The contributions of various dendritic cell (DC) subsets to the generation of effector versus memory CD8+ T cells remains unclear. In Immunity, Lin et al. show that lung CD103+ or CD11b+ migratory DCs activate naive CD8+ T cells differently during infection with influenza virus. Through the use of mice deficient in CD103+ DCs, the authors show this DC subset is required for the efficient generation of virus-specific CD8+ T cells with an effector or effector-memory phenotype in the lymph nodes and the migration of those cells to the lungs. However, the generation of CD8+ T cells with a central memory phenotype is supported mostly by the CD11b+ DC subset. CD103+ DCs have tenfold higher expression of CD24, which serves as a costimulatory ligand for the differentiation of effector CD8+ T cells at least in part through capture of the alarmin HMGB1 and engagement of the receptor RAGE on CD8+ T cells. Thus, different intrinsic properties of DCs dictate the outcome of the effector or memory differentiation of CD8+ T cells.

Immunity 40, 400–413 (2014)