Rheumatoid arthritis T cells produce Th1 cytokines in response to stimulation with a novel trispecific antibody directed against CD2, CD3, and CD28

Rheumatoid arthritis (RA) T cells respond poorly to conventional mitogens. We have examined the proliferative and cytokine responses of T cells to a synthetic trispecific antibody (Tsab) directed against CD2, CD3, and CD28. In 11 subjects RA T cells proliferated more, and secreted significantly more IL-2, in response to Tsab than did control peripheral blood (PB) cells. Very high levels of IL-2 were produced by 2 patients with aggressive disease. Measurement of intracellular IL-2, IFN-gamma, IL-4, and IL-5 by flow cytometry showed a Th1 pattern of cytokine production in 13 RA and 9 control subjects. We conclude that RA T cells are not irreversibly inactivated, and that spatial arrangement of stimulating molecules may be important in eliciting maximal responses.