Potent inhibition of HIV-1 latency reversal by PF 03758309

总结 潜伏的、有复制能力的HIV-1前病毒在静息的CD 4 + T细胞中的持续存在代表了一个主要的 治疗HIV-1感染的障碍。迄今为止，通过休克和杀死方法根除这种病毒储存库的努力 在细胞和/或动物模型中没有导致完全的、长期的病毒抑制。因此，我们需要 考虑可能导致HIV-1感染的绝育或功能性治愈的替代方法。块 和锁定方法寻求沉默潜伏前病毒的转录活性，这样当抗逆转录病毒 如果去除抗逆转录病毒疗法（ART），则病毒反弹被显著延迟，或者更好地被预防。几个研究 研究小组已经鉴定出针对HIV-1转录的不同因子的小分子抑制剂 机械，导致阻断和锁定表型。然而，仅阻断一条转录途径可能不会 足以使所有前病毒沉默，因此，成功实施这一策略可能将 需要抑制剂的组合。在这方面，迫切需要鉴定具有不同结构的新分子。 行动机制。本实验室最近发现，p21激活激酶（PAK）抑制剂PF- 03758309是一种非常有效的HIV-1潜伏期再激活抑制剂（IC 50在pM至低nM范围内）， 一个巨大的选择性指数（> 3，000）。(The发现PF-03758309是HIV-1潜伏期逆转的抑制剂， 描述于：Vargas B，Giacobbi NS，Sanyal A，Venkatachari NJ，Han F，Gupta P，Sluis-Cremer N. 抗微生物剂Chemother。阻断HIV-1潜伏期抑制的信号通路抑制剂。2019 Jan 29;63（2）. pii：e01744-18.）从长远来看，我们预计PF-03758309单独或与 其他药物，可用于促进艾滋病毒感染者的“封锁”绝育治疗。然而，在这方面， 我们不知道这种抑制剂消除潜伏的HIV-1感染再激活的机制， CD 4 + T细胞。事实上，我们实验室的初步研究表明，它抑制HIV-1潜伏期逆转， 不是由于PAK的抑制。因此，本R21提案的主要目标是阐明 PF-03758309沉默HIV-1前病毒的机制。

SUMMARY The persistence of latent, replication-competent HIV-1 proviruses in resting CD4+ T cells represents a major barrier to curing HIV-1 infection. To date, efforts to eradicate this viral reservoir via the shock and kill approach have not led to complete, long term viral suppression in either cell and/or animal models. Thus, we need to consider alternate approaches that could lead to a sterilizing or functional cure for HIV-1 infection. The block and lock approach seeks to silence the transcriptional activity of latent proviruses, such that when antiretroviral therapy (ART) is removed viral rebound is significantly delayed or, better yet, prevented. Several research groups have identified small molecule inhibitors that target different factors of the HIV-1 transcription machinery, leading to a block and lock phenotype. However, blocking only one transcription pathway may not be sufficient to silence all proviruses, and thus it is likely that successful implementation of this strategy will require a combination of inhibitors. In this regard, there is a critical need to identify new molecules with different mechanisms of action. Our laboratory recently discovered that the p21-activated kinase (PAK) inhibitor PF- 03758309 is an exceptionally potent inhibitor of HIV-1 latency reactivation (IC50 in the pM to low nM range) with a huge selectivity index (> 3,000). (The discovery of PF-03758309 as an inhibitor of HIV-1 latency reversal is described in: Vargas B, Giacobbi NS, Sanyal A, Venkatachari NJ, Han F, Gupta P, Sluis-Cremer N. Antimicrob Agents Chemother. Inhibitors of Signaling Pathways That Block Reversal of HIV-1 Latency. 2019 Jan 29;63(2). pii: e01744-18.) In the long term, we anticipate that PF-03758309 alone, or in combination with other drugs, could be used to facilitate a “block and lock” sterilizing cure in HIV-infected individuals. However, we do not know the mechanism(s) by which this inhibitor abrogates the reactivation of latent HIV-1 infection in CD4+ T cells. Indeed, preliminary studies in our laboratory revealed that its inhibition of HIV-1 latency reversal is not due to inhibition of the PAKs. Accordingly, the primary goal of this R21 proposal is to elucidate the mechanism(s) by which PF-03758309 silences HIV-1 proviruses.