Here, we examined primary CD8 T cell responses following i.v. and oral gavage infection of C57BL/6 mice to establish a model examining the initiation of adaptive immunity to Listeria. In order to analyse Ag-specific CD8 T cell responses to Listeria infection, a recombinant Listeria strain (Listeria-OVA) that expresses a well-defined model antigen, ovalbumin (OVA), was used. Here, CD8A is linked to infection.