Identification of an astrocyte cell population from human brain that expresses perforin, a cytotoxic protein implicated in immune defense.
Identification of an astrocyte cell population from human brain that expresses perforin, a cytotoxic protein implicated in immune defense.
复制标题
DOI：
10.1084/jem.187.4.451
复制
发表时间：
1998-02-16
期刊：
影响因子：
--
通讯作者：
Morgan B
中科院分区：
文献类型：
--
作者：
Gasque P;Jones J;Singhrao SK;Morgan B
大脑是一个独立于外周免疫系统的免疫器官。然而，已有研究表明，常驻细胞，特别是星形胶质细胞和小胶质细胞，可以表达许多先天免疫分子，提供产生局部抗病原系统的能力。穿孔素是一种细胞溶解蛋白，存在于细胞毒性T淋巴细胞和自然杀伤细胞颗粒中。在造血谱系以外的其他细胞中的表达还没有被描述。我们在此报告培养中的胎儿星形胶质细胞(第2-15代)、星形细胞瘤和成人星形胶质细胞表达穿孔素。采用逆转录聚合酶链式反应和Southern印迹杂交技术，对所有基因进行克隆和测序。人胎儿星形胶质细胞穿孔素∼序列与已报道的从T细胞克隆的穿孔素全长同源性为100%。用单抗和多克隆抗穿孔素肽抗体进行Western印迹分析，发现人胎儿星形胶质细胞和大鼠自然杀伤细胞裂解物(n=4)均含有65kD的蛋白质。免疫染色、FACS®、共聚焦和电子显微镜分析表明，在胎脑培养中，40-50%的胶质纤维酸性蛋白阳性细胞表达穿孔素(n=11)。穿孔素不定位于星形胶质细胞中的颗粒，但存在于细胞质中，可能与内质网有关。在正常成人脑组织中没有检测到穿孔素，但在多发性硬化症和神经退行性变的脑组织中，穿孔素存在于炎症区域(白质和灰质)及其周围。穿孔素阳性细胞为反应性星形胶质细胞。这些发现表明，穿孔素的表达并不是淋巴细胞所特有的，并表明星形胶质细胞亚群产生的穿孔素在脑部炎症中发挥了作用。
The brain is an immunoprivileged organ isolated from the peripheral immune system. However, it has been shown that resident cells, notably astrocytes and microglia, can express numerous innate immune molecules, providing the capacity to generate a local antipathogen system. Perforin is a cytolytic protein present in the granules of cytotoxic T lymphocytes and natural killer cells. Expression in cells other than those of the hemopoetic lineage has not been described. We report here that fetal astrocytes in culture (passages 2 to 15), astrocytoma, and adult astrocytes expressed perforin. Reverse transcriptase polymerase chain reaction followed by Southern blot was carried out using multiple specific primers and all cDNAs were cloned and sequenced. Human fetal astrocyte perforin cDNA sequence was ∼100% identical to the reported perforin cDNA cloned from T cells. Western blot analysis using monoclonal and polyclonal antiperforin peptide antibodies revealed a protein of 65 kD in both human fetal astrocyte and rat natural killer cell lysates (n = 4). Immunostaining followed by FACS® and confocal and electron microscopy analysis revealed that perforin was expressed by 40–50% of glial fibrillary acidic protein positive cells present in the fetal brain culture (n = 11). Perforin was not localized to granules in astrocytes but was present throughout the cytoplasm, probably in association with the endoplasmic reticulum. Perforin was not detected in normal adult brain tissue but was present in and around areas of inflammation (white and grey matter) in multiple sclerosis and neurodegenerative brains. Perforin-positive cells were identified as reactive astrocytes. These findings demonstrate that perforin expression is not unique to lymphoid cells and suggest that perforin produced by a subpopulation of astrocytes plays a role in inflammation in the brain.