Interleukin-6 −174 promoter polymorphism does not influence IL-6 production after LPS and IL-1β stimulation in human umbilical cord vein endothelial cells

The IL-6 is a typical pleiotropic cytokine, which regulates T cell response, B cell differentiation and immunoglobulin production. Endothelial cells can produce large amounts of IL-6. SNP at position −174 (G/C) in the IL-6 promoter region was found to be associated with a series of complex diseases. In this study we analyzed whether IL-6 −174 G/C polymorphism has any effect on IL-6 production of in vitro cultured HUVECs. Thirty-three fresh umbilical cords were recruited from healthy pregnancies. The endothelial cells isolated from human umbilical cords were genotyped for IL-6 −174 SNP. C allele frequency was 0.379. The IL-6 production of each primary HUVEC line was measured after IL-1β or LPS treatment by ELISA. Serial dilutions of the stimulating agents were applied and maximum amount of produced IL-6 (Rmax) and stimulator concentrations at half-maximal IL-6 response (MR50) were calculated for each of the cell lines. IL-6 production was not associated with IL-6 −174 SNP genotypes or with presence of C allele. Our results showed that IL-6 production of HUVEC after proinflammatory stimulation was not influenced by IL-6 −174 SNP. Further functional studies are required to compare differences and similarities in IL-6 −174 SNP dependent expression of IL-6 among various cell types.