Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA.
J Acquir Immune Defic Syndr. 2012 Dec 1;61(4):417-24. doi: 10.1097/QAI.0b013e3182653c1f.
Combination drug therapy has reduced plasma HIV to undetectable levels; however, drug-sensitive virus persists in patients' lymphoid tissue. We have reported significant lymphoid tissue drug localization with indinavir-associated lipid nanoparticles (LNPs). Our current objective is to evaluate whether additional enhancement is achievable by targeting these particles to CD4-HIV host cells.
We characterized 2 peptide-coated (CD4-BP2 and CD4-BP4) drug-associated LNPs and demonstrated CD4-cell specificity. Drug-associated LNPs expressing polyethyleneglycol were exposed on HIV-2-infected cells under dynamic conditions that emulated lymph node physiology for 15, 30, and 60 minutes at concentrations from 0 to 25 μM and evaluated for antiviral activity and cell-associated drug concentrations. The specificity of CD4-mediated enhancement of indinavir LNPs antiviral activity was evaluated by blocking with anti-CD4 antibody.
Inclusion of CD4-binding peptides on LNPs enhanced antiviral activity for all incubation conditions, compared with control particles or soluble drug (eg, 60 minutes exposure, EC50 = 0.12-0.13 vs. 0.46 μM for targeted nanoparticles vs. soluble drug). The CD4-BP4 peptide exhibited higher efficiency in eliciting antiviral activity than CD4-BP2-coated particles (EC50 = 7.5 μM vs. >25 μM at 15 minutes drug exposure). This enhancement seems to be driven by CD4 availability and cell-associated indinavir concentrations, as blocking of CD4 significantly ablated indinavir efficacy in targeted particles and indinavir concentrations reflected the observed anti-HIV activity.
We constructed CD4-targeted LNPs that provide selective binding and efficient delivery of indinavir to CD4-HIV host cells. Inclusion of polyethyleneglycol in LNPs would minimize immune recognition of peptides. The enhancement of anti-HIV effects is effective even under limited time exposure.
联合药物治疗已将血浆 HIV 降低到无法检测的水平；然而，药物敏感病毒仍存在于患者的淋巴组织中。我们已经报道了与沙奎那韦相关的脂纳米颗粒（LNPs）存在显著的淋巴组织药物定位。我们目前的目标是评估通过将这些颗粒靶向 CD4-HIV 宿主细胞是否可以实现额外的增强。
我们对 2 种肽包被的（CD4-BP2 和 CD4-BP4）与药物相关的 LNPs 进行了表征，并证明了它们对 CD4 细胞的特异性。在模拟淋巴结生理学的动态条件下，将表达聚乙二醇的与药物相关的 LNPs 暴露于感染 HIV-2 的细胞上，浓度从 0 到 25 μM，孵育 15、30 和 60 分钟，评估抗病毒活性和细胞相关药物浓度。通过用抗 CD4 抗体阻断来评估 CD4 介导的增强与沙奎那韦 LNPs 抗病毒活性的特异性。
与对照颗粒或游离药物相比，LNPs 上包含 CD4 结合肽可增强所有孵育条件下的抗病毒活性（例如，60 分钟孵育时，EC50=0.12-0.13 对靶向纳米颗粒对游离药物）。CD4-BP4 肽在引发抗病毒活性方面比 CD4-BP2 包被的颗粒效率更高（EC50=7.5 μM 对 15 分钟药物暴露时 >25 μM）。这种增强似乎是由 CD4 的可用性和细胞相关的沙奎那韦浓度驱动的，因为 CD4 的阻断显著削弱了靶向颗粒中的沙奎那韦疗效，而沙奎那韦浓度反映了观察到的抗 HIV 活性。
我们构建了 CD4 靶向 LNPs，为 CD4-HIV 宿主细胞提供了沙奎那韦的选择性结合和有效递药。LNPs 中聚乙二醇的包含将最小化肽的免疫识别。即使在有限的时间暴露下，抗 HIV 效果的增强也是有效的。
