Figure 11. CD4-depletion reduces Tbet and IFNγ production in WT mice similar to levels seen in RANTES^−/− mice.

A cohort of WT and RANTES^−/− mice were depleted of CD4 T cells with GK1.5 antibody on the day prior to infection with LCMV clone 13. T cell responses were examined 35 days later. (A and B) Percentages and total numbers of LCMV-specific CD8 T cells were determined in WT and RANTES^−/− mice depleted of CD4 T cells for both D^bGP33-specific and D^bGP276-specific CD8 T cells using tetramer. (C) D^bGP33 and D^bGP276-specific CD8 T cells were examined for expression of PD1, LAG3 and 2B4. Filled grey represents naïve CD8 T cells, blue = DbGP33-specific CD8 T cells from WT mice, red = DbGP33-specific CD8 T cells from RANTES^−/− mice. (D) Representative plots of CD107a expression and IFNγ production by D^bGP33-specific CD8 T cells. Numbers represent the percent of CD107a+ cells that are also making IFNγ in response to stimulation with GP33-44 peptide. Viral titers were determined by plaque assays in CD4-depleted WT and RANTES^−/− mice (E). Tbet expression was determined in D^bGP33-specific CD8 T cells by flow cytometry in WT and RANTES^−/− mice containing CD4 T cells as well as those depleted of T cells prior to infection (F). Tbet expression was already slightly reduced by 8 days p.i. (G).