Campylobacter jejuni induces diverse kinetics and profiles of cytokine genes in INT-407 cells

OBJECTIVE: To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger ribonucleic acid mRNA for various cytokines and chemokines in response to Campylobacter jejuni C. jejuni stimulation.

METHODS: In an experimental single-blind study, cultured embryonic human epithelial INT-407 cells were treated with different concentrations of viable C. jejuni, its sonicated, and filtered supernatant. A modified non-radioactive in situ hybridization using probe cocktails was used to measure mRNA levels for the pro-inflammatory cytokines interleukin IL-1beta, IL-6, interferon-gamma IFN-gamma, tumour necrosis factor TNF-alpha, transforming growth factor TGF-beta1, and IL-8, and the anti-inflammatory cytokines, IL-4 and IL-10. The study was carried out from September 2005 to March 2007 at the Department of Microbiology, Immunology, and Infectious Diseases, College of Medicine, Arabian Gulf University, Bahrain.

RESULTS: Viable C. jejuni, sonicated bacteria and filtered supernatant induced high mRNA expression for the pro-inflammatory cytokines IL-1beta, IL-6, IFN-gamma, TNF-alpha, TGF-beta1, and IL-8, which peaked at the 12 hours post stimulation. Anti-inflammatory cytokines IL-4 and IL-10 mRNA expression were induced maximally at 3 hours post stimulation mainly by sonicated bacteria and filtrated supernatant, however, not with living bacteria. Untreated embryonic human epithelial INT-407 cells expressed low amount of mRNA for the various cytokines and chemokines at all time points. For each cytokine, 4 samples were used per time hour.

CONCLUSION: This study demonstrated that embryonic human epithelial INT-407 cells in response to viable C. jejuni or its cytotoxins can alter cytokine and chemokine mRNA expression patterns and kinetics suggesting a potential role for theses mediators in the immunopathogenesis of the infection caused by this pathogen, which might be relevant for future immunotherapeutic interventions during severe bacterial infections.