Signal transduction-mediated adherence and entry of Helicobacter pylori into cultured cells.
OBJECTIVE
An ability to invade host cells could be a means for Helicobacter pylori to achieve resistance to antibiotic therapy. The aim of this study was to investigate the mechanisms involved in adherence and entry of H. pylori into cultured cells.


METHODS
Coinfection with Yersinia expressing mutant or wild-type YopH tyrosine phosphatase was used. Genistein and cytochalasin D were used as inhibitors of adherence and entry; entry was monitored by a gentamicin-protection assay. Target cells were AGS cells and a beta1-integrin-deficient cell line with its corresponding beta1-integrin-expressing transfectant.


RESULTS
H. pylori induced phosphorylation of 125-130-kilodalton proteins, similar in size to the target proteins of Yersinia YopH. Adherence of H. pylori was inhibited by Yersinia organisms expressing enzymatically active YopH but not by inactive YopH. Adherence and entry of H. pylori was considerably higher with beta1-integrin-transfected cells than with beta1-integrin-deficient cells. Antibodies directed against alpha5- and beta1-integrin chains reduced adherence to the alpha5beta1-integrin-expressing gastric cell line AGS. Entry was inhibited by both cytochalasin D and genistein. Entry, but not adherence, was higher for 2 type I strains than for a type II isolate.


CONCLUSIONS
Invasion of gastric epithelium via an integrin-mediated pathway could contribute to the ability of H. pylori to establish persistent infection.
Su
B
B
Microbiology and Tumor-Biology Center, Karolinska Institute, Stockholm, Sweden.
Johansson
S
S
Fällman
M
M
Patarroyo
M
M
Granström
M
M
Normark
S
S
D001422:Bacterial Adhesion; D015153:Blotting, Western; D002460:Cell Line; D005434:Flow Cytometry; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D015151:Immunoblotting; D019012:Integrin beta1 / Q000502:physiology*; D016023:Integrins; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases; D015398:Signal Transduction; D013270:Stomach / Q000166:cytology* / Q000382:microbiology*; D014162:Transfection; D015007:Yersinia
D019012:Integrin beta1; D016023:Integrins; D011505:Protein-Tyrosine Kinases