Møller Anne-Sophie W, Øvstebø Reidun, Westvik Ase-Brit, Joø Gun Britt, Haug Kari-Bente F, Kierulf Peter
Department of Clinical Chemistry, The Research and Development Group, Ullevaal University Hospital, N-0450 Oslo, Norway.
J Endotoxin Res. 2003;9(6):349-60. doi: 10.1179/096805103225002791.
Regulation of chemokine production and the expression of chemokine receptors play an important role during inflammation and infectious diseases. The present study was designed to study the effects of five different bacterial cell wall components (PAMPs) on the production of MCP-1 and MIP-1alpha and the expression of CCR2 by highly purified human blood monocytes. All five PAMPs induced high expression of mRNA and protein synthesis of both chemokines. Generally, MCP-1 mRNA and protein levels were higher than MIP-1alpha levels. Expression of MCP-1 and MIP-1alpha differed both at the mRNA and at the protein levels, MIP-1alpha always showing a more rapid initial increase, attaining lower protein levels than MCP-1. Antibodies against CD14 significantly inhibited the inducing effects of all the PAMPs used. Antibody against TLR2 inhibited the chemokine production induced by LTA and AraLAM by more than 36% (P < 0.05) while chemokine production induced by Escherichia coli-LPS, purified E. coli-LPS and Neisseria meningitidis-LPS was inhibited by more than 60% by antibody against TLR4 (P < 0.05). The inducing effects of all five PAMPs could be inhibited by rIL-4, rIL-10 and rIL-13. rIL-4 was the most effective. Generally, IC(50) of these anti-inflammatory cytokines were lower for the MIP-1alpha than for the MCP-1 production. The cell surface expression of CCR2 was significantly down-regulated by all five PAMPs in addition to a decrease in cytosolic free calcium and binding of rMCP-1. We conclude that MCP-1 and MIP-1alpha as well as the MCP-1 receptor CCR2 will be substantially regulated upon monocyte contact with various cell wall components (PAMPs) from Gram-negative and Gram-positive bacteria as well as from mycobacteria.
趋化因子产生的调节以及趋化因子受体的表达在炎症和感染性疾病过程中发挥着重要作用。本研究旨在探讨五种不同细菌细胞壁成分（病原体相关分子模式，PAMPs）对高度纯化的人血单核细胞产生单核细胞趋化蛋白-1（MCP-1）和巨噬细胞炎性蛋白-1α（MIP-1α）以及对CCR2表达的影响。所有五种PAMPs均诱导这两种趋化因子的mRNA高表达和蛋白质合成。一般来说，MCP-1的mRNA和蛋白质水平高于MIP-1α水平。MCP-1和MIP-1α在mRNA和蛋白质水平上均存在差异，MIP-1α总是显示出更快的初始增加，但达到的蛋白质水平低于MCP-1。抗CD14抗体显著抑制了所有所用PAMPs的诱导作用。抗Toll样受体2（TLR2）抗体对脂磷壁酸（LTA）和海藻糖二甲酰胺（AraLAM）诱导的趋化因子产生的抑制作用超过36%（P<0.05），而抗TLR4抗体对大肠杆菌脂多糖（Escherichia coli-LPS）、纯化的大肠杆菌脂多糖和脑膜炎奈瑟菌脂多糖（Neisseria meningitidis-LPS）诱导的趋化因子产生的抑制作用超过60%（P<0.05）。所有五种PAMPs的诱导作用均可被重组白细胞介素-4（rIL-4）、重组白细胞介素-10（rIL-10）和重组白细胞介素-13（rIL-13）抑制。rIL-4最为有效。一般来说，这些抗炎细胞因子对MIP-1α产生的半数抑制浓度（IC50）低于对MCP-1产生的IC50。除了细胞溶质游离钙减少和重组单核细胞趋化蛋白-1（rMCP-1）结合减少外，所有五种PAMPs均显著下调CCR2的细胞表面表达。我们得出结论，单核细胞与革兰氏阴性菌、革兰氏阳性菌以及分枝杆菌的各种细胞壁成分（PAMPs）接触后，MCP-1、MIP-1α以及MCP-1受体CCR2将受到显著调节。
