T Cells and Dendritic Cells Get Intimate

Dendritic cells (DCs) are capable of both antigen presentation and CD4 T cell activation. A study in this week9s issue by Rissoan and colleagues, discussed in the Perspective by Bottomly, now shows one way in which DCs determine the selectivity of the T cell immune response. Myeloid-like DCs produce interleukin-12, which skews T cell differentiation toward a T helper 1 (T1) response, whereas lymphoid-like DCs favor a T2 response.