Human plasma fibronectin mediates adhesion of U937 cells by RGD and CS1
Human plasma fibronectin mediates adhesion of U937 cells by RGD and CS1
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DOI：
10.1023/a:1008878012268
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发表时间：
1998-03-01
影响因子：
4
通讯作者：
Okubo, T
中科院分区：
文献类型：
--
作者：
Katoh, K;Mohri, H;Okubo, T
纤连蛋白以剂量依赖性方式特异性结合 U937 细胞（单核细胞系）。 RGD序列的特异性受体已被鉴定为α(5)β(1)和α(IIb)β(2)，CS1的特异性受体已被定义为α(4)β(1)。 RGDS、CS1 肽和两种肽一起对这种粘附表现出类似的抑制活性，而 C 端肝素结合结构域的 29-kD 分散酶消化片段却没有。因此，纤连蛋白与U937细胞的粘附主要由细胞结合域中的RGDS和可变剪接区域中的CS1介导。使用单克隆抗体的流式细胞术显示α(3)β(1)、α(4)β(1)和α(5)β(1)的表达，而不是α(2)β(1)的表达。 U937 细胞对纤连蛋白包被的孔具有特异性粘附，并且可被抗 α(4)β(1) 和抗 α(5)β(1) 单克隆抗体抑制。抗α(5)β(1)抗体的IC50几乎比抗α(4)β(1)抗体的值低一个对数。这些结果表明，U937细胞上纤连蛋白的RGDS和CS1序列与α(5)β(1)和α(4)β(1)的相互作用仅仅是U937细胞与纤连蛋白粘附所必需的。这些结果可以提供进一步的信息来了解肿瘤细胞粘附和动脉粥样硬化形成的机制。
Fibronectin specifically binds to U937 cells (monocytic cell line) in a dose-dependent manner. The specific receptors for the RGD sequence have been identified as alpha(5)beta(1) and alpha(IIb)beta(2), and that for CS1 has been defined as alpha(4)beta(1). RGDS, CS1 peptide, and two peptides together showed similar inhibitory activities on this adhesion, while the 29-kD dispase-digested fragment of the C-terminal heparin-binding domain did not. Thus, the adhesion of fibronectin to U937 cells is mainly mediated by RGDS in the cell-binding domain and CS1 in the alternatively spliced region. Flow cytometry using monoclonal antibodies revealed expressions of alpha(3)beta(1), alpha(4)beta(1), and alpha(5)beta(1), and not expression of alpha(2)beta(1). Adhesion of U937 cells to fibronectin-coated wells is specific and is inhibited by anti-alpha(4)beta(1), and anti-alpha(5)beta(1) monoclonal antibodies. The IC50 for anti-alpha(5)beta(1) antibody was almost a log lower than the value for anti-alpha(4)beta(1) antibody. These results demonstrated that interactions of RGDS and CS1 sequence of fibronectin with alpha(5)beta(1) and alpha(4)beta(1) on U937 cells mere required for the adhesion of U937 cells to fibronectin. These results may provide further information to understand the mechanism(s) of tumor cell adhesion and atherogenesis.