HbAHP-25, an In-Silico Designed Peptide, Inhibits HIV-1 Entry by Blocking gp120 Binding to CD4 Receptor

Human Immunodeficiency Virus (HIV-1) poses a serious threat to the developing world and sexual transmission continues to be the major source of new infections. Therefore, the development of molecules, which prevent new HIV-1 infections, is highly warranted. In the present study, a panel of human hemoglobin (Hb)-α subunit derived peptides and their analogues, with an ability to bind gp120, were designed in-silico and their anti-HIV-1 activity was evaluated. Of these peptides, HbAHP-25, an analogue of Hb-α derived peptide, demonstrated significant anti-HIV-1 activity. HbAHP-25 was found to be active against CCR5-tropic HIV-1 strains (ADA5 and BaL) and CXCR4-tropic HIV-1 strains (IIIB and NL4-3). Surface plasmon resonance (SPR) and ELISA revealed direct interaction between HbAHP-25 and HIV-1 envelope protein, gp120. The peptide prevented binding of CD4 to gp120 and blocked subsequent steps leading to entry and/or fusion or both. Anti-HIV activity of HbAHP-25 appeared to be specific as it failed to inhibit the entry of HIV-1 pseudotyped virus (HIV-1 VSV). Further, HbAHP-25 was found to be non-cytotoxic to TZM-bl cells, VK2/E6E7 cells, CEM-GFP cells and PBMCs, even at higher concentrations. Moreover, HbAHP-25 retained its anti-HIV activity in presence of seminal plasma and vaginal fluid. In brief, the study identified HbAHP-25, a novel anti-HIV peptide, which directly interacts with gp120 and thus has a potential to inhibit early stages of HIV-1 infection.人类免疫缺陷病毒1型（Human Immunodeficiency Virus, HIV-1）对发展中国家构成严重威胁，性传播仍是新发感染的主要途径。因此，研发可预防HIV-1新发感染的分子极具必要性。本研究经计算机虚拟设计了一组能够结合gp120的人血红蛋白（Hb）α亚基衍生肽及其类似物，并对其抗HIV-1活性进行了评估。在上述肽类中，Hb-α衍生肽类似物HbAHP-25展现出显著的抗HIV-1活性。研究发现，HbAHP-25对嗜CCR5型HIV-1毒株（ADA5与BaL）以及嗜CXCR4型HIV-1毒株（IIIB与NL4-3）均具有抗病毒活性。表面等离子体共振（Surface Plasmon Resonance, SPR）与酶联免疫吸附试验（Enzyme-Linked Immunosorbent Assay, ELISA）结果证实，HbAHP-25可与HIV-1包膜蛋白gp120发生直接相互作用。该肽可阻断CD4与gp120的结合，并抑制后续病毒侵入和/或融合（或二者兼具）的相关步骤。HbAHP-25的抗HIV活性具有特异性，其无法抑制HIV-1水泡性口炎病毒假型病毒（HIV-1 VSV）的侵入。进一步实验表明，即便在高浓度下，HbAHP-25对TZM-bl细胞、VK2/E6E7细胞、CEM-GFP细胞以及外周血单个核细胞（PBMCs）均无细胞毒性。此外，在精浆与阴道液环境中，HbAHP-25仍可维持其抗HIV活性。总而言之，本研究鉴定出HbAHP-25这一新型抗HIV肽，其可直接与gp120结合，因而具备抑制HIV-1感染早期阶段的潜力。