Abstract
Background: In our previous study we found that rhsIL-6R, along with recombinant human interleukin-6, plays a regulatory role in the immune response by modulating the tumour necrosis factor-α (TNF-α) expression and its production by peripheral blood mononuclearcells (PBMC). We also suggested that sIL-6R with IL-6 secreted by human PMN (neutrophils) influenced the TNF-α expression and its production by autologous PBMC.Aims: Since soluble gp130 (sgp130) is a natural inhibitor for sIL-6R/interleukin-6 responses, in the present study we estimated an effect of exogenous recombinant human sgp130 and sgp130 secreted by PMN on the TNF-α expression and its production by PBMC.Methods: Cells were isolated from whole blood of healthy persons. The PMN were cultured in 96-well plates for 1 h at 37°C in a humidified incubator with 5% CO2. After the incubation, the culture supernatant of PMN was removed and added to the PBMC. PBMC were incubated for 1 h at 37°C in the same conditions. Cytoplasmic protein fractions of PMN and, for comparative purpose of PBMC, were analysed for presence of sgp130 by western blotting with the use of monoclonal antibody capable of detecting this protein. In the culture supernatants of PMN we examined the concentrations of sgp130 by human enzyme-linked immunosorbent assay. TNF-α was measured at the protein levels as well as the mRNA levels.Results and conclusions:The present results revealed that exogenous recombinant human sgp130 modulates the TNF-α expression and production by PBMC. In contrast, we did not find any effect of sgp130 secreted by PMN on the TNF-α expression and its production by autologous PBMC.