美国科研人员最近利用基因技术成功遏制老鼠体内的艾滋病病毒，这一方法为控制艾滋病病毒增殖提供了新思路。

这一技术的关键在于负责指导合成CCR5蛋白的一种基因。CCR5蛋白是艾滋病病毒入侵机体细胞的“帮凶”。科研人员很早就发现，如果CCR5蛋白基因发生有利的变异，那么人体就可能出现针对艾滋病病毒的免疫抵抗力。

美国南加州大学的葆拉·坎农等人在新一期英国《自然－生物技术》（Nature Biotechnology）杂志上报告说，他们用老鼠做实验时，借助一种名为cutter的酶，删除了未成熟造血细胞中的CCR5蛋白基因，因此这些细胞成熟分化时不会产生CCR5蛋白。

研究人员把这些细胞注入感染了艾滋病病毒的老鼠体内，并把它们与感染艾滋病病毒的普通老鼠进行比较，结果发现12周后在接受注射的老鼠体内，免疫T细胞水平有所恢复，艾滋病病毒含量保持在较低水平。而对照组老鼠的免疫系统能力减弱，艾滋病病毒大量分裂增殖。

坎农说，科研人员今后面临的挑战是如何将这一基因治疗技术用于人类。

原文出处：

Nature Biotechnology  doi:10.1038/nbt.1663

Human hematopoietic stem/progenitor cells modified by zinc-finger nucleases targeted to CCR5 control HIV-1 in vivo
Nathalia Holt,Jianbin Wang,Kenneth Kim,Geoffrey Friedman,Xingchao Wang,Vanessa Taupin,Gay M Crooks,Donald B Kohn,Philip D Gregory,Michael C Holmes& Paula M Cannon

CCR5 is the major HIV-1 co-receptor, and individuals homozygous for a 32-bp deletion in CCR5 are resistant to infection by CCR5-tropic HIV-1. Using engineered zinc-finger nucleases (ZFNs), we disrupted CCR5 in human CD34+ hematopoietic stem/progenitor cells (HSPCs) at a mean frequency of 17% of the total alleles in a population. This procedure produces both mono- and bi-allelically disrupted cells. ZFN-treated HSPCs retained the ability to engraft NOD/SCID/IL2rγnull mice and gave rise to polyclonal multi-lineage progeny in which CCR5 was permanently disrupted. Control mice receiving untreated HSPCs and challenged with CCR5-tropic HIV-1 showed profound CD4+ T-cell loss. In contrast, mice transplanted with ZFN-modified HSPCs underwent rapid selection for CCR5?/? cells, had significantly lower HIV-1 levels and preserved human cells throughout their tissues. The demonstration that a minority of CCR5?/? HSPCs can populate an infected animal with HIV-1-resistant, CCR5?/? progeny supports the use of ZFN-modified autologous hematopoietic stem cells as a clinical approach to treating HIV-1.