人类为什么容易被HIV感染（SCIENCE）

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人类为什么容易被HIV感染（SCIENCE）
http://www.sciencemag.org/cgi/content/abstract/316/5832/1756
Restriction of an Extinct Retrovirus by the Human TRIM5 Antiviral Protein
Shari M. Kaiser,1,2 Harmit S. Malik,3 Michael
Primate genomes contain a large number of endogenous retroviruses and encode evolutionarily dynamic proteins that provide intrinsic immunity to retroviral infections. We report here the resurrection of the core protein of a 4-million-year-old endogenous virus from the chimpanzee genome and show that the human variant of the intrinsic immune protein TRIM5 can actively prevent infection by this virus. However, we suggest that selective changes that have occurred in the human lineage during the acquisition of resistance to this virus, and perhaps similar viruses, may have left our species more susceptible to infection by human immunodeficiency virus type
人类对HIV病毒的易感染性可能是因为人类祖先对一个古老病毒产生抵抗力的进化的结果。黑猩猩和其他一些灵长类对HIV这个存在了30万到40万年的病毒易感有抵抗力。这个 \"tERV1\"的病毒是一个内源性逆转录病毒，换句话说，它可以插入其宿主的生殖系从而能从一代传给下一代。黑猩猩和大猩猩的基因组中有100多个PtERV1的拷贝，但是在人类的基因组中没有发现。Shari Kaiser等人用黑猩猩的基因组重建了该病毒的核心蛋白质，并发现一个名为TRIM5-α的蛋白质的人类版本防止该病毒插入细胞。人类的TRIM5-α对HIV的防御比较差，而其他灵长类该蛋白的版本则提供对HIV的防御。作者认为，虽然早期人类进化出对PtERV1的抵抗力，但是代价就是对其他逆转录病毒比如HIV的抵抗力得下降。