研究発表を行った学会； 20th IUBMB International Congress of Biochemistry and Molecular Biology and 11th FAOBMB Congress.
　　　２００６年６月１８日〜２３日 (Kyoto)
タイトル； Increased expression of TLR2 and TLR4 during dimethylsulfoxide-induced neutrophilic differentiation of HL-60 cells
発表者；首藤　剛　氏
　　　（熊本大学　大学院医学薬学研究部　遺伝子機能応用学分野）
Abstract；
Neutrophils are the most abundant immune cells found in human blood. These cells possess a wide variety of antimicrobial functions as well as the ability to produce inflammatory cytokines against microorganisms. Recently, it has been shown that human primary neutrophils express most of the toll-like receptors (TLRs), type I transmembrane receptors that play an important role in innate immune recognition of pathogens. However, expression patterns and functions of TLRs during myeloid cell differentiation to neutrophils are unknown. Here, we show that expression of TLR2 and TLR4 genes are strongly up-regulated during dimethylsulfoxide (DMSO)-induced neutrophilic differentiation of HL-60 cells. Moreover, flowcytometry analysis revealed that surface expression of TLR2 and TLR4 were also up-regulated in DMSO-differentiated HL-60 cells (dHL-60 cells). Finally, to determine the function of these receptors in dHL-60 cells, we treated dHL-60 cells with bacterial peptidoglycan (PGN) and lipopolysaccharide (LPS), specific ligands for TLR2 and TLR4, respectively. Real-time quantitative RT-PCR analysis for IL-8 gene showed the hyperresponsiveness to PGN and LPS in dHL-60 cells, but not in undifferentiated HL-60 cells. Thus, these results suggest a differentiation-dependent increase of TLR2 and TLR4 expression, which may be associated with hyperesponsiveness to the bacterial PGN and LPS in dHL-60 cells.