CD11c: not merely a murine DC marker, but also a useful vaccination target.

The induction of robust CD4(+) and CD8(+) T cell responses is a central aim in antiviral and anticancer vaccination. To this end, dendritic cells (DC) need to capture the vaccine, process and present it on MHC class I and II molecules. The mechanisms by which DC acquire antigen predetermine the quantity and quality of the ensuing T cell activation. In this issue of the European Journal of Immunology, it is demonstrated that targeting antigen towards CD11c, an integrin expressed preferentially by murine DC, facilitates efficient CD4(+) and CD8(+) T cell activation. The underlying mechanisms involve efficient antigen delivery into the marginal zone and T/DC zone of the spleen. This commentary discusses these findings in the context of current knowledge on antigen presentation.