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提出了脂筏的存在，使细胞质膜内可以进行有效的信号转导。据报道，甲基-环糊精(M-β-环糊精，M-β-CD)降低脂筏中的胆固醇含量干扰了信号转导，而内糖神经酰胺酶II加激活剂II(Egpa)处理选择性地去除脂筏中的碳水化合物，通过糖基磷脂酰肌醇(GPI)锚定蛋白的交联，削弱了酪氨酸激酶Src家族的激活。基于这些发现，本研究确定了脂筏上存在的胆固醇和gpi锚定蛋白的作用，以阐明phe-b-pst-b-phEMA ABA型嵌段共聚物(HSB)抑制淋巴细胞激活的机制，该嵌段共聚物具有纳米结构表面，片层宽度为16 nm，由用于…的亲水性聚甲基丙烯酸羟乙酯(PhEMA)组成。更多的是A链段和形成B链段的疏水聚苯乙烯(PSt)。以PSt和P(HEMA-co-St)无规共聚物(HSR)为对照。用微球柱法进行了测定淋巴细胞与材料表面相互作用效率的实验。将淋巴细胞分为三组：未处理组、M-βCD处理组和EGPA处理组。用电子显微镜分析材料表面淋巴细胞在室温下1小时的黏附情况。贴附在PST和HSR表面的未经处理的淋巴细胞呈现弥漫性坏死，而贴附在纳米结构表面的淋巴细胞保持了与对照淋巴细胞相似的形态和细胞构筑。在MβCD和EGPA处理的淋巴细胞中，所有附着在PST、HSR和纳米结构域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构筑。从以上这些结果可以推测，与PST和HSR表面相比，HSB的纳米结构表面允许维持脂筏的结构完整性，并且在纳米结构表面的淋巴细胞黏附位置没有包含GPI锚定蛋白的脂筏聚集的情况下，酪氨酸激酶Src家族的激活被抑制。较少

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