Two modes of lytic granule fusion during degranulation by natural killer cells.
Two modes of lytic granule fusion during degranulation by natural killer cells.
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DOI：
10.1038/icb.2010.167
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发表时间：
2011-08
影响因子：
4
通讯作者：
Long, Eric O.
中科院分区：
文献类型：
--
作者：
Liu, Dongfang;Martina, Jose A.;Wu, Xufeng S.;Hammer, John A., III;Long, Eric O.
细胞毒性淋巴细胞（包括 T 细胞和自然杀伤 (NK) 细胞）中的裂解颗粒是分泌性溶酶体，在与质膜 (PM) 融合后释放其内容物，这一过程称为脱颗粒。尽管囊泡胞吐作用已在内分泌和神经元细胞中得到广泛研究，但对细胞毒性淋巴细胞中溶解颗粒的融合知之甚少。在这里，我们使用全内反射荧光显微镜检查用佛波酯和离子霉素刺激的 NK 细胞系 NKL 以及由生理受体-配体相互作用激活的原代 NK 细胞中用荧光标记的 Fas 配体 (FasL) 标记的裂解颗粒。观察到两种融合模式：完全融合，其特征是 PM 时颗粒含量的损失和 FasL 的快速扩散；和不完全融合，其特征是融合孔短暂打开并且FasL保留在融合位点。 pH 敏感的绿色荧光蛋白 (pHluorin) 融合到 FasL 的腔域，用于以 30 毫秒的时间分辨率可视化融合孔的打开。在不完全融合时，pHluorin 发射持续了几秒钟，没有明显的扩散。因此，我们得出结论，NK细胞中的裂解颗粒与PM发生完全和不完全融合，并提出不完全融合可能促进细胞毒性效应分子释放后裂解颗粒膜的有效回收。
Lytic granules in cytotoxic lymphocytes, which include T cells and natural killer (NK) cells, are secretory lysosomes that release their content upon fusion with the plasma membrane (PM), a process known as degranulation. Although vesicle exocytosis has been extensively studied in endocrine and neuronal cells, much less is known about the fusion of lytic granules in cytotoxic lymphocytes. Here, we used total internal reflection fluorescence microscopy to examine lytic granules labeled with fluorescently tagged Fas ligand (FasL) in the NK cell line NKL stimulated with phorbol ester and ionomycin and in primary NK cells activated by physiological receptor–ligand interactions. Two fusion modes were observed: complete fusion, characterized by loss of granule content and rapid diffusion of FasL at the PM; and incomplete fusion, characterized by transient fusion pore opening and retention of FasL at the fusion site. The pH-sensitive green fluorescence protein (pHluorin) fused to the lumenal domain of FasL was used to visualize fusion pore opening with a time resolution of 30 ms. Upon incomplete fusion, pHluorin emission lasted several seconds in the absence of noticeable diffusion. Thus, we conclude that lytic granules in NK cells undergo both complete and incomplete fusion with the PM, and propose that incomplete fusion may promote efficient recycling of lytic granule membrane after the release of cytotoxic effector molecules.
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DOI：
10.1083/jcb.57.2.499
发表时间：
1973-05
期刊：
The Journal of cell biology
影响因子：
--
作者：
Ceccarelli B;Hurlbut WP;Mauro A
通讯作者：
Mauro A
影响因子：
7.8
作者：
HEUSER, JE;REESE, TS
通讯作者：
REESE, TS
影响因子：
15.9
作者：
Cote, Marjorie;Menager, Mickael M.;de Saint Basile, Genevieve
通讯作者：
de Saint Basile, Genevieve
影响因子：
20.3
作者：
Bryceson, Yenan T.;Rudd, Eva;Ljunggren, Hans-Gustaf
通讯作者：
Ljunggren, Hans-Gustaf
影响因子：
64.5
作者：
Jaiswal JK;Rivera VM;Simon SM
通讯作者：
Simon SM