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.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）储存库不表达病毒蛋白，且与未感染细胞难以区分。目前针对HIV治愈的一种策略认为，激活HIV可启动细胞毒性通路；但在体内实验中，被激活的感染细胞死亡程度不足，无法降低细胞相关HIV DNA水平。我们近期的研究表明，HIV感染细胞从潜伏状态被激活后，会产生HIV特异性细胞毒性蛋白Casp8p41，该蛋白由HIV蛋白酶切割procaspase 8（半胱天冬酶8前体）生成。然而，感染细胞的死亡过程会被阻断，这可能是因为procaspase 8的表达水平较低。本研究中，我们测试了提升CD4 T细胞内procaspase 8的表达水平，能否在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种经美国食品药品监督管理局（FDA）批准的药物进行筛选，共发现168种可使procaspase 8的表达水平提升至少1.7倍。其中30种药物在急性HIVIIIb感染模型中被测试抗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相关HIV DNA水平。我们用这9种药物中的一种处理来自经抗逆转录病毒治疗（antiretroviral therapy, ART）后病毒被抑制的HIV感染者的原代CD4 T细胞，随后用αCD3/αCD28（抗CD3/抗CD28抗体）进行激活。其中4种药物在HIV被激活后可显著提升Casp8p41的表达水平，并降低总细胞相关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），且未对未感染细胞的存活率产生影响。综上，可通过药理学手段提升procaspase 8的表达水平，且在HIV激活的背景下，该操作可增加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。