英國一項(xiàng)最新研究顯示,，人體中名為自然殺傷細(xì)胞的免疫細(xì)胞擁有長繩狀的“遠(yuǎn)程攻擊武器”,，可將試圖逃跑的目標(biāo)細(xì)胞抓回或遠(yuǎn)程殺死。這一發(fā)現(xiàn)將有助于研發(fā)提高人體免疫力的藥物,。
英國帝國理工學(xué)院等機(jī)構(gòu)的研究人員在新一期美國PNAS上報(bào)告說,，通過使用一種細(xì)胞染色技術(shù)，可以在顯微鏡下看到自然殺傷細(xì)胞與其他細(xì)胞間形成的細(xì)絲狀“膜納米管”,。通常,，自然殺傷細(xì)胞會附著到發(fā)生病變的目標(biāo)細(xì)胞上并將其殺死，但有時(shí)候目標(biāo)細(xì)胞在接觸之后會試圖逃跑,，觀測顯示,，這時(shí)候自然殺傷細(xì)胞就會利用“膜納米管”將目標(biāo)細(xì)胞拉回，或是直接遠(yuǎn)程將其殺死,。
研究顯示，這種“遠(yuǎn)程攻擊武器”可以顯著增加自然殺傷細(xì)胞殺死遠(yuǎn)處目標(biāo)細(xì)胞的效率,，成功率達(dá)75％,，而如果人為干涉切斷已形成的“膜納米管”，則成功率會降至5％,。參與研究的丹尼爾·戴維斯說,，如果能進(jìn)一步探明這種“膜納米管”工作的原理，將有助于研發(fā)提高人體免疫力的藥物,。
自然殺傷細(xì)胞是人體免疫系統(tǒng)對付病菌病毒的第一道防線,。如果發(fā)現(xiàn)被感染而發(fā)生病變的細(xì)胞，自然殺傷細(xì)胞就會附著其上,，傳遞毒素并將目標(biāo)細(xì)胞殺死,。(生物谷Bioon.com)
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.0910074107
Membrane nanotubes facilitate long-distance interactions between natural killer cells and target cells
Anne Chauveaua,b, Anne Auchera, Philipp Eissmanna, Eric Vivierb,c, and Daniel M. Davisa,1
Membrane nanotubes are membranous tethers that physically link cell bodies over long distances. Here, we present evidence that nanotubes allow human natural killer (NK) cells to interact functionally with target cells over long distances. Nanotubes were formed when NK cells contacted target cells and moved apart. The frequency of nanotube formation was dependent on the number of receptor/ligand interactions and increased on NK cell activation. Most importantly, NK cell nanotubes contained a submicron scale junction where proteins accumulated, including DAP10, the signaling adaptor that associates with the activating receptor NKG2D, and MHC class I chain-related protein A (MICA), a cognate ligand for NKG2D, as occurs at close intercellular synapses between NK cells and target cells. Quantitative live-cell fluorescence imaging suggested that MICA accumulated at small nanotube synapses in sufficient numbers to trigger cell activation. In addition, tyrosine-phosphorylated proteins and Vav-1 accumulated at such junctions. Functionally, nanotubes could aid the lysis of distant target cells either directly or by moving target cells along the nanotube path into close contact for lysis via a conventional immune synapse. Target cells moving along the nanotube path were commonly polarized such that their uropods faced the direction of movement. This is the opposite polarization than for normal cell migration, implying that nanotubes can specifically drive target cell movement. Finally, target cells that remained connected to an NK cell by a nanotube were frequently lysed, whereas removing the nanotube using a micromanipulator reduced lysis of these target cells.
