Helicobacter pylori-mediated transcriptional regulation of the human beta-defensin 2 gene requires NF-kappaB.
Human beta-defensin 2 (hBD-2) is an antimicrobial peptide involved in host defence against bacterial infection in epithelial tissues. Its levels are dramatically increased after bacterial infection. The involvement of NF-kappaB in Helicobacter pylori-mediated induction of hBD-2 promoter activity was examined. A luciferase reporter plasmid containing the hBD-2 promoter extending from -2110 base pairs to -1 was transiently expressed in MKN45 cells, and promoter activity was determined after incubation with H. pylori for 6 h. Deletion or mutation of the NF-kappaB site at -208 abolished activation of the hBD-2 promoter. Only H. pylori strains carrying a cag pathogenicity island (PAI) induced activation of the NF-kappaB site of the hBD-2 promoter gene. By gel retardation analyses, H. pylori increased NF-kappaB binding to hBD-2 promoter gene sequences. Supershift analysis demonstrated that whereas H. pylori activated NF-kappaB p65-p65 and p50-p50 homodimers, and the p65-p50 heterodimer of NF-kappaB, only the p65-p65 homodimer bound to the NF-kappaB site of the hBD-2 promoter. Thus, specific NF-kappaB proteins are important cis-elements for induction of hBD-2 gene transcription by H. pylori.
Wada
A
A
Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Sakamoto, Japan.
Ogushi
K
K
Kimura
T
T
Hojo
H
H
Mori
N
N
Suzuki
S
S
Kumatori
A
A
Se
M
M
Nakahara
Y
Y
Nakamura
M
M
Moss
J
J
Hirayama
T
T
D002460:Cell Line; D005753:Gastric Mucosa / Q000382:microbiology*; D005786:Gene Expression Regulation; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D023083:beta-Defensins / Q000235:genetics*
C106641:DEFB4A protein, human; D016328:NF-kappa B; D023083:beta-Defensins