At 14- and 24-hr post-infection, the number of bacteria within the CD8α+ DC subset (Fig. 5A), as well as within the unfractionated total splenocyte population (Fig. 5B), was significantly reduced (10-fold at 12 h) in aged mice, whereas, by 48 h post-infection, bacterial burdens were similar, suggesting robust replication of Lm in both old and adult DC. This evidence concerns the gene CD8A and infection.