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发表于 2014-5-5 21:46:35
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颗粒酶和穿孔素常表达于细胞毒T和NK细胞中。给你两段英文介绍：
Perforin
Perforin, also known as cytolysin or C9RP (complement 9 related protein), is a 70 kD protein structurally similar to complement C9 component, and it is encoded by a gene located on the long arm of chromosome 10 . Once secreted on the target cell, perforin perforates the membrane and forms pores or channels that enable the granzyme molecules simultaneously secreted to enter the target.
In steady state, perforin can be detected in NK cells , gamma/delta TCR T cells , and the subset of alpha/beta TCR T cells expressing CD11b . After in vitro activation with anti-CD3 and IL-2, perforin expression increases and the molecule becomes detectable also in some 50% of CD8＋ CD11b– T cells, and in a small subset of CD4＋ lymphocytes . Perforin is undetectable in resting CD34＋ bone marrow cells, but it is present in the CD34＋ KG1a cell line. It is also expressed in peripheral CD34＋ cells after mobilization with G-CSF and chemotherapy but not with G-CSF alone .
Granzymes
Granzymes are a family of serine proteases stored in the granules of cytotoxic T lymphocytes and NK cells , which are able to induce apoptosis in target cells through activation of the caspase pathway Granzymes A, B and M are of interest in the diagnosis of hematological malignancies. These proteases differ according to their molecular binding sites, namely (i) arginine and lysine , (ii) aspartic acid , and (iii) methionine, leucine and norleucine , respectively.
Granzymes A and B are proteins of about 28–29 kD and are encoded by genes situated on the long arm of chromosome 5 and chromosome 14 , respectively. In resting conditions, granzyme positive cells are detectable in red pulp of the spleen, in tonsils, lymph nodes, liver, thymus and among lamina propria lymphocytes of the gut . In steady state, peripheral blood granzyme is detectable in CD3– CD16＋ CD56＋ NK cells only . According to some authors, granzymes A and B are equally distributed , while according to others the granzyme type distribution may depend on cell type and functional state . Intraepithelial gut T cells may express granzyme A in steady state, but also co-express granzyme B upon activation . Plasmacytoid dendritic cells have been demonstrated to serve as a source of granzyme B physiologically able to switch off T cell proliferation .
Some authors have postulated the presence of granzymes A and B and perforin in neutrophils , but others deny this fi nding .
Like perforin, granzyme B is undetectable in resting CD34＋ bone marrow cells, but is present in the CD34＋ KG1a cell line. It is also expressed in peripheral CD34＋ cells after mobilization with G-CSF and chemotherapy but not with G-CSF alone .
Granzyme M is usually detectable in NK cells, gamma/ delta TCR T Lymphocytes and the small T CD56＋ cell subset .
至于染色方法，常规的胞内染色方法即可。
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发表于 2014-5-5 21:28:28
