CD8A and infection: Our data on the antigen presenting capacities of NK cell subsets ex vivo, as well as the colocalization of NK cells and naïve CD8 T cells in the central lymphoid organs at early time points post infection favour the theory that CD8 T cell responses were partially reduced because of the depletion of B220−NK cells and IKDCs, as direct actors in the process of antigen presentation to naive antigen-specific CD8 T cells.