The selective triggering of CD40 on keratinocytes in vivo enhances cell-mediated immunity.

CD40 is expressed on a wide array of hematopoietic and non-hematopoietic cells, including keratinocytes. The pivotal in vivo function of CD40 on hematopoietic cells in the regulation of both humoral and cell-mediated immunity is well established. However, whether CD40 expression on non-hematopoietic cells influences immunity has until now not been addressed.