Characterization of IL-22 and IL-17 Expressing Leukocytes in the Cervix

Problem: Identification of the types of cells that produce IL-17 and IL-22 in the genital tract can clarify the roles that these cytokines play in responses to pathogens. Method of study: We isolated and stimulated cells from cervical tissue to identify and characterize cytokine-producing cells. Results: Upon stimulation of CD3⁺ CD4⁺ endocervical cells, 1.6, 3.4, and 1.5% were induced to produce IL-22, IL-17, and both cytokines, respectively. Stimulation of CD3⁺ CD4⁺ ectocervical cells resulted in 3.3% IL-22⁺, 5.5% IL-17⁺ and 2.6% IL-22⁺ IL17⁺ cells. CD45⁺ CD3^- cells had relatively high endogenous levels of cytokine expression that did not increase upon stimulation. Innate lymphoid cells (ILCs) made up 5.7-8% of CD45⁺ cervical cells and stimulation caused increases in IL-17 and IL-22. Conclusion: These studies show that the majority of the CD45⁺ leukocytes that can be induced to produce IL-22 and IL-17 in cervix are CD3⁺ CD4⁺, but ILCs are also present and can make both cytokines.