To this end, we performed transcriptional profiling of CD4+CD25+ T cells isolated from the spleens of B. bronchiseptica infected and control mice on day 7 post infection, when peak bacterial loads were detected (acute infection); and day 42 post infection, when B. bronchiseptica specific CD4+ T cells, as well as Treg, were systemically detectable (carriage) (Figure 3d). This evidence concerns the gene CD4 and infection.