title: Three-dimensional organotypic models of human colonic epithelium to study the early stages of enteric salmonellosis.
abstract: In vitro cell culture models used to study how Salmonella initiates disease at the intestinal epithelium would benefit from the recognition that organs and tissues function in a three-dimensional (3-D) environment and that this spatial context is necessary for development of cultures that more realistically resemble in vivo tissues/organs. Our aim was to establish and characterize biologically meaningful 3-D models of human colonic epithelium and apply them to study the early stages of enteric salmonellosis. The human colonic cell line HT-29 was cultured in 3-D and characterized by immunohistochemistry, histology, and scanning electron microscopy. Wild-type Salmonella typhimurium and an isogenic SPI-1 type three secretion system (TTSS) mutant derivative (invA) were used to compare the interactions with 3-D cells and monolayers in adherence/invasion, tissue pathology, and cytokine expression studies. The results showed that 3-D culture enhanced many characteristics normally associated with fully differentiated, functional intestinal epithelia in vivo, including better organization of junctional, extracellular matrix, and brush-border proteins, and highly localized mucin production. Wild-type Salmonella demonstrated increased adherence, but significantly lower invasion for 3-D cells. Interestingly, the SPI-I TTSS mutant showed wild-type ability to invade into the 3-D cells but did not cause significant structural changes to these cells. Moreover, 3-D cells produced less interleukin-8 before and after Salmonella infection. These results suggest that 3-D cultures of human colonic epithelium provide valuable alternative models to study human enteric salmonellosis with potential for novel insight into Salmonella pathogenesis.
authors.affiliation: Department of Microbiology and Immunology, Program in Molecular Pathogenesis and Immunity, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Höner zu Bentrup
authors.forename: Rajee
authors.initials: R
authors.lastname: Ramamurthy
authors.forename: C Mark
authors.initials: CM
authors.lastname: Ott
authors.forename: Kamal
authors.initials: K
authors.lastname: Emami
authors.forename: Mayra
authors.initials: M
authors.lastname: Nelman-Gonzalez
authors.forename: James W
authors.initials: JW
authors.lastname: Wilson
authors.forename: Emily G
authors.initials: EG
authors.lastname: Richter
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Goodwin
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Alexander
authors.forename: Duane L
authors.initials: DL
authors.lastname: Pierson
authors.forename: Neal
authors.initials: N
authors.lastname: Pellis
authors.forename: Kent L
authors.initials: KL
authors.lastname: Buchanan
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Nickerson
mesh_terms: D001422:Bacterial Adhesion; D018929:Cell Culture Techniques; D003106:Colon / Q000166:cytology / Q000382:microbiology*; D003593:Cytoplasm / Q000382:microbiology; D019073:HT29 Cells; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000166:cytology / Q000382:microbiology*; D008855:Microscopy, Electron, Scanning; D009940:Organoids / Q000737:chemistry / Q000166:cytology / Q000382:microbiology* / Q000648:ultrastructure; D012486:Salmonella typhimurium / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology
chemical_list: D016209:Interleukin-8