Studies on the expression of the TNF alpha receptors (p55 and p75) and their relative contributions to prostanoid production and glycolytic rate by rheumatoid synovial fibroblasts in vitro.

The effect of monoclonal antibodies against the 55- and 75-kDa (p55 and p75) tumour necrosis factor (TNF) receptors on two tumour necrosis factor alpha (TNF alpha) induced responses was studied in rheumatoid synovial fibroblasts (RSF) in vitro. This provided functional evidence for the expression of both receptor types, which was confirmed by substantial inhibition of 125I-TNF alpha binding to RSF by both antibodies. TNF alpha stimulation of prostanoid production was found to be a function of ligand binding to both receptor types, whereas the stimulation of cellular glycolysis was largely mediated via the p55 receptor. Thus, we showed that RSF express both types of TNF receptor and functional studies showed that stimulation of each receptor results in both similar and dissimilar cellular responses.