CagA/cytotoxic strains of Helicobacter pylori and interleukin-8 in gastric epithelial cell lines.

JE Crabtree, SM Farmery, IJ Lindley, N Figura… - Journal of clinical …, 1994 - jcp.bmj.com
JE Crabtree, SM Farmery, IJ Lindley, N Figura, P Peichl, DS Tompkins
Journal of clinical pathology, 1994jcp.bmj.com
AIMS--To investigate:(1) whether Helicobacter pylori directly induces interleukin-8 (IL-8)
message expression and protein secretion in established gastric epithelial cell lines; and (2)
if CagA/cytotoxin positive and negative strains of H pylori differ in their ability to induce
epithelial IL-8. METHODS--Gastric epithelial cell lines were co-cultured with H pylori NCTC
11637 and 10 clinical isolates (four cytotoxic, six non-cytotoxic) and secreted IL-8 was
measured by enzyme linked immunosorbent assay (ELISA). Specific induction of gastric …
AIMS
To investigate: (1) whether Helicobacter pylori directly induces interleukin-8 (IL-8) message expression and protein secretion in established gastric epithelial cell lines; and (2) if CagA/cytotoxin positive and negative strains of H pylori differ in their ability to induce epithelial IL-8.
METHODS
Gastric epithelial cell lines were co-cultured with H pylori NCTC 11637 and 10 clinical isolates (four cytotoxic, six non-cytotoxic) and secreted IL-8 was measured by enzyme linked immunosorbent assay (ELISA). Specific induction of gastric epithelial IL-8 mRNA was examined by reverse transcription and polymerase chain reaction (RT-PCR) amplification.
RESULTS
H pylori (NCTC 11637) induced IL-8 secretion from three gastric epithelial cell lines (KATO-3, ST42, AGS) but not from MKN 45 (gastric) or intestinal (SW480, HT29) cell lines. H mustelae did not stimulate IL-8 secretion from KATO-3, ST42, and AGS cells. H pylori induced IL-8 secretion was reduced by heat killing, sonication, freeze thawing or formalin fixation of the bacteria. CagA/cytotoxin positive strains of H pylori induced significantly higher IL-8 secretion than CagA/cytotoxin negative strains in the three positive gastric epithelial cell lines (KATO-3, ST42: p < 0.01; AGS: p < 0.02). A significant increase (p < 0.01) in the expression of IL-8 mRNA relative to G3PDH mRNA was observed in KATO-3 cells after three hours of co-culture with CagA/cytotoxin positive strains.
CONCLUSIONS
H pylori directly increases gastric epithelial IL-8 mRNA expression and IL-8 protein secretion in a strain specific manner. Induction of epithelial IL-8 by CagA/cytotoxin positive strains is likely to result in neutrophil chemotaxis and activation and thus mucosal damage. These observations on epithelial IL-8 may explain the association between CagA/cytotoxin positive strains and gastroduodenal disease.
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