FIG. 2.

Persistent E. muris infection does not lead to T-cell dysfunction or exhaustion. (A) Significantly higher percentages of Ehrlichia-specific IFN-γ-secreting CD4⁺ T cells were present in the spleens of untreated mice persistently infected with E. muris than in E. muris-primed mice treated with doxycycline on day 36 after primary infection. (B) Compared to E. muris-primed mice treated with doxycycline, untreated mice persistently infected with E. muris had significantly greater absolute numbers of Ehrlichia-specific IFN-γ-producing CD4⁺ and CD8⁺ T cells in the spleen. The data are representative of two experiments. Three mice per group were included for analysis. Asterisks indicate significant differences from the naive group. *, P < 0.01; ***, P < 0.001.