首页 | 本学科首页   官方微博 | 高级检索  
     


The role of phagocytosis in IL-8 production by human monocytes in response to lipoproteins on Staphylococcus aureus
Authors:Kang Hee Jung  Ha Jeong-Mi  Kim Han Sung  Lee Haneulnari  Kurokawa Kenji  Lee Bok Luel
Affiliation:aDept. of Laboratory Medicine, Hallym University College of Medicine, Anyang-si, Gyeonggi-do 431-070, Republic of Korea;bNational Research Lab. of Defense Proteins, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
Abstract:Cytokine responses to microbes are triggered by pattern recognition receptors, such as Toll-like receptors (TLRs), which sense pathogen-associated molecular patterns. Cell wall-associated triacylated lipoproteins in Staphylococcus aureus are known to be native TLR2 ligands that mediate host inflammatory responses against S. aureus. However, the mechanism by which these lipidated lipoproteins, which are buried under the thick S. aureus cell wall, work to stimulate TLR2 remains unclear. Heat-killed wild type S. aureus cells activated human monocytic THP-1 cells to produce proinflammatory cytokines, including interleukin (IL)-8, whereas the lipoprotein lipidation-deficient lgt mutant induced less than an eighth of the amount of IL-8 induced by the wild type. IL-8 induction in response to heat-killed S. aureus cells in THP-1 cells was not inhibited by a blocking antibody against cell surface TLR2, suggesting that intracellular TLR2 might be involved in the induction of IL-8 by S. aureus lipoprotein. The relationship between phagocytosis and IL-8 production in THP-1 cells was analyzed on a single-cell level by flow cytometry using fluorescein-labeled S. aureus cells and phycoerythrin-labeled anti-IL-8 antibody. Production of intracellular IL-8 was correlated with phagocytosis of S. aureus cells in THP-1 cells and in human peripheral blood mononuclear cells. Opsonization of S. aureus cells enhanced both the phagocytosis of S. aureus cells and the production of intracellular IL-8 in THP-1 cells. These results suggest that lipidated lipoproteins on S. aureus cells stimulate human monocytes after phagocytosis.
Keywords:Abbreviations: PRR, pattern-recognition receptor   TLR, Toll-like receptor   IL, interleukin   PAMP, pathogen-associated molecular pattern   LPS, lipopolysaccharide   Lgt, lipoprotein diacylglycerol transferase   Lnt, lipoprotein N-acyl transferase   Δlgt, lgt gene deletion   PBS, phosphate buffered saline   PBMC, peripheral blood mononuclear cell   FBS, fetal bovine serum   TNF, tumor necrotizing factor   MOI, multiplicity of infection   PE, phycoerythrin   MFI, mean fluorescence intensities
本文献已被 ScienceDirect PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号