A distinct cellular profile is seen in the human endocervix during Chlamydia trachomatis infection

Problem The endocervix is a major target of Chlamydia trachomatis infection, but little is known about the immune repertoire in this tissue, or its response to these common bacteria. Method of study Using a cytobrush, we isolated cells from the endocervix of 20 women during C. trachomatis infection, and post‐antibiotic treatment. Endocervical swabs and blood were taken in parallel. Endocervical cells were enumerated, and endocervical and blood T cells immunophenotyped. Chlamydia trachomatis was genotyped by sequence analysis of the OmpA gene, and quantified by culture. Results Chlamydia trachomatis genotypes were D, E, F and Ia, and infectious burden varied considerably. Endocervical T cell and neutrophil numbers were highly elevated during infection, with both CD4 and CD8 T‐cell subsets accumulating. Regardless of the presence or absence of infection, the endocervical cell infiltrate was dominated by effector memory T cells, and the numbers of CCR5 and CD103 expressing T cells was significantly higher than in the blood. Human leukocyte antigen (HLA‐DR) expression by endocervical T cells was significantly increased during infection. Conclusion The human endocervix exhibits a distinct cellular response to C. trachomatis infection that can be longitudinally evaluated by cytobrush sampling. Infecting organisms can be sampled and analyzed in parallel.