engleski

IL-18 synergizes IL-12 in inducing B cells to produce interferon-gamma

IL-18 has been described as a costimulatory factor to IL-12 for interferon (IFN)-gamma production in T cells, SAC-activated B cells, and NK cells. Here we ask how IL-18 impacts upon the IL-12-driven change in phenotype of B cells engaged in signaling via BCR and CD40, key components in the initiation of T cell-dependent B cell responses. As IL-12's actions on B cells are dependent upon endogenous production of IFN-gamma, we also determined the influence of IL-18 on IFN-gamma expression. We found that, in contrast to IL-12, exogenous IL-18 - either alone or when added together with IL-12 - did not further modulate CD23 expression in B cells that were either unstimulated or engaged in signaling via BCR and CD40. Neither of these cytokines had any effect on the expression of CD5. IL-18 alone also failed to reproduce the effect of IL-12 on IFN-gamma expression in activated B cells, but it significantly increased IL-12-stimulated IFN-γ production. IL-10 dampened these synergistic actions of IL-12 and IL-18. Our results indicate that, during T cell dependent B cell responses, human B cells require stimulation with IL-12 to become responsive to IL-18.

nije evidentirano

nije evidentirano