Toll-like receptor 4 agonist, lipopolysaccharide, increases the expression levels of cytokines and chemokines in human peripheral blood mononuclear cells

Toll-like receptors (TLRs) are members of the pattern recognition receptor family and are essential in the innate immune response. In total, 11 TLRs exist in humans, which are expressed in a variety of cells, including peripheral blood cells. TLR4 plays a significant role in the defense against gram-negative pathogens by recognizing the lipopolysaccharide (LPS) molecules in these bacteria. The aim of the present study was to detect the expression level variation of a number of major immune molecules in peripheral blood mononuclear cells (PBMCs) stimulated by LPS, in order to identify candidate genes involved in the biological functions mediated by TLR4. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis and an antibody chip were performed in the current study. The RT-qPCR results revealed a marked enhancement in the expression levels of various molecules, including cytokines, chemokines, growth factors and protein kinases. In addition, the antibody chip identified the increased secretion of crucial proinflammatory molecules in the supernatants collected from LPS-treated PBMCs. In conclusion, a large number of molecules were found to be involved in TLR4-mediated functions.