Resolution of Chlamydia trachomatis Infection Is Associated with a Distinct T Cell Response Profile
ABSTRACTChlamydia trachomatisis the causative agent of the most frequently reported bacterial sexually transmitted infection, the total burden of which is underestimated due to the asymptomatic nature of the infection. UntreatedC. trachomatisinfections can cause significant morbidities, including pelvic inflammatory disease and tubal factor infertility (TFI). The human immune response againstC. trachomatis, an obligate intracellular bacterium, is poorly characterized but is thought to rely on cell-mediated immunity, with CD4+and CD8+T cells implicated in protection. In this report, we present immune profiling data of subjects enrolled in a multicenter study ofC. trachomatisgenital infection. CD4+and CD8+T cells from subjects grouped into disease-specific cohorts were screened using aC. trachomatisproteomic library to identify the antigen specificities of recall T cell responses after natural exposure by measuring interferon gamma (IFN-γ) levels. We identified specific T cell responses associated with the resolution of infection, including unique antigens identified in subjects who spontaneously cleared infection and different antigens associated withC. trachomatis-related sequelae, such as TFI. These data suggest that novel and uniqueC. trachomatisT cell antigens identified in individuals with effective immune responses can be considered as targets for vaccine development, and by excluding antigens associated with deleterious sequelae, immune-mediated pathologies may be circumvented.