STIMULATION OF HUMAN SYNOVIAL FIBROBLAST DNA-SYNTHESIS BY RECOMBINANT HUMAN CYTOKINES

Abstract

The pronounced synovial hyperplasia often found in rheumatoid joints can be explained at least partially, by the interaction of monocyte-macrophage polypeptides (monokines) and lymphocyte polypeptides (lymphokines) with synovial fibroblast-like cells. We now report that purified recombinant human cytokines, interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor alpha, tumor necrosis factor beta (or lymphotoxin) and, to a variable extent, interferon-gamma, stimulate the DNA synthesis of human synovial fibroblast-like cells cultured in low (i.e., 1%) fetal bovine serum. With the exception of interferon-gamma, the effects of the cytokines were generally elevated by indomethacin, suggest..