Data from: Increasing procaspase 8 expression using repurposed drugs to induce HIV infected cell death in ex vivo patient cells

HIV persists because a reservoir of latently infected CD4 T cells do not express viral proteins and are indistinguishable from uninfected cells. One approach to HIV cure suggests that reactivating HIV will activate cytotoxic pathways; yet when tested in vivo, reactivating cells do not die sufficiently to reduce cell-associated HIV DNA levels. We recently showed that following reactivation from latency, HIV infected cells generate the HIV specific cytotoxic protein Casp8p41 which is produced by HIV protease cleaving procaspase 8. However, cell death is prevented, possibly due to low procaspase 8 expression. Here, we tested whether increasing procaspase 8 levels in CD4 T cells will produce more Casp8p41 following HIV reactivation, causing more reactivated cells to die. Screening 1277 FDA approved drugs identified 168 that increased procaspase 8 expression by at least 1.7-fold. Of these 30 were tested for anti-HIV effects in an acute HIVIIIb infection model, and 9 drugs at physiologic relevant levels significantly reduced cell-associated HIV DNA. Primary CD4 T cells from ART suppressed HIV patients were treated with one of these 9 drugs and reactivated with αCD3/αCD28. Four drugs significantly increased Casp8p41 levels following HIV reactivation, and decreased total cell associated HIV DNA levels (flurbiprofen: p = 0.014; doxycycline: p = 0.044; indomethacin: p = 0.025; bezafibrate: P = 0.018) without effecting the viability of uninfected cells. Thus procaspase 8 levels can be increased pharmacologically and, in the context of HIV reactivation, increase Casp8p41 causing death of reactivating cells and decreased HIV DNA levels. Future studies will be required to define the clinical utility of this or similar approaches.人类免疫缺陷病毒（HIV）之所以能够持续感染宿主，是因为潜伏感染的CD4 T细胞（CD4 T cells）库不表达病毒蛋白，与未感染的正常细胞难以区分。目前一种HIV治愈策略提出，激活潜伏的HIV可触发细胞毒性通路；然而在体内实验中，被激活的感染细胞并未发生足够程度的死亡，无法降低细胞结合型HIV DNA（cell-associated HIV DNA）水平。我们此前的研究发现，从潜伏状态被激活后，HIV感染细胞会产生HIV特异性细胞毒性蛋白Casp8p41，该蛋白由HIV蛋白酶（HIV protease）切割procaspase 8（半胱天冬氨酸蛋白酶8前体）生成。但感染细胞的死亡过程被阻断，这可能源于procaspase 8的低表达水平。本研究中，我们通过实验验证，提高CD4 T细胞内procaspase 8的表达水平，是否能在HIV被激活后生成更多Casp8p41，从而促使更多被激活的感染细胞发生死亡。我们对1277种美国食品药品监督管理局（Food and Drug Administration, FDA）批准的药物进行筛选，最终鉴定出168种可使procaspase 8的表达水平至少上调1.7倍的药物。我们从这168种药物中选取30种，在急性HIVIIIb感染模型中测试其抗HIV活性，最终有9种药物在生理相关浓度下可显著降低细胞结合型HIV DNA水平。我们将来自接受抗逆转录病毒治疗（Antiretroviral Therapy, ART）且病毒载量被抑制的HIV患者的原代CD4 T细胞，用上述9种药物中的一种进行处理，随后用抗CD3/抗CD28抗体（αCD3/αCD28）激活细胞。其中4种药物可显著提升HIV激活后Casp8p41的表达水平，并降低总细胞结合型HIV DNA水平（氟比洛芬：p=0.014；多西环素：p=0.044；吲哚美辛：p=0.025；苯扎贝特：P=0.018），且不会影响未感染细胞的存活率。综上，可通过药理学手段提高procaspase 8的表达水平；在HIV激活的背景下，这可增加Casp8p41的生成，促使被激活的感染细胞死亡，并降低HIV DNA水平。未来仍需开展相关研究，以明确该策略或类似策略的临床应用价值。