Secretion of cytokines by uroepithelial cells stimulated by Escherichia coli and Citrobacter spp.

Urinary tract epithelial cells (T 24/83) are able to express interleukin (I L)-61 IL-X, platelet-derived growth factor (PDGF) and tumour necrosis facto r-sc, but not IL-1 beta. IL-2, IL-4 and IL-IO in response to an infection w ith uropathogenic bacteria. The process of cytokine secretion is time depen dent. with a significant increase in the cytokine activity after 60 min. Th e expression of virulence factors of the bacteria does not seem to play a r ole. The interaction between bacterial products (e.g. lipopolysaccharide) a nd/or bacterial adhesion mediated by adhesins and specific receptor molecul es of cell surfaces may be responsible for the activity of mediator protein expression in the epithelial cells. The release of PDGF acid IL-8 was foun d to be higher when due to Escherichia coli HE 101 trough form than that ca used by other bacterial strains. Citrobactor CB 3009 provoked the highest l evel of IL-6. The PDGF level correlated significantly with IL-6 and IL-8 va lues (Pe 0.001). There was a significant correlation between the time-depen dent release of IL-6 and IL-8 (P < 0.05). In epithelial cytokine response t o bacterial infection. the reaction of the epithelial cells may modify them selves (e.g. internalization of bacteria) and the immune-regulatory process es that are caused by infection and responsible for parenchymal injury. <(c )> 2001 Published by Elsevier Science B.V and International Society of Chem otherapy. All rights reserved.