Stephen F D, Yokota S J, Repasky E A
Department of Molecular Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263.
Cell Biophys. 1990 Dec;17(3):269-82. doi: 10.1007/BF02990722.
Previous studies have shown that cis unsaturated free fatty acids (uFFAs) are able to cause alterations in the normal distribution pattern of certain cytoskeletal proteins in lymphocytes, including tubulin, actin, alpha-actinin, and myosin. The cytoskeletal protein spectrin naturally possesses a marked heterogeneity of distribution among resting T and B lymphocytes isolated from all murine lymphoid organs. In some cells, spectrin is observed in a ring-like staining pattern at the periphery of the cell, reflecting a likely association with the cell membrane; in other cells, spectrin is found within the cytoplasm as a large single aggregate or in several smaller aggregates. Addition of uFFA to freshly isolated murine lymphocytes causes disruption in the latter pattern of spectrin organization. Following short-term incubation (15 min) of tissue-derived lymphocytes (from spleen, thymus, and lymph node) and 1 microgram/mL uFFA (oleic [18:1 cis], linoleic [18:2 cis, cis], arachidonic [20:4], or elaidic [18:1 trans] acid) there is a loss of cytoplasmic aggregates of spectrin and a concomitant increase in cells in which spectrin is diffusely distributed. This effect is not seen when two saturated FFAs (sFFAs) were used. When using DO11.10 cells, a T-cell hybridoma in which nearly all cells constitutively express a cytoplasmic aggregate of spectrin, a similar effect was observed, but greater concentrations (10-20 micrograms/mL) of FFA were needed to obtain the same effect. Addition of calcium to the incubation buffer substantially blocks spectrin reorganization. In several disease states, serum levels of FFA are observed to be excessively high; our data support the hypothesis that cytoskeletal reorganization in lymphocytes may be related to the altered immune function frequently observed in these conditions.
先前的研究表明，顺式不饱和游离脂肪酸（uFFAs）能够导致淋巴细胞中某些细胞骨架蛋白的正常分布模式发生改变，这些蛋白包括微管蛋白、肌动蛋白、α-辅肌动蛋白和肌球蛋白。细胞骨架蛋白血影蛋白在从所有小鼠淋巴器官分离出的静息T淋巴细胞和B淋巴细胞中自然呈现出明显的分布异质性。在一些细胞中，血影蛋白以环状染色模式出现在细胞周边，这可能反映了其与细胞膜的关联；在其他细胞中，血影蛋白则以大的单个聚集体或几个较小聚集体的形式存在于细胞质中。向新鲜分离的小鼠淋巴细胞中添加uFFA会破坏血影蛋白的后一种组织模式。将组织来源的淋巴细胞（来自脾脏、胸腺和淋巴结）与1微克/毫升的uFFA（油酸[顺式18:1]、亚油酸[顺式，顺式18:2]花生四烯酸[20:4]或反油酸[反式18:1]）短期孵育（15分钟）后，血影蛋白的细胞质聚集体减少，同时血影蛋白呈弥漫性分布的细胞数量相应增加。当使用两种饱和脂肪酸（sFFAs）时，未观察到这种效应。使用DO11.10细胞（一种T细胞杂交瘤，其中几乎所有细胞都组成性表达血影蛋白的细胞质聚集体）时，也观察到了类似的效应，但需要更高浓度（10 - 20微克/毫升）的脂肪酸才能获得相同的效果。向孵育缓冲液中添加钙可显著阻止血影蛋白的重组。在几种疾病状态下，观察到血清中脂肪酸水平过高；我们的数据支持这样一种假说，即淋巴细胞中的细胞骨架重组可能与这些情况下经常观察到的免疫功能改变有关。
