Functional channel formation associated with cytotoxic T-cell granules.
Functional channel formation associated with cytotoxic T-cell granules.
复制标题
与细胞毒性 T 细胞颗粒相关的功能通道形成。
DOI：
10.1073/pnas.83.1.150
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发表时间：
1986
影响因子：
11.1
通讯作者：
Cohn,ZA
中科院分区：
文献类型：
--
作者：
Young,JD;Nathan,CF;Podack,ER;Palladino,MA;Cohn,ZA
利用Percoll梯度亚细胞分离富集细胞毒性t淋巴细胞系A2、A11和R8的淋巴细胞颗粒。在Ca2+的存在下，颗粒富集的组分显示出有效的溶血活性。分离颗粒诱导J774巨噬细胞样细胞Ca2+依赖性膜快速去极化。当在平面双分子层中测试时，颗粒在0.1 M NaCl中诱导形成1-6 nS大电导阶的Ca2+依赖功能离子通道。颗粒诱导的通道通过增加跨膜电位来抵抗关闭，只有少数通道在大于70 mV的电压下才会按照泊松过程转变为关闭状态。这些通道表现出较差的离子选择性，对所有单价和二价离子（K+, Na+, Li+, Cl-, Ca2+, Mg2+, Zn2+, Ba2+）都具有渗透性。可溶性颗粒蛋白在Ca2+存在下，在37℃下培养48小时，超微结构检查显示150-200 A的环状结构。结构和功能通道的形成可能与细胞毒性T淋巴细胞诱导的细胞溶解有关。
Lymphocyte granules from cytotoxic T-lymphocyte lines A2, A11, and R8 were enriched by subcellular fractionation using a Percoll gradient. Granule-enriched fractions showed potent hemolytic activity in the presence of Ca2+. Isolated granules induced rapid Ca2+-dependent membrane depolarization of J774 macrophage-like cells. When tested in planar bilayers, granules induced the formation of Ca2+-dependent functional ion channels of large conductance steps of 1-6 nS in 0.1 M NaCl. Granule-induced channels were resistant to closing by an increase in transmembrane potential, with few channels shifting to the closed state only at voltages of greater than 70 mV, following a Poisson process. These channels showed poor ion selectivity and were permeable to all monovalent and divalent ions (K+, Na+, Li+, Cl-, Ca2+, Mg2+, Zn2+, Ba2+). Ultrastructural examination of soluble granule proteins incubated for 48 hr at 37 degrees C in the presence of Ca2+ revealed ring-like structures of 150-200 A. Structural and functional channel formation may be involved in cytolysis induced by cytotoxic T lymphocytes.