Localization of submembranous cations to the leading end of human neutrophils during chemotaxis.
Localization of submembranous cations to the leading end of human neutrophils during chemotaxis.
复制标题
DOI：
10.1083/jcb.82.2.369
复制
发表时间：
1979-08
期刊：
影响因子：
--
通讯作者：
Gallin JI
中科院分区：
文献类型：
--
作者：
Cramer EB;Gallin JI
焦锑酸钾被用来定位网站的结合阳离子在人类中性粒细胞的条件下的随机迁移，刺激随机迁移（趋化作用），定向迁移（趋化性）。将细胞置于标准室中，其中0.45 μ m滤膜将细胞与刺激物（缓冲液、大肠杆菌内毒素激活血清或合成趋化肽N-甲酰基-Met-Leu-Phe）分离。小孔过滤器允许伪足形成，但阻碍细胞通过过滤器迁移。在所有条件下检查的细胞在一些颗粒中具有锑酸盐的电子致密沉淀。然而，锑酸盐沉积物在随机迁移过程中定位于细胞核的浓缩染色质中，并在很大程度上与化动和趋化过程中未浓缩的核染色质相关。在趋化作用的条件下，锑酸盐沉淀物出现在中性粒细胞质膜的细胞质侧，而在趋化作用的条件下，细胞膜下的阳离子沉积物被定位于伪足，伪足被定向朝向趋化物。除了内毒素活化血清外，引起中性粒细胞趋化性的N-甲酰-Met-Leu-Phe浓度（10（-8）M）也引起细胞前端细胞膜下的阳离子沉积，而不管孵育培养基中是否存在白蛋白。然而，在较高浓度的合成肽（10（-5）M）（其引起颗粒释放且不具有趋化性）下，未观察到膜下阳离子沉积。EDTA（10 mM）和EGTA（10 mM）去除核，颗粒，和膜下的阳离子沉积物从中性粒细胞的趋化性条件下检查。锑酸盐沉积物的X射线微探针分析显示可能存在钙，但没有检测到钠或镁。这些数据表明，趋化因子诱导的阳离子，最有可能的Ca++，定位于细胞的前缘暴露于梯度的趋化因子的膜下沉积。
Potassium pyroantimonate was used to localize sites of bound cations in human neutrophils under conditions of random migration, stimulated random migration (chemokinesis), and directed migration (chemotaxis). The cells were placed in a standard chamber in which 0.45-micron micropore filters separated the cells from the stimulus (buffer, Escherichia coli endotoxin-activated serum or the synthetic chemotactic peptide N-formyl-Met-Leu-Phe). The small pore filters permitted pseudopod formation but impeded cell imgration through the filter. Cells examined under all conditions had electron-dense precipitates of antimonate salts in some granules. However, antimonate deposits were localized in the condensed chromatin of the nucleus during random migration and associated to a large extent with the uncondensed nuclear chromatin during chemokinesis and chemotaxis. Under conditions of chemokinesis deposition of antimonate procipitates appeared on the cytoplasmic side of the plasma membrane of neutrophils whereas under conditions of chemotaxis cation deposits beneath the cell membrane were localized to the pseudopods which were directed toward the chemoattractant. In addition to endotoxin-activated serum, concentrations of N-formyl-Met-Leu-Phe which caused neutrophil chemotaxis (10(-8) M) also caused cation deposition beneath the cell membrane at the leading end of the cell regardless of whether albumin was present in the incubation media. However, with higher concentrations of the synthetic peptide (10(-5) M) which caused granule release and were not chemotactic, submembranous cation deposition was not seen. EDTA (10 mM) and EGTA (10 mM) removed nuclear, granular, and submembranous cation deposits from neutrophils examined under conditions of chemotaxis. X-ray microprobe analysis of antimonate deposits revealed the possible presence of calcium but did not detect sodium or magnesium. The data indicate that chemotactic factors induce submembranous deposition of cations, most likely Ca++, which localize to the leading edge of cells exposed to a gradient of chemoattractant.