Antigen-specific CD8+ T cells respond to Chlamydia trachomatis in the genital mucosa.

Following sexual transmission, Chlamydia trachomatis specifically targets genital tract epithelial cells. Because epithelial cells are readily recognized by CD8+ T cells, the response of CD8+ T cells to Chlamydia infection has been explored in a number of studies. It has been shown that CD8+ T cells are present in the genital tracts of mice following C. trachomatis infection, but the specificity of these T cells has remained undefined. To determine whether Chlamydia-specific CD8+ T cells migrate to the genital tract in response to Chlamydia infection, we generated retrogenic mice that express a TCR specific for a Chlamydia-specific T cell Ag CrpA. T cells from the retrogenic mice were transferred into naive recipient animals to increase the frequency of Chlamydia-specific T cells to a level at which they could be tracked during primary infection. We observed that the Chlamydia-specific retrogenic T cells proliferated in lymph nodes draining the genital tract in response to genital infection with C. trachomatis. Furthermore, we found that these cells acquired the ability to produce IFN-gamma and migrated into the genital mucosa of the infected mice.