Three-dimensional organotypic models of human colonic epithelium to study the early stages of enteric salmonellosis.
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.
Höner zu Bentrup
Kerstin
K
Department of Microbiology and Immunology, Program in Molecular Pathogenesis and Immunity, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
Ramamurthy
Rajee
R
Ott
C Mark
CM
Emami
Kamal
K
Nelman-Gonzalez
Mayra
M
Wilson
James W
JW
Richter
Emily G
EG
Goodwin
Thomas J
TJ
Alexander
J Stephen
JS
Pierson
Duane L
DL
Pellis
Neal
N
Buchanan
Kent L
KL
Nickerson
Cheryl A
CA
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
D016209:Interleukin-8