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 with 1000 PFU 385–99 WNV, sc (shoulder blades). Brain and spleens were harvested on day 10 post-infection and lymphocytes were analyzed by flow cytometry. (A) Representative gating strategy for CD4+ tetramer+ T cells via forward and side scatter, live, CD3+ T cells, CD8α- CD4+ T cells and E641:I-Ab+ CD4+ T cells harvested from brain on day 10 post-WNV infection. Absolute numbers of (B) CD3+ CD4+ T cells and (C) E641:I-Ab+ CD4+ T cells and (D) Foxp3+ Tregs in the brain are shown as labeled. Results are representative of one of three experiments. Each dot represents a single mouse (*p<0.05; Mann-Whitney).