The anti-TNF-α antibody infliximab indirectly regulates PECAM-1 gene expression in two models of in vitro blood cell activation
The anti-TNF-α antibody infliximab indirectly regulates PECAM-1 gene expression in two models of in vitro blood cell activation
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DOI：
10.1038/labinvest.2011.160
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发表时间：
2012-02-01
影响因子：
5
通讯作者：
Ramadori, Giuliano
中科院分区：
文献类型：
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作者：
Moriconi, Federico;Malik, Ihtzaz Ahmed;Ramadori, Giuliano
慢性炎症性肠病可以成功地治疗急性期介质TNF-α的抗体。炎症细胞从血液中激活和外渗到“应激”组织部位的过程受细胞因子和趋化因子的控制，这些细胞因子和趋化因子吸引白细胞，并受粘附分子的控制，这些粘附分子介导白细胞附着并向受影响的细胞迁移。粘附分子的基因表达的变化发生在这些细胞在附着前已经很少研究。研究了植物血凝素（PHA）和脂多糖（LPS）处理的人外周血白细胞（PBL）、粒细胞和人单核细胞系U-937中PECAM-1、ICAM-1和血管细胞粘附分子-1（VCAM-1）基因表达的变化。在存在或不存在英夫利昔单抗的情况下用PHA或LPS处理细胞，并与TNF-α、IFN-γ和/或转化生长因子β（TGF-β）孵育，并如上处理。通过PHA或LPS处理激活PBL触发ICAM-1、VCAM-1基因表达的急剧上调和PECAM-1基因表达的时间依赖性下调，从实验开始达到最小4 h。抗TNF-α抗体英夫利西单抗通过中和TNF-α和IFN-γ的产生，完全逆转了PECAM-1 mRNA的下调以及ICAM-1和VCAM-1的上调。用抗PECAM-1和ICAM-1的抗体对PBL细胞离心涂片进行免疫染色证实了RT-PCR和western blot结果。IFN-γ或TNF-α处理PBLs下调PECAM-1，同时上调ICAM-1和VCAM-1基因表达，而TGF-β上调PECAM-1，下调ICAM-1和VCAM-1基因表达，抵消TNF-α或IFN-γ的作用。通过TNF-α或IFN-γ处理，在人U937细胞和粒细胞培养物中获得了类似的结果。总之，这些结果表明，英夫利西单抗，阻断TNF-α和IFN-γ的产生，发挥其抗炎作用，通过抑制PECAM-1基因表达的下调和上调ICAM-1和VCAM-1的表达在外周血白细胞。这些结果还表明，TGF-β可能因此作为抗炎剂具有治疗重要性。实验室调查（2012）92，166-177; doi：10.1038/labinvest.2011.160;在线发表2011年10月31日
Chronic inflammatory bowel diseases can be successfully treated with antibodies against the acute phase mediator TNF-alpha. The process of activation and of extravasation of inflammatory cells from the blood into the 'stressed' tissue site is controlled by cytokines and chemokines, which attract leukocytes and by adhesion molecules, which mediate their attachment and transmigration toward the affected cell(s). The changes in the gene expression of adhesion molecules taking place in those cells before attachment have been less investigated. Changes of PECAM-1, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) gene expression were studied in phytohaemagglutinin (PHA)- and lipolysaccharide (LPS)-treated human peripheral blood leukocytes (PBLs), granulocytes and the human monocyte cell line U-937. Cells were treated either with PHA or with LPS in the presence or absence of infliximab and incubated with TNF-alpha, IFN-gamma and/or transforming growth factor beta (TGF-beta) and treated as above. Activation of PBLs by PHA or LPS treatment triggered a sharp upregulation of ICAM-1, VCAM-1 gene expression and a time-dependent downregulation of PECAM-1 gene expression reaching a minimum 4 h from start of the experiment. The anti-TNF-alpha antibody infliximab, by neutralizing TNF-alpha and IFN-gamma production, completely reversed PECAM-1 mRNA downregulation and ICAM-1 and VCAM-1 upregulation. Immunostaining of PBLs cytospins with antibodies against PECAM-1 and ICAM-1 confirmed RT-PCR and western blot results. PBLs IFN-gamma or TNF-alpha treatment downregulated PECAM-1 in parallel with the upregulation of ICAM-1 and VCAM-1 gene expression, whereas TGF-beta upregulated PECAM-1- and downregulated ICAM-1 and VCAM-1 gene expression counteracting the effect of TNF-alpha or IFN-gamma. Similar results were obtained in human U937 cells and in granulocyte cultures by TNF-alpha or IFN-gamma treatment. Taken together, these results suggest that infliximab, blocking TNF-alpha and IFN-gamma production, exerts its anti-inflammatory effect through inhibiting downregulation of PECAM-1 gene expression and upregulation of ICAM-1 and VCAM-1 expression in leukocytes of the peripheral blood. These results also suggest that TGF-beta may thus be of therapeutic importance as an anti-inflammatory agent. Laboratory Investigation (2012) 92, 166-177; doi:10.1038/labinvest.2011.160; published online 31 October 2011