Escherichia coli induces transuroepithelial neutrophil migration by an intercellular adhesion molecule-1-dependent mechanism.
During bacterial infections at mucosal sites, neutrophils migrate to the mucosa and cross the epithelial barrier. We have examined neutrophil migration across Escherichia coli-stimulated uroepithelial cell layers in an attempt to more fully understand this process. Stimulation of uroepithelial cells with E. coli or interleukin-1 alpha (IL-1 alpha) induced transepithelial neutrophil migration in a time- and stimulant dose-dependent manner. Uroepithelial cell lines and nontransformed uroepithelial cells expressed intercellular adhesion molecule-1 (ICAM-1) but not ICAM-2, E-selectin, or P-selectin. Epithelial ICAM-1 expression was enhanced after stimulation with E. coli or IL-1 alpha. Anti-ICAM-1 antibody reduced transepithelial neutrophil migration by 61 to 85%, indicating that neutrophils bound ICAM-1 on the epithelial surface. Antibodies to CD18 and CD11b reduced migration by 70 to 79%, suggesting that CD11b/CD18 (Mac-1) was acting as the neutrophil receptor for ICAM-1 in this process. Anti-CD11a antibodies had no effect on neutrophil migration. In conclusion, E. coli induced ICAM-1- and Mac-1-dependent transepithelial neutrophil migration. Previous studies have shown that urinary tract epithelial cells secrete IL-8 when exposed to E. coli or IL-1 alpha. These observations suggest that epithelial cells play an active role in neutrophil migration during urinary tract infections.
Agace
W W
WW
Department of Medical Microbiology, Lund University, Sweden.
Patarroyo
M
M
Svensson
M
M
Carlemalm
E
E
Svanborg
C
C
D018821:CD18 Antigens / Q000502:physiology; D002465:Cell Movement; D004926:Escherichia coli / Q000502:physiology*; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology*; D008070:Lipopolysaccharides / Q000633:toxicity; D009504:Neutrophils / Q000502:physiology*; D014551:Urinary Tract / Q000276:immunology*; D014552:Urinary Tract Infections / Q000276:immunology
D018821:CD18 Antigens; D008070:Lipopolysaccharides; D018799:Intercellular Adhesion Molecule-1