Jz. Huang et al., STIMULATION OF INTERLEUKIN-8 PRODUCTION IN EPITHELIAL-CELL LINES BY HELICOBACTER-PYLORI, Infection and immunity, 63(5), 1995, pp. 1732-1738
Following exposure to Helicobacter pylori cells, epithelial cell lines
secreted interleukin-6 (IL-6) and IL-8 but not tumor necrosis factor
alpha, Purified IL-6 alone did not stimulate IL-8 production from the
cell lines tested, indicating that IL-6 was not an intermediary in IL-
8 induction. Enhanced IL-8 secretion occurred in a time- and dose-depe
ndent manner. None of 12 antibiotics tested exhibited a significant ef
fect on IL-8-inducing activity, suggesting that preformed antigens wer
e responsible for stimulating IL-8 secretion in vitro. Live bacterial
cells caused the highest level of stimulation. Proteinase-digested and
heated (56 or 100 degrees C) cells had significantly reduced stimulat
ory activities. Purified H. pylori lipopolysaccharide, but not exopoly
saccharide, stimulated low-level secretion of IL-8, but only at high c
oncentrations, while a water-extracted H. pylori antigen preparation w
as strongly stimulatory for HEp-2 cells. No reduction in IL-8-stimulal
ory activity was observed for H. pylori mutants negative for urease ac
tivity, production of a major lipoprotein, and motility. The noncytoto
xic strain CCUG 915 stimulated lower IL-8 levels than other isolates.
However, the otherwise isogenic cytotoxin-negative mutant 17874 Delta
vacA (S. H. Phadnis, D. Ilver, L. Janzon, S. Normark, and T. U. Westbl
om, Infect. Immun. 62:1557-1565, 1994) had the same IL-8-stimulatory a
bility as the parent strain, suggesting that surface proteins other th
an the vacuolating cytotoxin are involved in IL-8 stimulation.