Gregorio C C, Black J D, Repasky E A
Department of Molecular Immunology, Roswell Park Cancer Institute, Buffalo, New York 14263.
Blood Cells. 1993;19(2):361-71; discussion 371-3.
Our studies on the lymphocyte cytoskeleton have revealed a significant heterogeneity in the subcellular distribution of lymphocyte spectrin in vivo. Two model systems have been characterized in which this protein exhibits dynamic properties in response to activation signals. In this study, we have investigated the role of calcium in the activation-induced reorganization of spectrin in one of these systems, the DO-11.10 T cell hybridoma. DO-11.10 cells, as well as several other in vitro T cell models, can homogeneously and constitutively express a distinct cytoplasmic aggregate of spectrin that is rapidly fragmented upon activation. The reversible dissipation of the aggregate of spectrin is accompanied by an increase in the levels of spectrin diffusely distributed throughout the cytoplasm and at the plasma membrane. Pretreatment of cells with calcium-free medium, or with medium containing ethyleneglycol-bis-(beta-aminoethyl ether)N,N'-tetraacetic acid (EGTA) or verapamil, significantly blocked the reorganization of spectrin induced by Concanavalin A or the calcium ionophore A23187, and also prevented the release of IL-2 from these cells. Further, immunofluorescent and ultrastructural analyses revealed abnormalities in the organization of spectrin induced by these treatments. These findings are discussed in light of our other studies, indicating a role for spectrin in early events associated with activation of T lymphocytes in vivo and in vitro.
我们对淋巴细胞细胞骨架的研究揭示了体内淋巴细胞血影蛋白亚细胞分布存在显著的异质性。已对两种模型系统进行了表征，在其中该蛋白会响应激活信号而展现出动态特性。在本研究中，我们研究了钙在其中一种系统即DO-11.10 T细胞杂交瘤中激活诱导的血影蛋白重组中的作用。DO-11.10细胞以及其他几种体外T细胞模型能够均匀且组成性地表达一种独特的血影蛋白细胞质聚集体，该聚集体在激活时会迅速碎片化。血影蛋白聚集体的可逆消散伴随着在整个细胞质和质膜中弥散分布的血影蛋白水平的增加。用无钙培养基、或含有乙二醇双（β-氨基乙基醚）N，N'-四乙酸（EGTA）或维拉帕米的培养基对细胞进行预处理，可显著阻断伴刀豆球蛋白A或钙离子载体A23187诱导的血影蛋白重组，还可阻止这些细胞释放白细胞介素-2。此外，免疫荧光和超微结构分析揭示了这些处理诱导的血影蛋白组织异常。结合我们的其他研究对这些发现进行了讨论，表明血影蛋白在体内和体外与T淋巴细胞激活相关的早期事件中发挥作用。
