Vimentin expressed on Mycobacterium tuberculosis-infected human monocytes is involved in binding to the NKp46 receptor
Vimentin expressed on Mycobacterium tuberculosis-infected human monocytes is involved in binding to the NKp46 receptor
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DOI：
10.4049/jimmunol.177.9.6192
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发表时间：
2006-11-01
影响因子：
4.4
通讯作者：
Vankayalapati, Ramakrishna
中科院分区：
文献类型：
--
作者：
Garg, Ankita;Barnes, Peter F.;Vankayalapati, Ramakrishna
我们先前表明，人类NK细胞使用NKp 46受体裂解结核分枝杆菌H37 Ra感染的单核细胞。为了鉴定H37 Ra感染的人单核吞噬细胞上的配体，我们使用抗NKp 46从与H37 Ra感染的单核细胞上的配体结合的NK细胞免疫沉淀NKp 46。质谱分析确定。一种57-kDa分子，波形蛋白，作为NKp 46的假定配体。与未感染的细胞相比，波形蛋白的表达在感染的单核细胞表面上显著上调，这通过荧光显微镜证实。抗波形蛋白抗血清抑制NK细胞裂解感染的单核细胞，而抗血清肌动蛋白，另一种丝状蛋白，没有。与用对照质粒转染的细胞相比，用波形蛋白构建体转染的CHO-K1细胞被NK细胞更有效地裂解。这种裂解被mAb介导的NKp 46（在NK细胞上）或波形蛋白（在感染的单核细胞上）的掩蔽所抑制。ELISA和Far Western blotting结果表明，重组vimentin与NKp 46融合蛋白结合。这些结果表明波形蛋白参与NKp 46与M的结合。结核H37 Ra感染的单核吞噬细胞。
We previously showed that human NK cells used the NKp46 receptor to lyse Mycobacterium tuberculosis H37Ra-infected monocytes. To identify ligands on H37Ra-infected human mononuclear phagocytes, we used anti-NKp46 to immunoprecipitate NKp46 from NK cells bound to its ligand(s) on H37Ra-infected monocytes. Mass spectrometry analysis identified. a 57-kDa molecule, vimentin, as a putative ligand for NKp46. Vimentin expression was significantly up-regulated on the surface of infected monocytes, compared with uninfected cells, and this was confirmed by fluorescence microscopy. Anti-vimentin antiserum inhibited NK cell lysis of infected monocytes, whereas antiserum to actin, another filamentous protein, did not. CHO-K1 cells transfected with a vimentin construct were lysed much more efficiently by NK cells than cells transfected with a control plasmid. This lysis was inhibited by mAb-mediated masking of NKp46 (on NK cells) or vimentin (on infected monocytes). ELISA and Far Western blotting showed that recombinant vimentin bound to a NKp46 fusion protein. These results indicate that vimentin is involved in binding of NKp46 to M. tuberculosis H37Ra-infected mononuclear phagocytes.