Novel in vitro effects of bucillamine - Inhibitory effects on proinflammatory cytokine production and transendothelial migration of T cells

Objective, To investigate the novel antiinflammatory mechanism of a disease -modifying antirheumatic drug, bucillamine, on activated T cells, specifica lly its effect on T cell proliferation, cytokine production, and migration of T cells, Methods. T cells were cultured in wells coated with anti-CD3 monoclonal ant ibodies (mAb) plus anti-CD26 mAb or anti-CD3 plus anti-CD28 mAb, with or wi thout bucillamine. Proliferative responses and the production of interleuki n-2 (IL-2), interferon-gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), IL-6, IL-4, and IL-5 were measured under these costimulatory condit ions. Phytohemagglutinin (PHA)-activated T cells were cultured on human umb ilical vein endothelial cell-coated transwells in the presence or absence o f bucillamine, and T cells migrating through the endothelial cell layer wer e counted. Immunofluorescence analysis was also performed to analyze the ef fect of bucillamine on the surface expression of adhesion molecules on T ce lls. Results. Bucillamine (64 mu M) significantly inhibited T cell proliferation and the production of IL-2, IFN gamma, TNF alpha, and IL-6, whereas it had no inhibitory effects on the production of IL-1 and IL-5 in the cultures w ith anti-CD3 plus anti-CD26 mAb, In contrast, bucillamine had no effects on T cell proliferation or any cytokine production in the cultures with anti- CD3 plus anti-CD28 mAb, Furthermore, the same concentration of bucillamine inhibited transendothelial migration of PHA-activated T cells, and reduced the expression level of CD44 on T cells, Conclusion. This study demonstrated the novel effects of bucillamine in vit ro, showing inhibition of type 1 T helper-type cytokine production and proi nflammatory cytokine production induced by certain costimulatory conditions , and inhibition of transendothelial migration of T cells, The inhibition o f T cell migration appeared to be mediated partly through the reduced expre ssion of CD44, an adhesion molecule on the T cell surface.