STIMULUS-DEPENDENT SECRETION OF PLASMA-PROTEINS FROM HUMAN NEUTROPHILS
STIMULUS-DEPENDENT SECRETION OF PLASMA-PROTEINS FROM HUMAN NEUTROPHILS
复制标题
DOI：
10.1172/jci115860
复制
发表时间：
1992-07-01
影响因子：
15.9
通讯作者：
JOHNSEN, AH
中科院分区：
文献类型：
--
作者：
BORREGAARD, N;KJELDSEN, L;JOHNSEN, AH
在寻找中性粒细胞分泌囊泡释放的基质蛋白时，在趋化多肽FMLP刺激的中性粒细胞胞外介质中发现了一种重要的67-kD蛋白。该蛋白被提纯到明显的同质性，并进行了部分测序。前32个氨基末端氨基酸的序列与白蛋白的序列相同。在与[C-14]亮氨酸孵育过程中，骨髓细胞不能检测到人白蛋白的mRNA，也没有白蛋白的生物合成标记。对单个细胞的免疫荧光研究表明，固定的渗透性中性粒细胞中存在细胞内白蛋白。免疫金银染色的冰冻切片光镜下可见细胞质“颗粒”中的白蛋白。免疫电子显微镜观察其形态为不同形状和大小的囊泡。对未受刺激的中性粒细胞的亚细胞分级研究表明，白蛋白存在于含有分泌小泡的低密度伽马前区和伽马区，但没有特殊颗粒和嗜天青颗粒。在炎性介质激活中性粒细胞时，白蛋白很容易从这些结构中释放出来。免疫印迹显示免疫球蛋白和转铁蛋白以及白蛋白存在于刺激的中性粒细胞的胞外物质中。这表明分泌囊泡是一种独特的内吞囊泡，可以在炎症刺激下被触发排出。
In search for matrix proteins released from secretory vesicles of human neutrophils, a prominent 67-kD protein was identified in the extracellular medium of neutrophils stimulated by the chemotactic peptide, FMLP. The protein was purified to apparent homogeneity and partially sequenced. The sequence of the first 32 NH2-terminal amine acids was identical to the sequence of albumin. mRNA for human albumin could not be detected in bone marrow cells, nor could biosynthetic labeling of albumin be demonstrated in bone marrow cells during incubation with [C-14] leucine.Immunofluorescence studies on single cells demonstrated the presence of intracellular albumin in fixed permeabilized neutrophils. Light microscopy of immunogold-silver-stained cryosections visualized albumin in cytoplasmic "granules." The morphology of these was determined by immunoelectron microscopy as vesicles of varying form and size. Subcellular fractionation studies on unstimulated neutrophils demonstrated the presence of albumin in the low density pre-gamma and gamma-regions that contain secretory vesicles, but are devoid of specific granules and azurophil granules. Albumin was readily released from these structures during activation of neutrophils with inflammatory mediators. Immunoblotting demonstrated the presence of immunoglobulin and transferrin along with albumin in exocytosed material from stimulated neutrophils. This indicates that secretory vesicles are unique endocytic vesicles that can be triggered to exocytose by inflammatory stimuli.