Analysis of the mechanism of regulation of lipid rafts within the lymphocyte plasma membrane by the lamellar-shaped nanodomain-structured surface

最近，Simons K和Ikonen e提出在细胞质膜内存在脂筏，可以进行有效的信号转导。据报道，用甲基β-环糊精（m -β cd）处理脂筏中胆固醇含量的降低会干扰信号转导。通过糖基磷脂酰肌醇（GPI）锚定蛋白的交联处理，内糖神经酰胺酶II和激活剂II（EGPA）选择性地从脂筏的糖鞘脂中去除碳水化合物，从而损害了酪氨酸激酶Src家族的激活。基于这些发现，本研究旨在确定胆固醇和gpi锚定蛋白在脂筏上的作用，以阐明PHEMA-b-PSt-b-PHEMA ABA型嵌段共聚物（HSB）抑制淋巴细胞活化的机制，该共聚物具有纳米结构域结构表面，片层宽度为16nm。由亲水聚甲基丙烯酸2-羟乙基酯（PHEMA）组成，形成A段，疏水聚苯乙烯（PSt）形成B段。以PSt和P（HEMA-co-St）无规共聚物（HSR）为对照。用微球柱法测定了淋巴细胞与材料表面的相互作用效率。淋巴细胞分为三组；未处理、m β cd处理和egpa处理。电镜观察室温下1小时淋巴细胞对材料表面的粘附情况。未处理的淋巴细胞粘附在PSt和HSR表面呈弥漫性坏死，而粘附在纳米结构表面的淋巴细胞形状和细胞结构保持不变，与对照淋巴细胞相似。在m β cd和egpa处理的淋巴细胞中，所有粘附在PSt、HSR和纳米结构表面的淋巴细胞都保持了与对照淋巴细胞相似的形状和细胞结构。根据上述结果，我们推测，与PSt和HSR表面相比，HSB的纳米结构域表面可以维持脂筏的结构完整性，并且Src家族酪氨酸激酶的激活被抑制，而不会在纳米结构域表面淋巴细胞粘附部位积累含有gpi锚定蛋白的脂筏。少

Recently, the presence of lipid rafts allowing efficient signal transduction within the plasma membrane of the cell was proposed by Simons K and Ikonen E. It was reported that a decrease in the cholesterol content of lipid rafts by treatment with methyl-β-cyclodextrin(MβCD) disturbed signal transduction, and that selective removal of carbohydrates from the glycosphingolipid of lipid rafts by treatment with endoglycoceramidase II plus activator II(EGPA) impaired activation of the Src family of tyrosine kinases through crosslinking of glycosylphosphatidylinositol(GPI)-anchored proteins. Based on these findings, this study was conducted to determine the role of the cholesterol and GPI-anchored proteins present on lipid rafts, in order to clarify the mechanism of inhibition of lymphocyte activation on PHEMA-b-PSt-b-PHEMA ABA type block copolymer(HSB) having a nanodomain-structured surface with a lamellar width of 16nm, consisting of hydrophilic poly (2-hydroxyethyl methacrylate)(PHEMA) for … More ming the A segment and hydrophobic polystyrene(PSt) forming the B segment. PSt and P(HEMA-co-St) random copolymers(HSR) were used as controls. An experiment of to determine the efficiency of interaction of lymphocytes with material surfaces was carried out by the microsphere column method. The lymphocytes were divided into three groups ; non-treated, MβCD-treated and EGPA-treated. The adherence of the lymphocytes to the material surfaces at room temperature for one hour was analyzed by electron microscopy. The non-treated lymphocytes adhering to the PSt and HSR surfaces showed spreading necrosis, whereas the lymphocytes adhering to the nanodomain-structured surfaces showed maintained shape and cytoarchitecture, similar to control lymphocytes. In the case of MβCD-and EGPA-treated lymphocytes, all the lymphocytes adhering to the PSt, HSR and nanodomain-structured surfaces exhibited maintained shape and cytoarchitecture, similar to control lymphocytes. From the above these results, it is surmised that the nanodomain-structured surface of HSB, in contrast to the PSt and HSR surfaces, allows maintenance of the structural integrity of the lipid rafts, and that activation of the Src family of tyrosine kinases is inhibited without an accumulation of lipid rafts containing the GPI-anchored proteins at the sites of lymphocyte adhesion on the nanodomain-structured surface. Less