艾滋病一直令人谈之色变。即使在医学高度发达的今天,医学工作者仍没有找到一种方法治愈这种疾病。此前一段时间,一些包括艾滋病疫苗在内的疗法虽然取得了一定的进展,但距离彻底征服这一疾病仍有很长一段时间的距离。甚至在不久之前,通过早期治疗手段,已经宣称“治愈”的密西西比婴儿,最终仍然出现了病情反复的情况。这其中一个重要原因就是在HIV感染者体内有相当一部分病毒是“潜伏”在细胞内部的,而这部分HIV病毒很难被药物清除。
然而,科学研究中总是充满着这样或那样的惊喜。最近来自加州大学戴维分校的科学家发表在PLoS Pathogens的一项研究显示,一种名为PEP005(ingenol-3-angelate)的抗癌药物或许能够在防治艾滋病的战斗中起到非同寻常的作用。
这种药物原本被设计用于防治皮肤晒伤后皮肤癌的发生。研究发现在体内/体外条件下,PEP005能够通过诱导pS643/S676-PKCδ/θ-IκBα/ε-NF-κB 信号通路来使HIV携带者体内初始CD4+ T细胞内的HIV病毒RNA表达并最终使处于潜伏期的HIV病毒激活。更进一步,研究人员还寻找到一种名为JQ1的P-TEFb激活剂能够与PEP005产生协同作用,二者结合后是单独使用PEP005效果的7.5倍。
参与这一研究的Dr Satya Dandekar表示,PEP005的效果令人出乎意料,它有望在未来艾滋病治疗中起到重要作用。不过,Dr Satya Dandekar同时也承认,现有研究还处于非常初步的阶段,他们尚未在HIV阳性的患者体内检测这种药物的疗效。同时,他们还指出尽管PEP005已经广泛用于肿瘤治疗中,但是在艾滋病患者体内治疗时的疗效和毒副作用仍然需要重新评估。事实上,PEP005的研制代表着目前艾滋病疗法的一个思路。那就是通过刺激患者体内处于潜伏期的HIV病毒激活、释放来达到“斩草除根”的效果。
就好像亚历山大·弗莱明发现青霉素一样,让我们期待这一个美丽的意外能够为人类健康带来什么样的改变。
文章题目: Synergistic Reactivation of Latent HIV Expression by Ingenol-3-Angelate, PEP005, Targeted NF-kB Signaling in Combination with JQ1 Induced p-TEFb Activation.
Abstract Although anti-retroviral therapy (ART) is highly effective in suppressing HIV replication, it fails to eradicate the virus from HIV-infected individuals. Stable latent HIV reservoirs are rapidly established early after HIV infection. Therefore, effective strategies for eradication of the HIV reservoirs are urgently needed. We report that ingenol-3-angelate (PEP005), the only active component in a previously FDA approved drug (PICATO) for the topical treatment of precancerous actinic keratosis, can effectively reactivate latent HIV in vitro and ex vivo with relatively low cellular toxicity. Biochemical analysis showed that PEP005 reactivated latent HIV through the induction of the pS643/S676-PKCδ/θ-IκBα/ε-NF-κB signaling pathway. Importantly, PEP005 alone was sufficient to induce expression of fully elongated and processed HIV RNAs in primary CD4+ T cells from HIV infected individuals receiving suppressive ART. Furthermore, PEP005 and the P-TEFb agonist, JQ1, exhibited synergism in reactivation of latent HIV with a combined effect that is 7.5-fold higher than the effect of PEP005 alone. Conversely, PEP005 suppressed HIV infection of primary CD4+ T cells through down-modulation of cell surface expression of HIV co-receptors. This anti-cancer compound is a potential candidate for advancing HIV eradication strategies.
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