Altered telomere maintenance mechanism (TMM) is linked to increased DNA damage at telomeres and telomere uncapping. We previously showed that HIV-1 latent cells have altered TMM and are susceptible to ligands that target G-quadruplexes (G4) at telomeres. Susceptibility of latent cells to telomere targeting could potentially be used to support approaches to eradicate HIV reservoirs. However, G4 ligands also target G-quadruplexes in promoters blocking gene transcription. Since HIV promoter sequence can form G-quadruplexes, we investigated whether G4 ligands interfere with HIV-1 promoter activity and virus reactivation from latency, and whether telomere targeting could be combined with latency reversing agents (LRAs) to promote elimination of HIV reservoirs. Our results indicate that Sp1 binding region in HIV-1 promoter can adopt G4 structures in duplex DNA, and that in vitro binding of Sp1 to G-quadruplex is blocked by G4 ligand, suggesting that agents targeting telomeres interfere with virus reactivation. However, our studies show that G4 agents do not affect HIV-1 promoter activity in cell culture, and do not interfere with latency reversal. Importantly, primary memory CD4 + T cells infected with latent HIV-1 are more susceptible to combined treatment with LRAs and G4 ligands, indicating that drugs targeting TMM may enhance killing of HIV reservoirs. Using a cell-based DNA repair assay, we also found that HIV-1 infected cells have reduced efficiency of DNA mismatch repair (MMR), and base excision repair (BER), suggesting that altered TMM in latently infected cells could be associated with accumulation of DNA damage at telomeres and changes in telomeric caps.

端粒维持机制（TMM）的改变与端粒DNA损伤增加和端粒解封有关。我们以前表明，HIV-1潜伏细胞已经改变了TMM，并且易受靶向端粒G-四链体（G4）的配体的影响。潜在细胞对端粒靶向的敏感性可潜在地用于支持根除HIV储库的方法。但是，G4配体还可以在启动子中靶向G-四链体，从而阻止基因转录。由于HIV启动子序列可以形成G-四链体，因此我们研究了G4配体是否会干扰HIV-1启动子的活性和潜伏期引起的病毒再激活，以及端粒靶向是否可以与潜伏期逆转剂（LRA）结合使用以促进消除HIV库。Sp1与G-四链体的体外结合被G4配体阻断，这表明靶向端粒的药物会干扰病毒的激活。但是，我们的研究表明，G4剂不会影响细胞培养物中HIV-1启动子的活性，并且不会干扰潜伏期的逆转。重要的是，感染了潜在HIV-1的原代记忆CD4 + T细胞更容易接受LRA和G4配体的联合治疗，这表明靶向TMM的药物可能会增强对HIV储库的杀死。使用基于细胞的DNA修复测定法，我们还发现HIV-1感染的细胞降低了DNA错配修复（MMR）和碱基切除修复（BER）的效率，这表明潜伏感染细胞中TMM的改变可能与积累有关端粒的DNA损伤和端粒帽的变化。