Multidimensional phenotypic immune profiling of Chlamydia trachomatis infected women using mass cytometry platform.

Chlamydia trachomatis (CT) is the most frequently reported bacterial sexually transmitted infection in the U.S., with 1 in 20 sexually active young women being infected. Infections are easily curable with antibiotics, but reinfections are frequent and infection can lead to reproductive tract sequelae. Adaptive immune responses generated during infection likely limit extent of infection, but frequently fail to prevent reinfection. We developed a 35 marker CyTOF panel to phenotype PBMCs. We examined PBMCs from women infected with CT alone (N=8), women with CT co-infected with gonorrhea or Mycoplasma genitalium (N=6), and from these same women 1 month post antibiotic treatment, and compared them to 11 healthy uninfected women. Compared to uninfected women, the frequency of B cells was increased in CT-infected women and remained elevated at 1 month, with no effects observed on various B cell subsets. Among T cells, Th1 and Tc1 percentages were reduced in CT-infected women and remained low at 1 month. Th2 and Th17 phenotype percentages were not different than uninfected women. Th1/Th2/Th17 cells expressing CD107a were reduced in CT-infected women, but rebounded towards normal at 1 month. Myeloid DCs were reduced in CT-infected women, but rebounded towards normal at 1 month. All of these differences were present regardless of coinfection. CD107a+ NK cells were reduced in CT-only infected women and failed to rebound at one month. The reductions in these various cell types is likely due to their trafficking to the infected tissue. CyTOF analysis of PBMCs from additional patients and of endometrial biopsy samples from these same subjects should provide important data related to the female host response to CT.