Helicobacter pylori infection of human gastric epithelial cells induces IL-8 and TNF alpha, but not TGF beta 1 mRNA

Helicobacter pylori (Hp) infection causes gastric carcinomas. The mechanism s of these diseases are not known but Hp induction of cytokines is believed to be involved. However, the profile as weil as the involvement of cytokin es induced by Hp infection is less clear. In the present study, steady stat e levels of interleukin-8 (IL-8), tumor necrosis factor-alpha. (TNF alpha) and TGF beta 1 mRNA of human gastric epithelial cell lines Kato III, AGS an d NCI-87N in response to Hp infection were investigated, The cell cultures were infected with Hp for up to 18 h. Total RNA was extracted and analyzed by reverse transcription-PCR. The three cell lines rested expressed low con stitutive levels of mRNA for IL-8;Ind TNFa. The mRNA levels of IL-8 quickly increased within 2 h in all three cells tested and reached a peak at 4 h f ollowing infection with Hp. In contrast, the levels of TNF alpha after Hp i nfection increased in only Kato III cells. The other cells, AGS and NCI-87N , responded with minimum increases after Hp infection. The TGF beta 1 mRNA was constitutively expressed in both ACS and NCI-87N cells, but Kato Ill ce lls expressed only low levels prior to infection. The lip infection did not increase the levels of TGF beta 1 mRNA as well as TGF beta 1 secretion in all cells tested. These results indicate that the cytokine response to Hp i nfection differs according to the cells studied and the response may bi lin ked somewhat to TGF levels of gastric cells. (C) 2000 Federation of Europea n Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.