Enteric salmonella infection inhibits Paneth cell antimicrobial peptide expression.
Paneth cells, highly secretory epithelial cells found at the bases of small intestinal crypts, release a variety of microbicidal molecules, including alpha-defensins and lysozyme. The secretion of antimicrobials by Paneth cells is thought to be important in mucosal host defense against invasion by enteric pathogens. We explored whether enteric pathogens can interfere with this arm of defense. We found that oral inoculation of mice with wild-type Salmonella enterica serovar Typhimurium decreases the expression of alpha-defensins (called cryptdins in mice) and lysozyme. Oral inoculation with Salmonella serovar Typhimurium strains that are heat killed, lack the PhoP regulon, and lack the SPI1 type III secretion system or with Listeria monocytogenes does not have this effect. Salmonella may gain a specific survival advantage in the intestinal lumen by decreasing the expression of microbicidal peptides in Paneth cells through direct interactions between Salmonella and the small intestinal epithelium.
Salzman
Nita H
NH
Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. nsalzman@mcw.edu
Chou
Margaret M
MM
de Jong
Hendrik
H
Liu
Lide
L
Porter
Edith M
EM
Paterson
Yvonne
Y
D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D005260:Female; D007410:Intestinal Diseases / Q000276:immunology*; D007421:Intestine, Small / Q000276:immunology*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D009113:Muramidase / Q000032:analysis / Q000235:genetics*; D019879:Paneth Cells / Q000276:immunology*; D011498:Protein Precursors / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D012481:Salmonella Infections, Animal / Q000276:immunology*; D012486:Salmonella typhimurium; D048051:p38 Mitogen-Activated Protein Kinases
D000900:Anti-Bacterial Agents; D011498:Protein Precursors; D012333:RNA, Messenger; C059569:cryptdin; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D009113:Muramidase