Mucus production, host-microbiome interactions, hormone sensitivity, and innate immune responses modeled in human endo- and ecto-cervix chips

Abstract

Modulation of mucus production by the human endo- and ecto-cervical epithelium by steroid hormones and associated interactions with commensal microbiome play a central role in the physiology and pathophysiology of the female reproductive tract. However, most of our knowledge about these interactions is based on results from animal studies or in vitro models that fail to faithfully mimic the mucosal environment of the human cervix. Here we describe microfluidic organ-on-a-chip (Organ Chip) models of the human cervical mucosa that recreate the cervical epithelial-stromal interface with a functional epithelial barrier and produce abundant mucus that has compositional, biophysical, and hormone-responsive properties similar to the living cervix. Application of continuous fluid flow to chips lined with primary human cervical epithelial cells from a commercial source that contained a mixture of primary human ecto- and endo-cervical epithelial cells promoted preferential expression of the ecto-cervical phenotype, whereas use of periodic flow including periods of stasis induced endo-cervical specialization. When the periodic flow Cervix Chips were co-cultured with living Lactobacillus crispatus and Gardnerella vaginalis bacterial communities to respectively mimic the effects of human host interactions with optimal (healthy) or non-optimal (dysbiotic) microbiome associated with an ascending infection in the female reproductive tract, significant differences in tissue innate immune responses, barrier function, cell viability and protein profile, and mucus composition were detected reminiscent of those observed in vivo. Thus, these Organ Chip models of human cervix provide a physiologically relevant experimental in vitro model to study cervical mucus physiology and its role in human host-microbiome interactions as well as a potential preclinical testbed for development of therapeutic interventions to enhance womens health.