CD4 T cell polyfunctionality inversely correlates with host susceptibility to C. muridarum in the FRT.

(A) WT and Bhlhe40^-/- mice were infected intravaginally with 1×10⁵ C. muridarum. Cytokine levels in the supernatants of ex vivo cultures of DLN and FRT cells as measured at 10 dpi. Data are from two independent experiments with 9 mice per group. Each data point represents an individual mouse. (B-D) WT, Bhlhe40^-/-, Bhlhe40^-/- x Il10^-/- and Il10^-/- mice were infected intravaginally with 1×10⁵ C. muridarum. Representative FACS plots (B), SPICE analysis (C) and summary data (D) depicting cytokine producing CD4 T cells (gated on live CD90.2⁺CD4⁺CD44^hiIL-10^- cells) at 14 dpi. Data are from two independent experiments with 6–9 mice per group. Each data point represents an individual mouse. (E-F) Chlamydia-specific TP1 CD4 T cell adoptive transfer experiment (see workflow in Fig 2I). Representative FACS plots (E) and summary data (F) of cytokine-producing Bhlhe40^-/- TP1 (CD45.2⁺CD90.1^-), WT TP1 (CD45.2⁺CD90.1⁺) and B6 host CD4 T cells (CD45.2^-CD90.1^-) in the host FRT. Data are from two independent experiments with 6 samples per group. Each data point represents a pooled FRT sample from 4 mice. (G) Polyfunctionality Index (left) and bacterial burdens (right) in WT, Bhlhe40^-/-, Bhlhe40^-/- x Il10^-/- and Il10^-/- mice. Data are from two independent experiments with 6–9 mice per group. Each data point represents an individual mouse. Error bars represent the mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001 by unpaired t test in (A), (D) and (G), and paired t test in (F).