艾滋病治疗问题困扰人类多年，尽管鸡尾酒疗法曾在很长一段时间有效地控制了艾滋病，随着HIV病毒的协同进化，艾滋病耐药问题越来越严重，科学家们不得不另辟蹊径寻找新的抗艾武器，最新Blood杂志上刊发了一篇用干细胞治疗艾滋病的研究性成果文章。
来自加州大学艾滋病研究所的科学家（UCLA AIDS Institute）在研究艾滋病病毒结合人类细胞的过程中发现，人类细胞上的一个细胞受体CCR5，是艾滋病毒的结合受体，通过这个受体艾滋病毒才能结合到人类细胞上。
艾滋病研究所的科学家们尝试将这些受体蛋白从人类细胞上剥离开来，因为在临床研究中发现，缺乏CCR5受体的人群对艾滋病有天然的抵抗能力。
科学家们首先在模式动物上进行试验，他们选用人类化的小鼠为模型，往小鼠体内注入小RNA分子（短链发夹结构的RNA，shRNA），通过RNAi干扰机制阻断小鼠体内的人体血液干细胞CCR5受体的表达。
令人欣喜的是，CCR5受体表达受阻的小鼠对艾滋病表现出稳定的抵抗力。
科学家们认为，这一研究成果证实了，使用RNAi技术阻断CCR5受体的治疗方式可能成为治疗HIV的好办法。
A highly efficient short hairpin RNA potently down-regulates CCR5 expression in systemic lymphoid organs in the hu-BLT mouse model
Inhibiting the expression of the HIV-1 coreceptor CCR5 holds great promise for controlling HIV-1 infection in patients. Here we report stable knockdown of human CCR5 by a short hairpin RNA (shRNA) in a humanized bone marrow/liver/thymus (BLT) mouse model. We delivered a potent shRNA against CCR5 into human fetal liver-derived CD34+ hematopoietic progenitor/stem cells (HPSCs) by lentiviral vector transduction. We transplanted vector-transduced HPSCs solidified with Matrigel and a thymus segment under the mouse kidney capsule. Vector-transduced autologous CD34+ cells were subsequently injected in the irradiated mouse, intended to create systemic reconstitution. CCR5 expression was down-regulated in human T cells and monocytes/macrophages in systemic lymphoid tissues, including gut-associated lymphoid tissue, the major site of HIV-1 replication. The shRNA-mediated CCR5 knockdown had no apparent adverse effects on T-cell development as assessed by polyclonal T-cell receptor Vβ family development and naive/memory T-cell differentiation. CCR5 knockdown in the secondary transplanted mice suggested the potential of long-term hematopoietic reconstitution by the shRNA-transduced HPSCs. CCR5 tropic HIV-1 infection was effectively inhibited in mouse-derived human splenocytes ex vivo. These results demonstrate that lentiviral vector delivery of shRNA into human HPSCs could stably down-regulate CCR5 in systemic lymphoid organs in vivo.
