SELECTIVE INDUCTION OF INTERLEUKIN-4-PRODUCING AND INTERFERON-GAMMA-PRODUCING T-CELLS FROM CORD-BLOOD NAIVE T-CELLS - EFFECTS OF COSTIMULATORY SIGNALING THROUGH CD28

We investigated the effect of costimulation through CD28 and CD11a on the differentiation of human naive CD4(+) T cells with restricted cyto kine production profiles. Interleukin (IL)-4 and interferon-gamma (IFN -gamma) were measured by ELISA and IL-2 was detected by a bioassay. Na ive CD4(+) T cells proliferated and produced IL-2 upon cross-linking o f CD3, and costimulation through CD28 enhanced IL-2 production. After repeated stimulation, CD4(+) T cells which were stimulated in the abse nce of costimulation through CD28 lost their ability to secrete IL-2 a nd started secreting IL-4 and IFN-gamma. Instead in the presence of co stimulation through CD28, they secreted IL-2, IL-4 and IFN-gamma. Bloc king of endogenous IL-4 activity with anti-IL-4 Ab suppressed the IL-4 secretion and prolifeation of T cells.