FIG 7.

RORγt is essential for rescuing the intracellular bacterium mutant to achieve long-lasting colonization in mouse colon. Wild-type C57BL/6J mice (a and b), T-bet knockout mice (T-bet^−/− [c and d]), RORγt knockout mice (RORγt^−/− [e and f]), CCR6 knockout mice (CCR6^−/− [g and h]), and NCR1 knockout mice (NCR1^gfp/gfp or NKp46^−/− [i and j]) were intracolonically infected with the intracellular bacterium mutant at 1 × 10⁷ IFU. On days 3 and 7 and weekly thereafter, rectal swabs were taken (panels a, c, e, g, and i), or on day 28, mouse tissues were harvested (b, d, f, h, and j), as indicated along the x axis for monitoring live chlamydial organisms as shown along the y axis. Mouse tissues include different segments of gastrointestinal tract and extra-GI tract tissues as described in the Fig. 1 legend. Note that T-bet^−/− only extended the colonization of the mutant for an additional 1 week while RORγt^−/− fully rescued the mutant colonization, although neither CCR6 nor NKp46 was required for clearing the mutant. P < 0.01, Wilcoxon rank sum (area-under curves for IFU comparison between C57BL6/J and RORγt^−/− mice [n = 3 to 5 from 2 or 3 independent experiments).