Development of B-cell memory and effector function

The past year has seen significant advances in our understanding of molecules that both positively and negatively regulate B- and T-cell responses. Of particular interest is the lethal phenotype of CTLA-4 deficient mice, which has illuminated the importance of downregulation of T-cell responses and the increasingly complicated role of CD40 and its ligand in directing both T- and B-cell priming.