Suppression of Helicobacter pylori-induced interleukin-8 production in vitro and within the gastric mucosa by a live Lactobacillus strain.
BACKGROUND
Accumulating evidence indicates that interleukin-8 (IL-8) plays a major role in the mucosal inflammation caused by Helicobacter pylori infection. The purpose of the present study was to examine whether Lactobacillus gasseri OLL2716 (LG21) can inhibit the H. pylori-induced production of IL-8.


METHODS
A coculture system including MKN45 cells, H. pylori, and LG21 was established for an in vitro analysis. Biopsy specimens were obtained from H. pylori-infected human subjects consisting of 19 men and six women.


RESULTS
When LG21 was 1/100 less than H. pylori in a coculture system, LG21 significantly suppressed both the IL-8 mRNA and protein generation in the coculture. Live, but not heat- or UV-treated LG21, could exert the suppressive effect. However, this amount of LG21 could not suppress either the adhesion of H. pylori to the cell surface or the IL-8 production by tumor necrosis factor-alpha, which induces IL-8 generation through the activation of the transcription. These results thus suggest that LG21 suppresses an event leading to IL-8 production, which is specific for H. pylori-induced IL-8 generation, and this event is located upstream from the IL-8 transcription but downstream from the adhesion. The measurement of the IL-8 level using gastric biopsy specimens from H. pylori-infected subjects demonstrated that LG21 also suppresses the production of IL-8 in the gastric mucosa.


CONCLUSIONS
Live LG21 were found to suppress H. pylori-induced IL-8 production in both a gastric cell line and within gastric mucosa.
Tamura
Akira
A
Laboratory for Infectious Diseases, Tokai University Medical School, Bohseidai, Isehara, Japan.
Kumai
Hideshi
H
Nakamichi
Noboru
N
Sugiyama
Toshirou
T
Deguchi
Ryozo
R
Takagi
Atsusi
A
Koga
Yasuhiro
Y
D000328:Adult; D000368:Aged; D000818:Animals; D001706:Biopsy; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D018920:Coculture Techniques; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology*; D007778:Lactobacillus / Q000378:metabolism*; D008297:Male; D051379:Mice; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
D016209:Interleukin-8; D016328:NF-kappa B