Kwaa Abena K, Goldsborough Kennedy, Walker-Sperling Victoria E, Pianowski Luiz F, Gama Lucio, Blankson Joel N
Center for AIDS Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
Kyolab, Campinas, Brazil.
PLoS One. 2017 May 3;12(5):e0174516. doi: 10.1371/journal.pone.0174516. eCollection 2017.
Some latency-reversing agents (LRAs) inhibit HIV-specific CD8+ T cell responses. In a prior study of protein kinase C (PKC) agonists, we found that bryostatin-1 inhibited elite controller/suppressor (ES) CD8+ T cell suppressive activity whereas prostratin had no effect. Ingenol-B is another PKC agonist with potent LRA activity both by itself and in combination with the bromodomain inhibitor JQ1; however its effect on CD8+ T cell mediated control of HIV-1 replication is unknown.
CD8+ T cells were isolated from ES and treated with bryostatin-1, prostratin, ingenol-B, and JQ1 as well as a combination of each PKC-agonist with JQ1. The cells were then tested in the viral suppression assay. To assess possible mechanisms of inhibition, CD8+ T cells were treated with the LRAs and analyzed for the expression of various immune cell markers.
Ingenol-B had no effect on the ability of ES CD8+ T cells to suppress viral replication, however, the combination of ingenol-B and JQ1 caused a modest, but significant decrease in this suppressive capacity. The mechanism of the inhibitory effect of the JQ1 and ingenol-B combination relative to ingenol-B alone was unclear but the effect appeared to be dose dependent.
Ingenol-B does not inhibit HIV-specific CD8+ T cell responses in vitro. These responses are however modestly inhibited when 100 nMingenol-B is combined with JQ1. Since HIV-specific CD8+ T cell activity may be essential for the eradication of reactivated latently infected cells, the potency of latency-reversal activity of drug combinations must be balanced against the effects of the combinations on HIV-specific CD8+ T cell responses.
一些潜伏期逆转剂（LRA）会抑制HIV特异性CD8 + T细胞反应。在先前一项关于蛋白激酶C（PKC）激动剂的研究中，我们发现苔藓抑素-1可抑制精英控制者/抑制者（ES）CD8 + T细胞的抑制活性，而原锥虫素则无此作用。大戟醇-B是另一种PKC激动剂，其本身以及与溴结构域抑制剂JQ1联合使用时均具有强大的LRA活性；然而，其对CD8 + T细胞介导的HIV-1复制控制的影响尚不清楚。
从ES中分离出CD8 + T细胞，并用苔藓抑素-1、原锥虫素、大戟醇-B、JQ1以及每种PKC激动剂与JQ1的组合进行处理。然后在病毒抑制试验中对细胞进行检测。为评估可能的抑制机制，用LRA处理CD8 + T细胞，并分析各种免疫细胞标志物的表达。
大戟醇-B对ES CD8 + T细胞抑制病毒复制的能力没有影响，然而，大戟醇-B与JQ1的组合导致这种抑制能力出现适度但显著的下降。JQ1与大戟醇-B组合相对于单独使用大戟醇-B的抑制作用机制尚不清楚，但这种作用似乎具有剂量依赖性。
大戟醇-B在体外不抑制HIV特异性CD8 + T细胞反应。然而，当100 nM大戟醇-B与JQ1联合使用时，这些反应会受到适度抑制。由于HIV特异性CD8 + T细胞活性对于根除重新激活的潜伏感染细胞可能至关重要，因此药物组合的潜伏期逆转活性效力必须与这些组合对HIV特异性CD8 + T细胞反应的影响相平衡。
