Secretion of microbicidal alpha-defensins by intestinal Paneth cells in response to bacteria.
Paneth cells in mouse small intestinal crypts secrete granules rich in microbicidal peptides when exposed to bacteria or bacterial antigens. The dose-dependent secretion occurs within minutes and alpha-defensins, or cryptdins, account for 70% of the released bactericidal peptide activity. Gram-negative bacteria, Gram-positive bacteria, lipopolysaccharide, lipoteichoic acid, lipid A and muramyl dipeptide elicit cryptdin secretion. Live fungi and protozoa, however, do not stimulate degranulation. Thus intestinal Paneth cells contribute to innate immunity by sensing bacteria and bacterial antigens, and discharge microbicidal peptides at effective concentrations accordingly.
Ayabe
T
T
Department of Pathology, College of Medicine, University of California, Irvine, CA 92697, USA.
Satchell
D P
DP
Wilson
C L
CL
Parks
W C
WC
Selsted
M E
ME
Ouellette
A J
AJ
D000818:Animals; D004926:Escherichia coli / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology / Q000378:metabolism; D008050:Lipid A / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D020783:Matrix Metalloproteinase 7 / Q000235:genetics / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D019879:Paneth Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D011498:Protein Precursors / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology; D013682:Teichoic Acids / Q000276:immunology
D008050:Lipid A; D008070:Lipopolysaccharides; D011498:Protein Precursors; D013682:Teichoic Acids; C059569:cryptdin; C009900:lipoteichoic acid; D020783:Matrix Metalloproteinase 7