CCL5 and infection: We tested the hypothesis that CCL5 is essential for inducing adaptive mucosal immunity against Chlamydia. We conclude that CCL5 supports the induction of Th1 cytokine and IgG2a Ab as well as IgA Ab responses against Chlamydia. The suppression of CCL5 correlated with delayed clearance of C. muriduram infection, which suggests chlamydial immunity is mediated by Th1 immune responses driven in part by CCL5.