Vaginal bacteria elicit acute inflammatory response in fallopian tube organoids: a model for pelvic inflammatory disease

OBJECTIVE: To facilitate in vitro mechanistic studies in pelvic inflammatory disease (PID) and subsequent tubal factor infertility, as well as ovarian carcinogenesis, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection. DESIGN: Experimental study. SETTING: Academic medical and research center. PATIENTS: FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases. INTERVENTIONS: We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhessea vaginae. MAIN OUTCOME MEASURES: The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes. RESULTS: Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae. Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in F. vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids. CONCLUSION: Patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful model system to study the host-pathogen interaction during bacterial infection which may facilitate mechanistic investigations in PID and its contribution to tubal factor infertility and ovarian carcinogenesis.