Rochat M A, Schlaepfer E, Speck R F
Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland.
J Virol. 2017 Jan 31;91(4). doi: 10.1128/JVI.02084-16. Print 2017 Feb 15.
The persistence of latently HIV-infected cells in patients under combined antiretroviral treatment (cART) remains the major hurdle for HIV eradication. Thus far, individual compounds have not been sufficiently potent to reactivate latent virus and guarantee its elimination in vivo. Thus, we hypothesized that transcriptional enhancers, in concert with compounds triggering the innate immune system, are more efficient in reversing latency by creating a Th1 supportive milieu that acts against latently HIV-infected cells at various levels. To test our hypothesis, we screened six compounds on a coculture of latently infected cells (J-lat) and monocyte-derived dendritic cells (MDDCs). The protein kinase C (PKC) agonist prostratin, with a Toll-like receptor 8 (TLR8) agonist, resulted in greater reversion of HIV latency than any single compound. This combinatorial approach led to a drastic phenotypic and functional maturation of the MDDCs. Tumor necrosis factor (TNF) and cell-cell interactions were crucial for the greater reversion observed. Similarly, we found a greater potency of the combination of prostratin and TLR8 agonist in reversing HIV latency when applying it to primary cells of HIV-infected patients. Thus, we demonstrate here the synergistic interplay between TLR8-matured MDDCs and compounds acting directly on latently HIV-infected cells, targeting different mechanisms of latency, by triggering various signaling pathways. Moreover, TLR8 triggering may reverse exhaustion of HIV-specific cytotoxic T lymphocytes that might be essential for killing or constraining the latently infected cells.
Curing HIV is the Holy Grail. The so-called "shock and kill" strategy relies on drug-mediated reversion of HIV latency and the subsequent death of those cells under combined antiretroviral treatment. So far, no compound achieves efficient reversal of latency or eliminates this latent reservoir. The compounds may not target all of the latency mechanisms in all latently infected cells. Moreover, HIV-associated exhaustion of the immune system hinders the efficient elimination of the reactivated cells. In this study, we demonstrated synergistic latency reversion by combining agonists for protein kinase C and Toll-like receptor 8 in a coculture of latently infected cells with myeloid dendritic cells. The drug prostratin stimulates directly the transcriptional machinery of latently infected cells, and the TLR8 agonist acts indirectly by maturing dendritic cells. These findings highlight the importance of the immune system and its activation, in combination with direct-acting compounds, to reverse latency.
在接受联合抗逆转录病毒治疗（cART）的患者中，潜伏感染HIV的细胞持续存在仍然是根除HIV的主要障碍。到目前为止，单一化合物的效力不足以重新激活潜伏病毒并保证其在体内被清除。因此，我们假设转录增强剂与触发先天免疫系统的化合物协同作用，通过创造一个在各个层面作用于潜伏感染HIV细胞的Th1支持性微环境，能更有效地逆转潜伏期。为了验证我们的假设，我们在潜伏感染细胞（J-lat）和单核细胞衍生树突状细胞（MDDC）的共培养物上筛选了六种化合物。蛋白激酶C（PKC）激动剂prostratin与Toll样受体8（TLR8）激动剂联合使用，比任何单一化合物都能更有效地逆转HIV潜伏期。这种联合方法导致了MDDC显著的表型和功能成熟。肿瘤坏死因子（TNF）和细胞间相互作用对于观察到的更大程度的逆转至关重要。同样，当将prostratin和TLR8激动剂的组合应用于HIV感染患者的原代细胞时，我们发现其在逆转HIV潜伏期方面具有更大的效力。因此，我们在此证明了TLR8成熟的MDDC与直接作用于潜伏感染HIV细胞的化合物之间的协同相互作用，通过触发各种信号通路，针对不同的潜伏期机制。此外，TLR8激活可能会逆转HIV特异性细胞毒性T淋巴细胞的耗竭，这对于杀死或限制潜伏感染细胞可能至关重要。
治愈HIV是圣杯。所谓的“激活并清除”策略依赖于药物介导的HIV潜伏期逆转以及随后在联合抗逆转录病毒治疗下这些细胞的死亡。到目前为止，没有一种化合物能有效逆转潜伏期或消除这个潜伏库。这些化合物可能无法针对所有潜伏感染细胞中的所有潜伏期机制。此外，HIV相关的免疫系统耗竭阻碍了对重新激活细胞的有效清除。在这项研究中，我们在潜伏感染细胞与髓样树突状细胞的共培养物中，通过联合蛋白激酶C和Toll样受体8的激动剂，证明了协同潜伏期逆转。药物prostratin直接刺激潜伏感染细胞的转录机制，而TLR8激动剂通过使树突状细胞成熟间接发挥作用。这些发现凸显了免疫系统及其激活与直接作用化合物相结合以逆转潜伏期的重要性。
