A disconnect between precursor frequency, expansion potential, and site-specific CD4+ T cell responses in aged mice
C57Bl/6 mice were infected with 1000 PFU 385–99 WNV, sc (foot pad). ndLN, dLN and the spleen were harvested on day 8 post-infection for lymphocyte analysis by flow cytometry (FCM). Representative gating strategy for CD4+ tetramer+ T cells via live, forward and side scatter, CD3+ T cells, CD8α- CD4+ T cells and E641:I-Ab+ CD4+ T cells harvested from (A) ndLN, (B) dLN, and (C) spleen are shown on day 8 post-WNV infection. Absolute numbers of E641:I-Ab+ CD4+ T cells in adult and old C57BL/6 and DEREG mice enumerated for (D) ndLN, (E) dLN, and (F) spleen are shown as labeled. (G) Percent CD4+ INF-γ+ T cells in dLN of adult and old C57BL/6 and DEREG mice. Shown are the aggregate results of two experiments with (A-F) 6–9 mice/group and (G) 5–8 mice/group. Each dot represents a single mouse (*p<0.05; **p<0.01; Mann-Whitney).