The activation dependent adhesion of macrophages to laminin involves cytoskeletal anchoring and phosphorylation of the alpha 6 beta 1 integrin.
The activation dependent adhesion of macrophages to laminin involves cytoskeletal anchoring and phosphorylation of the alpha 6 beta 1 integrin.
复制标题
巨噬细胞对层粘连蛋白的激活依赖性粘附涉及α6β1整合素的细胞骨架锚定和磷酸化。
DOI：
10.1083/jcb.110.6.2167
复制
发表时间：
1990-06
期刊：
影响因子：
--
通讯作者：
Mercurio AM
中科院分区：
文献类型：
--
作者：
Shaw LM;Messier JM;Mercurio AM
巨噬细胞需要用PMA（Mercurio，A. M.，和L. M.肖1988. 107：1873-1880）或干扰素-γ（Shaw，L. M.，和A. M.莫库里奥1989. J. Exp. 169：303-308）粘附于层粘连蛋白基质。在本研究中，我们确定了整合素层粘连蛋白受体的巨噬细胞和特征的细胞变化，发生在响应PMA激活，促进层粘连蛋白粘附。识别整联蛋白α 6亚基的单克隆抗体（GoH 3）（Sonnenberg，A.，H. Janssen，F. Hogervorst，J.卡拉法特，和J. Hilgers. 1987. J.Biol.Chem.262：10376-10383）特异性地抑制对层粘连蛋白涂覆的表面的粘附。该抗体从125 I表面标记的巨噬细胞中沉淀α 6 β 1异二聚体（Mr 130/110 kD）。PMA激活后，细胞表面放射性标记受体的数量没有增加。因此，层粘连蛋白粘附的诱导不能归因于α 6 β 1的从头或增加的表面表达。通过最初去除巨噬细胞的Triton X-100可溶性部分，然后破坏剩余的细胞骨架框架，我们观察到细胞表面上75%的α 6 β 1异源二聚体锚定在巨噬细胞中的细胞骨架上，巨噬细胞响应于PMA而粘附在层粘连蛋白基质上。在粘附于纤连蛋白或组织培养塑料的巨噬细胞中未观察到该受体的显著细胞骨架锚定，在非粘附细胞中也未观察到。PMA还诱导α 6亚基胞质结构域的磷酸化，但不诱导β 1亚基的磷酸化。磷酸化的α 6仅在铺在层粘连蛋白基质上的巨噬细胞中定位于细胞骨架部分。总之，我们的研究结果支持一种机制，涉及特定的和动态的基质整合素细胞骨架的相互作用，可能是促进整合素磷酸化的巨噬细胞粘附层粘连蛋白的调节。
Macrophages require activation with either PMA (Mercurio, A. M., and L. M. Shaw. 1988. J. Cell Biol. 107:1873-1880) or interferon-gamma (Shaw, L. M., and A. M. Mercurio. 1989. J. Exp. Med. 169:303-308) to adhere to a laminin substratum. In the present study, we identified an integrin laminin receptor on macrophages and characterized cellular changes that occur in response to PMA activation that facilitate laminin adhesion. A monoclonal antibody (GoH3) that recognizes the integrin alpha 6 subunit (Sonnenberg, A., H. Janssen, F. Hogervorst, J. Calafat, and J. Hilgers. 1987. J. Biol. Chem. 262:10376-10383) specifically inhibited adhesion to laminin-coated surfaces. This antibody precipitated an alpha 6 beta 1 heterodimer (Mr 130/110 kD) from 125I surface-labeled macrophages. The amount of radiolabeled receptor on the cell surface did not increase after PMA activation. Thus, the induction of laminin adhesion cannot be attributed to de novo or increased surface expression of alpha 6 beta 1. By initially removing the Triton X-100-soluble fraction of macrophages and then disrupting the remaining cytoskeletal framework, we observed that 75% of the alpha 6 beta 1 heterodimer on the cell surface is anchored to the cytoskeleton in macrophages that had adhered to a laminin substratum in response to PMA. Significant cytoskeletal anchoring of this receptor was not observed in macrophages that had adhered to fibronectin or tissue culture plastic, nor was it seen in nonadherent cells. PMA also induced phosphorylation of the cytoplasmic domain of the alpha 6 subunit, but not the beta 1 subunit. Phosphorylated alpha 6 was localized to the cytoskeletal fraction only in macrophages plated on a laminin substratum. In summary, our results support a mechanism for the regulation of macrophage adhesion to laminin that involves specific and dynamic matrix integrin-cytoskeletal interactions that may be facilitated by integrin phosphorylation.