Abstract

T cell activation initiated via the CD3/TCR complex requires signals provided by the interaction between costimulatory receptors on T cells and their corresponding ligands on accessory cells. Human dermal fibroblasts are reported to be deficient in this costimulatory activity and normally cannot serve as accessory cells for activation of resting T cells. We examined the contribution of human synovial fibroblasts to costimulatory activity for resting T cells.