A Novel Mechanism of Restriction by an APOBEC3 Protein

项目摘要/摘要： 慢病毒都编码一种Vif蛋白，该蛋白已被证明与载脂蛋白成员相互作用 信使核糖核酸编辑，催化类多肽3(APOBEC3)蛋白质超家族。APOBEC3蛋白是 胞苷脱氨酶被认为在先天抗病毒免疫中发挥重要作用。人类和 猕猴都编码7个APOBEC3基因(A3A、A3B、A3C、A3D、A3F、A3G和A3H)。这个 APOBEC3蛋白大致可分为单脱氨酶结构域(A3A、A3C和A3H)和双脱氨酶结构域 脱氨酶结构域蛋白(A3B、A3D、A3F和A3G)。人A3A(HA3A)不限制复制 HIV-1vif在293细胞或HeLa细胞中，但最近被证明抑制HIVvif在293细胞或HeLa细胞中的复制 巨噬细胞衍生巨噬细胞(MDM)。相反，猕猴的rHA3A能够限制 HIV-1和SHV(表达SIV Vif)。我们最近评估了其他非人类的能力 灵长类A3A蛋白限制HIV-1和HIV-1vif。我们提供了来自A3A蛋白的初步数据 东半球的猴子Colobus guereza(披着斗篷的guereza，colA3A)不仅抑制了 HIV-1和HIV-1vif，但也抑制了生产细胞中的病毒生产。我们的初步研究表明 ColA3A通过一种新的进入后机制抑制，但不是在前病毒整合之后。在具体目标1中， 我们建议确定colA3A抑制HIV-1复制的机制，并评估 涉及到的分子决定因素。在特定的目标2中，我们建议确定colA3A在 人类CD4+T细胞和巨噬细胞可以限制其自然感染的细胞中的HIV-1。拟议的研究将 为A3蛋白抑制HIV-1的这一新机制提供机制洞察，这可能作为一种 针对HIV-1的新的抗病毒策略。

PROJECT SUMMARY/ABSTRACT: The lentiviruses all encode for a Vif protein that has been shown to interact with members of the apolipoprotein mRNA-editing, catalytic polypeptide-like 3 (APOBEC3) superfamily of proteins. The APOBEC3 proteins are cytidine deaminases that are thought to play an important role in innate anti-viral immunity. Humans and macaques both encode for seven APOBEC3 genes (A3A, A3B, A3C, A3D, A3F, A3G, and A3H). The APOBEC3 proteins can be broadly divided into the single deaminase domain (A3A, A3C, and A3H) and double deaminase domain proteins (A3B, A3D, A3F, and A3G). Human A3A (hA3A) does not restrict the replication of HIV-1vif in 293 cells or HeLa cells but has recently been shown to inhibit replication of HIVvif in macrophage-derived macrophages (MDM). In contrast, rhA3A from rhesus macaques is capable of restricting both HIV-1 and SHIV (expressing the SIV Vif). We recently have assessed the ability of other non-human primate A3A proteins to restrict HIV-1 and HIV-1vif. We present preliminary data that the A3A protein from the Old World monkey, Colobus guereza (the mantled guereza, colA3A), not only inhibits the replication of HIV-1 and HIV-1vif but also inhibits virus production in producer cells. Our preliminary studies indicate that the colA3A inhibits by a novel post-entry mechanism and, but not after, proviral integration. In Specific Aim 1, we propose to determine the mechanism though which colA3A inhibits HIV-1 replication and assess the molecular determinants involved. In Specific Aim 2, we propose to determine whether expression of colA3A in human CD4+ T cells and macrophages can restrict HIV-1 in cells it naturally infects. The proposed studies will provide mechanistic insight into this novel mechanism of A3 protein inhibition of HIV-1, which could serve as a new anti-viral strategy against HIV-1.