Helicobacter pylori tumor necrosis factor-α inducing protein promotes cytokine expression via nuclear factor-κB.
OBJECTIVE
To study the effects of Helicobacter pylori (H. pylori) tumor necrosis factor-α (TNF) inducing protein (Tip-α) on cytokine expression and its mechanism.


METHODS
We cloned Tip-α from the H. pylori strain 26695, transformed Escherichia coli with an expression plasmid, and then confirmed the expression product by Western blotting. Using different concentrations of Tip-α that affected SGC7901 and GES-1 cells at different times, we assessed cytokine levels using enzyme-linked immunosorbent assay. We blocked SGC7901 cells with pyrrolidine dithiocarbamate (PDTC), a specific inhibitor of nuclear factor κB (NF-κB). We then detected interleukin (IL)-1β and TNF-α levels in SGC7901 cells.


RESULTS
Western blot analysis using an anti-Tip-α antibody revealed a 23-kDa protein, which indicated that recombinant Tip-α protein was recombined successfully. The levels of IL-1β, IL-8 and TNF-α were significantly higher following Tip-α interference, whether GES-1 cells or SGC-7901 cells were used (P < 0.05). However, the levels of cytokines (including IL-1β, IL-8 and TNF-α) secreted by SGC-7901 cells were greater than those secreted by GES-1 cells following treatment with Tip-α at the same concentration and for the same duration (P < 0.05). After blocking NF-κB with PDTC, the cells (GES-1 cells and SGC-7901 cells) underwent interference with Tip-α. We found that IL-1β and TNF-α levels were significantly decreased compared to cells that only underwent Tip-α interference (P < 0.05).


CONCLUSIONS
Tip-α plays an important role in cytokine expression through NF-κB.
Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China.
Chun-Li
CL
Tang
Bo
B
Hao
Guo-Xin
GX
Zhang
Rui-Hua
RH
Shi
Wen-Fang
WF
Cheng
D001426:Bacterial Proteins / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D053583:Interleukin-1beta / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D011759:Pyrrolidines / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D013859:Thiocarbamates / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D001426:Bacterial Proteins; D016207:Cytokines; D053583:Interleukin-1beta; D016209:Interleukin-8; D016328:NF-kappa B; D011759:Pyrrolidines; D013859:Thiocarbamates; C505332:Tipalpha protein, Helicobacter pylori; D014409:Tumor Necrosis Factor-alpha; C020972:pyrrolidine dithiocarbamic acid
Helicobacter pylori; Interleukin-1β; Interleukin-8; Nuclear factor-κB; Tumor necrosis factor-α; Tumor necrosis factor-α inducing protein