Kinetics of T-cell immune response following B microti infection in Townes SS and control mice. (A-B) Flow cytometric analysis of T_FH cells in Townes SS and control AA and AS mice following B microti infection. (A) Representative FACS plots for CXCR5 and PD1 expression gated on splenic CD4⁺ T cells. (B) Quantification of T_FH cells (CD4⁺CXCR5^hiPD1^hi) (n = 2-6). Combined data from 3 independent experiments. (C) Representative FACS plots for CD44 and IL21 expression gated on splenic CD4⁺ T cells. (D) Quantification of IL21⁺ cells in the spleens from AA, AS, and SS mice. (E) Representative FACS plots for CD44 and IFNγ expression gated on splenic CD4⁺ T cells. (F) Quantification of IFNγ⁺ cells gated in the spleens from AA, AS, and SS mice. Each symbol represents data from an individual mouse. Error bars indicate the mean ± SEM. ***P < .001; by unpaired 2-tailed Student t test.