Wu C-H, Hsieh S-C, Yu H-S, Lee K-J, Lu M-C, Tsai C-Y, Yu C-L
Department of Internal Medicine, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan.
Inflamm Res. 2006 Mar;55(3):92-8. doi: 10.1007/s00011-005-0058-5.
Anti-CD45 antibody exhibits multiple biological effects on human mononuclear cells (MNC) and polymorphonuclear neutrophils (PMN). We intended to determine whether anti-CD45 antibody could affect arachidonic acid metabolism and thereby, the interactions between human naïve MNC and PMN.
Human naïve MNC and PMN were incubated with monoclonal anti-human CD45 IgG F(ab')(2) antibody or non-specific IgG F(ab')(2) for 30 min. The mRNA expression of cyclooxygenase type 1 (COX-1), type 2 (COX-2), 5-lipoxygenase (5-LOX) and leukotriene A(4) hydrolase (LTA(4) hydrolase) in both cells was detected by RT-PCR and quantified by densitometric determination. The presence of COX-1 and COX-2 molecules in the cells was detected by Western blot. The concentration of PGE(2) and LTB(4) in cultured supernatants was measured by EIA kits.
Anti-CD45 IgG F(ab')(2) up-regulated LTA(4) hydrolase mRNA expression and LTB(4) production, but down-regulated COX-1 and COX-2 mRNA expression and PGE2 production, of naïve MNC compared to non-specific IgG F(ab')(2). In contrast, a reverse modulation by the specific antibody on PMN was observed including up-regulation of cyclooxygenase pathway and down-regulation of lipoxygenase pathway.
A novel activity of anti-CD45 with reverse modulation on cyclooxygenase/lipoxygenase pathways was found such that the expression of COX-1 and COX-2 in PMN, and 5-LOX and LTA(4) hydrolase in MNC were enhanced.
抗CD45抗体对人单核细胞（MNC）和多形核中性粒细胞（PMN）具有多种生物学效应。我们旨在确定抗CD45抗体是否会影响花生四烯酸代谢，进而影响人未成熟MNC与PMN之间的相互作用。
将人未成熟MNC和PMN与单克隆抗人CD45 IgG F(ab')(2)抗体或非特异性IgG F(ab')(2)孵育30分钟。通过逆转录聚合酶链反应（RT-PCR）检测两种细胞中环氧合酶1型（COX-1）、2型（COX-2）、5-脂氧合酶（5-LOX）和白三烯A(4)水解酶（LTA(4)水解酶）的mRNA表达，并通过光密度测定法定量。通过蛋白质印迹法检测细胞中COX-1和COX-2分子的存在。使用酶免疫分析试剂盒测量培养上清液中前列腺素E2（PGE(2)）和白三烯B4（LTB(4)）的浓度。
与非特异性IgG F(ab')(2)相比，抗CD45 IgG F(ab')(2)上调了未成熟MNC的LTA(4)水解酶mRNA表达和LTB(4)产生，但下调了COX-1和COX-2 mRNA表达以及PGE2产生。相反，观察到特异性抗体对PMN有反向调节作用，包括上调环氧合酶途径和下调脂氧合酶途径。
发现抗CD45在环氧合酶/脂氧合酶途径上具有反向调节的新活性，从而增强了PMN中COX-1和COX-2以及MNC中5-LOX和LTA(4)水解酶的表达。
