長(zhǎng)期以來(lái)醫(yī)學(xué)界認(rèn)為，人體免疫系統(tǒng)對(duì)已進(jìn)入細(xì)胞內(nèi)部的病毒束手無(wú)策,。但英國(guó)一項(xiàng)最新研究發(fā)現(xiàn),，一些抗體能夠隨病毒進(jìn)入人體細(xì)胞內(nèi)部，并在細(xì)胞內(nèi)一種蛋白質(zhì)的作用下引發(fā)摧毀病毒的連鎖反應(yīng),，這一發(fā)現(xiàn)將有助于研發(fā)新的抗病毒藥物,。
位于英國(guó)劍橋的分子生物學(xué)實(shí)驗(yàn)室等機(jī)構(gòu)研究人員在新一期美國(guó)《國(guó)家科學(xué)院學(xué)報(bào)》上報(bào)告說(shuō)，他們發(fā)現(xiàn)人體免疫系統(tǒng)生成的抗體在血液中遇到病毒后,，會(huì)一直附著其上,，即使一些病毒穿過(guò)細(xì)胞膜進(jìn)入了人體細(xì)胞，抗體也仍然附著于這些病毒表面,。而人體細(xì)胞內(nèi)部一種名為T(mén)RIM21的蛋白質(zhì)會(huì)發(fā)現(xiàn)這些抗體,，并激活細(xì)胞內(nèi)部的“垃圾處理系統(tǒng)”，在較短時(shí)間內(nèi)將病毒消滅,。
研究人員已經(jīng)開(kāi)始嘗試在此基礎(chǔ)上研發(fā)新的抗病毒藥物,。初步實(shí)驗(yàn)顯示，在增加細(xì)胞中TRIM21蛋白質(zhì)的含量后,，細(xì)胞消滅病毒的能力大大提高,。（生物谷Bioon.com）
更多閱讀
Cell：microRNA調(diào)控免疫系統(tǒng)
JCB：巨細(xì)胞病毒躲避免疫系統(tǒng)的機(jī)制
J.Immuno.：細(xì)菌提高免疫系統(tǒng)的機(jī)制
PLoS Pathog：艾滋病病毒運(yùn)用多種策略逃避免疫系統(tǒng)
Nature Medicine：兩分子聯(lián)手可破壞人體免疫系統(tǒng)
JEM：一種人體免疫系統(tǒng)的新控制機(jī)制
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1014074107
Antibodies mediate intracellular immunity through tripartite motif-containing 21 (TRIM21)
Donna L. Mallerya,1, William A. McEwana,1, Susanna R. Bidgooda,1, Greg J. Towersb, Chris M. Johnsona, and Leo C. Jamesa,2
aProtein and Nucleic Acid Chemistry Division, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom; and
bDivision of Infection and Immunity, Medical Research Council Centre for Medical Molecular Virology, University College London, London W1T4JF, United Kingdom
Antibodies provide effective antiviral immunity despite the fact that viruses escape into cells when they infect. Here we show that antibodies remain attached to viruses after cell infection and mediate an intracellular immune response that disables virions in the cytosol. We have discovered that cells possess a cytosolic IgG receptor, tripartite motif-containing 21 (TRIM21), which binds to antibodies with a higher affinity than any other IgG receptor in the human body. TRIM21 rapidly recruits to incoming antibody-bound virus and targets it to the proteasome via its E3 ubiquitin ligase activity. Proteasomal targeting leads to rapid degradation of virions in the cytosol before translation of virally encoded genes. Infection experiments demonstrate that at physiological antibody concentrations TRIM21 neutralizes viral infection. These results reveal an intracellular arm of adaptive immunity in which the protection mediated by antibodies does not end at the cell membrane but continues inside the cell to provide a last line of defense against infection.
