The CD40–CD154 system in anti-infective host defense

Research in the past few years has documented significant advances in our understanding of the CD40–CD40 ligand (CD154) system in diverse immune functions. This system influences many T cell mediated inflammatory immune responses and effector functions, unmasking a previously unexpected role for CD40–CD154 in cell mediated immunity. Manipulation of CD154 in animal models of infection by the use of CD154-deficient mice or anti-CD154 antibodies has shown the importance of this systemin the initiation of the inflammatory response, in the activation of antigen-presenting cells and in resistance to infections.