concentrations >2.5 μM cells accumulated in the early S-phase. In order to determine A77 1726's effects on cell activation, human peripheral blood lymphocytes (PBL) were cultured in the presence of PHA or OKT 3 antibody. Flow cytometric evaluation of IL-2 and transferrin receptor expression exhibited a …