Chronic Chlamydia infection in human organoids increases stemness and promotes age-dependent CpG methylation

Abstract

Chronic infections of the fallopian tubes with Chlamydia trachomatis (Ctr) cause scarring and can lead to infertility. Here we use human fallopian tube organoids and genital Ctr serovars D, K and E for long-term in vitro analysis. The epithelial monolayer responds with active expulsion of the bacteria into the lumen and with compensatory cellular proliferation—demonstrating a role of epithelial homeostasis in the defense against this pathogen. In addition, Ctr infection activates LIF signaling, which we find to be an essential regulator of stemness in the organoids. Infected organoids exhibit a less differentiated phenotype with higher stemness potential, as confirmed by increased organoid forming efficiency. Moreover, Ctr increases hypermethylation of DNA, which is an indicator of accelerated molecular aging. Thus, the chronic organoid infection model suggests that Ctr has a long-term impact on the epithelium. These heritable changes might be a contributing factor in the development of tubal pathologies, including the initiation of high grade serous ovarian cancer.

Serologic markers of Chlamydia trachomatis and other sexually transmitted infections and subsequent ovarian cancer risk: Results from the EPIC cohort

“…A possible biologic interpretation is that the secretory cells of the distal fallopian tube might not be vulnerable to neoplastic transformation caused by infectious agents, even though one recent study suggests that C. trachomatis has long-term impact on the tubal epithelium by altering the phenotype and inducing heritable changes in the epigenome. 40 Only one prospective seroepidemiological study has analyzed the association of STI antibodies and Type II EOC finding a significant association of C. trachomatis antibodies with Type II. 22 Another explanation could be that analyses of serum antibodies do not reflect the previous infections that are crucial in malignant transformation of the secretory cells.…”

Organoids – New Models for Host–Helminth Interactions

“…Organoid systems were initially developed to recreate murine and human small intestine and colon epithelia, and involved the use of specific culture media cocktails to recreate the SCN conditions for each intestinal segment in the specific species [10,11,17]. Subsequently, organoids have been developed for a great variety of tissues and organs, including stomach, esophagus, liver, lung, pancreas, prostate, brain, kidney, mammary gland, ovary, lingual, taste bud, salivary gland, testis, endometrium, Fallopian tube, lymph nodes, blood vessels, skin, inner ear, and retina [1,2,11,[18][19][20][21]. Moreover, intestinal, mammary, keratinocyte, and liver organoids from other animal models already exist, including those of bovine, porcine, ovine, chicken, feline, and canine origin [22].…”

“…Infection with the uropathogen Enterococcus faecalis has been studied in human urothelial organoids [32]. More recently, Fallopian tube organoids have served as a model to study the long-term impact of Chlamydia trachomatis infections in the human epithelium that may contribute to the development of ovarian cancer [18].…”

Organoid technology in female reproductive biomedicine

“…Various pathogens that have been studied using organoids include Helicobacter pylori (stomach organoids) [95,96], Salmonella enterica [97] and Clostridium difficile [98] in intestinal organoids, and Zika virus (ZIKV) in human neurospheres and brain organoids [99]. Kessler et al used human fallopian tube organoids and genital Chlamydia trachomatis (C. trachomatis) serovars D, K, and E for long-term in vitro infection analysis and investigated its effect on epithelial homeostasis [100]. The epithelial organoids responded to the infection with a fast, dynamic extrusion of intact Ctr inclusions and/ or infected cells into the lumen, and with compensatory cellular proliferation that demonstrated a role for epithelial cells in the defense against this pathogen.…”