Evaluation of mouse enteroids as a model for Lawsonia intracellularis infection

Abstract

Lawsonia intracellularis , an obligate intracellular bacterium, is an important enteric pathogen in pig herds and horse farms worldwide. The hallmark feature of L. intracellularis infection is the proliferation of epithelial cells in intestinal crypts. A major limitation to the study of L. intracellularis infection is the lack of an in vitro model that reproduces the changes observed in proliferative enteropathy. Here we investigated the suitability of mouse enteroids as a model to study L. intracellularis infection. Mouse enteroids were microinjected with L. intracellularis , filter-sterilized L. intracellularis culture supernatant, or sterile cell culture media (DMEM). L. intracellularis antigen was detected in mouse enteroids by immunohistochemistry and was located mostly in the basal region of the epithelium. There was no differential growth of enteroids among treatment groups, and cellular proliferation was not increased in L. intracellularis -infected enteroids in relation to non-infected enteroids based on immunofluorescence staining. L. intracellularis infection did not induce changes in gene expression of Ki - 67 (proliferation marker), Sox9 (marker for transit amplifying cells) and Muc2 (marker for goblet cells). These results indicate that although L. intracellularis antigen is detectable in mouse enteroids, indicating susceptibility to infection, mouse enteroids fail to replicate the cellular proliferation and gene expression changes observed in proliferative enteropathy. Nevertheless, we have successfully demonstrated that mouse enteroids can be used to model days-long intracellular pathogen infection, serving as potential models for the study of other pathogens of interest in veterinary medicine.

Occurrence of Lawsonia intracellularis in horses raised in three regions of the state of Paraná, Brazil

“…Lawsonia intracellularis is a gramnegative, curved bacterium capable of causing clinical disease in pigs, rabbits, hamsters and horses. It is an obligate intracellular agent that affects mainly cells in the proliferative zone of the intestine (crypt cells) (Gelberg, 2017;Resende et al, 2019).…”

“…The bacterium causes a disease known as proliferative enteropathy (Resende et al, 2019). Infected crypt cells have their multiplication rate increased and cell differentiation inhibited, which leads to hyperplasia with simultaneous thickening of the intestinal mucosa the ileum, mainly (Zachary, 2017).…”

In vitro models to evaluate ingestible devices: Present status and current trends

“…Enteroids have been developed from primarily human [244][245][246][247][248][249][250][251] and murine [252][253][254][255] primary tissue. Induced human intestinal organoids have also been reported [256][257][258][259] and human fetal intestinal organoids [260].…”

“…Interestingly, a study of rotavirus infection in induced human intestinal organoids also showed infection of mesenchymal cells [256]. Additionally, studies have covered Salmonella [252,257], E. Coli [258], avian influenza [253], human adenoviruses [248] and SARS-CoV-2 [261], L. intracellularis [254] parasitic infection [246] and a diverse range of enteroviruses were tested by Drummond et al (2017) [260]. Human enteroids and intestinal organoids may therefore be useful as physiologically relevant universal culture models to study ingestible device that may deliver therapeutics that act against enteroviruses.…”

Evaluation of host and bacterial gene modulation during Lawsonia intracellularis infection in immunocompetent C57BL/6 mouse model

“…The pathogenesis of PE has been studied after challenging experimental pigs and foals using L. intracellularis isolates grown in vitro [ 13 ] or mouse enteroids [ 14 ]. There have been only a few studies reporting successful L. intracellularis infection of laboratory rodents and chickens, and the infection produced different disease outcomes [ 15 ]; however, hamsters have been reported to be both naturally and experimentally infected with L. intracellularis .…”