The degree of invasiveness of Campylobacter jejuni influences cytokines induction in the human monocytic cell line THP-1
Abstract number: P960
Al-Muraikhy A., Tabbara K., Botta G.
Background:Campylobacter jejuni can cause enteritis that is associated with an acute inflammatory response. C. jejuni can penetrate the intestinal epithelial barrier and interact with leucocytes, inducing proinflammatory cytokines. The severity of clinical symptoms is related to strain differences. We studied the in vitro invasiveness of eight human isolates of C. jejuni, which possess three, two, or none of the virulence genes cdtB, ciaB and iam, with the human monocytic cell line THP-1 and determined the levels of cytokines (IL-1, IL-6, IL-8, IL10, IL 12 and TNF) induced.
Methods: The invasion assay was carried out in 24 wells plate with a multiplicity of infection of 200:1 for 90 minutes followed by treatment with Gentamicin for 120 minutes. Cells were lysed with 0.01% triton and plated to determine the intracellular organisms /cell. Semi quantitative RT-Multiplex PCR was used to assess the kinetics of cytokine mRNA expression in similarly infected cells and ELISA for cytokine levels.
Results: Invasiveness directly correlated with possession of virulence genes, with the most invasive isolates possessing all three genes, followed by those possessing cdtB and ciaB, followed by those with cdtB and iam, while the least invasive were those lacking all three genes. As for cytokine mRNA expression, TNF was most significantly correlated with invasiveness, with IL-1 and IL-8 closely following, while expression of IL-6, IL-10 and IL-12 was essentially similar for all isolates. Cytokine protein expression on the other hand showed a significant difference between one of the most invasive and least invasive of the isolates with respect to TNF and IL-8 and lower differences with respect to IL-1.
Conclusion:C. jejuni infection of monocytoid cells triggers expression of proinflammatory cytokines, most significant of which is TNF. This appears to correlate with the virulence of the isolate and might be responsible for the severity of pathology and symptoms.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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