A disconnect between precursor frequency, expansion potential, and site-specific CD4+ T cell responses in aged mice
Adult and old C57Bl/6 mice were infected i.v. with 107 CFU LmE641-OVA in 100μl PBS. On day 6 post-infection, pooled spleen plus lymph node cells were incubated with E641:I-Ab, OVA:I-Ab and MCC:I-Ek tetramers, enriched, and analyzed as in Fig 1. (A) Absolute number of responding E641:I-Ab+, OVA:I-Ab−, MCC:I-Ek− CD4+ T-cells in adult and old mice (ns p>0.05; Mann-Whitney). The average number of cells (±SEM) is shown below the respective label. (B) Representative concatenated contour plot showing BrdU incorporation by E641:I-Ab only cells in adult and old mice. Numbers indicate percent (±SEM) E641:I-Ab+ CD4+ T cells in the respective gates. Shown are the aggregate results of two experiments with 3–4 mice/group.