SUMMARY
BACKGROUND: Interleukin-18 (IL-18) and Tumor Necrosis Factor-alpha (TNF-a) are proinflammatory cytokines that increased the development of Th1 immune response, but have a different type of regulation of the gene expression. Whereas TNF-a has an inducible expression, IL-18 is translated as an inactive protein and required proteolytic cleavage by Casp-1 in inflammasome complexes.AIM: To investigate the effect of the histone deacetylases inhibitor Suberoylanilide Hydroxamic Acid (SAHA) on the gene expression and secretion of both cytokines, IL-18 and TNF-a, according to their contribution to the cancer development and anticancer immunity.METHODS: Isolated peripheral blood mononuclear cells (PBMC) were stimulated with LPS and C3bgp with or without SAHA. Cytokine production was assessed by ELISA at 6 and 24h.RESULTS: IL-18 and TNF-a secretion was significantly increased at 6h and 24h in response to stimulation. TNF-a production from stimulated PBMC was downregulated by SAHA at 6 and 24h. Treatment with SAHA does not inhibit the secretion of IL-18 significantly either at 6 or 24h of stimulation.CONCLUSION: The inhibition of histone deacetylases by SAHA does not influence the inflammasome-dependent production of immunologically active IL-18. In contrast, the production of proinflammatory TNF-a in cultures was mediated by the activity of HDAC class I and class II enzymes.