Murine Endometrial Organoids to Model Chlamydia Infection

Abstract

The obligate intracellular bacterium Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infections. Once internalized in host cells, C. trachomatis undergoes a biphasic developmental cycle within a membrane-bound compartment, known as the inclusion. Successful establishment of the intracellular niche relies on bacterial Type III effector proteins, such as Inc proteins. In vitro and in vivo systems have contributed to elucidating the intracellular lifestyle of C. trachomatis, but additional models combining the archetypal environment of infection with the advantages of in vitro systems are needed. Organoids are three-dimensional structures that recapitulate the microanatomy of an organ's epithelial layer, bridging the gap between in vitro and in vivo systems. Organoids are emerging as relevant model systems to study interactions between bacterial pathogens and their hosts. Here, we took advantage of recently developed murine endometrial organoids (EMOs) and present a C. trachomatis-murine EMO infection model system. Confocal microscopy of EMOs infected with fluorescent protein-expressing bacteria revealed that inclusions are formed within the cytosol of epithelial cells. Moreover, infection with a C. trachomatis strain that allows for the tracking of RB to EB transition indicated that the bacteria undergo a full developmental cycle, which was confirmed by harvesting infectious bacteria from infected EMOs. Finally, the inducible gene expression and cellular localization of a Chlamydia Inc protein within infected EMOs further demonstrated that this model is compatible with the study of Type III secreted effectors. Altogether, we describe a novel and relevant system for the study of Chlamydia-host interactions.

Establishment of Adenomyosis Organoids as a Preclinical Model to Study Infertility

“…Previous studies in the field of reproductive medicine have relied on organoids such as 3D in vitro models to study endometrial physiology and disease [60,63,[65][66][67]. In this regard, organoids have been exploited in the study of defective endometrial proliferation, such as endometriosis or endometrial cancer [63,68], disorders affecting decidualization [67], endocrine disruptors [67], or gynecological infections [69,70]. In addition, its potential in personalized medicine or as a source of biological material in regenerative therapy is becoming increasingly evident [71][72][73].…”

Organoids of the Female Reproductive Tract: Innovative Tools to Study Desired to Unwelcome Processes

“…With the emergence of multidrug-resistant sexually transmitted diseases, it is of paramount importance to have preclinical models to study host-microbe interplay, query treatments for infections, and develop regenerative therapies in case of surgical resections (Harris et al, 2018). Infection with Chlamydia trachomatis has recently been modeled in human FT organoids as well as in mouse endometrial organoids (Kessler et al, 2019;Bishop et al, 2020). Acute infection triggered a sustained response of inflammation and homeostatic repair.…”

Biomaterial strategies for the application of reproductive tissue engineering

“…The endometrial model is a good platform for studying embryo gestation and dynamic changes during the menstrual cycle. In the work of Boretto and his co-workers, processed tissue fragments of uterine horns have been cultured in 70% Matrigel, as a 3D extracellular matrix, to develop an endometrial organoid [ 55 ] and Bishop et al then followed this research to model chlamydia infection in endometrium [ 108 ]. Besides, Matrigel is also the main biomaterials used in other organoids to study the human female reproductive tract like fallopian tubes and cervix [ 104 , 108 , 109 ].…”