Department of Molecular Discovery Technologies, Bristol-Myers Squibb, Waltham, Massachusetts, USA.
Department of Virology, Bristol-Myers Squibb, Wallingford, Connecticut, USA.
J Virol. 2018 Jun 29;92(14). doi: 10.1128/JVI.00421-18. Print 2018 Jul 15.
The N17 region of gp41 in HIV-1 is the most conserved region in gp160. mRNA selection technologies were used to identify an adnectin that binds to this region and inhibits gp41-induced membrane fusion. Additional selection conditions were used to optimize the adnectin to greater potency (5.4 ± 2.6 nM) against HIV-1 and improved binding affinity for an N17-containing helical trimer (0.8 ± 0.4 nM). Resistance to this adnectin mapped to a single Glu-to-Arg change within the N17 coding region. The optimized adnectin (6200_A08) exhibited high potency and broad-spectrum activity against 123 envelope proteins and multiple clinical virus isolates, although certain envelope proteins did exhibit reduced susceptibility to 6200_A08 alone. The reduced potency could not be correlated with sequence changes in the target region and was thought to be the result of faster kinetics of fusion mediated by these envelope proteins. Optimized linkage of 6200_A08 with a previously characterized adnectin targeting CD4 produced a highly synergistic molecule, with the potency of the tandem molecule measured at 37 ± 1 pM. In addition, these tandem molecules now exhibited few potency differences against the same panel of envelope proteins with reduced susceptibility to 6200_A08 alone, providing evidence that they did not have intrinsic resistance to 6200_A08 and that coupling 6200_A08 with the anti-CD4 adnectin may provide a higher effective on rate for gp41 target engagement. There continue to be significant unmet medical needs for patients with HIV-1 infection. One way to improve adherence and decrease the likelihood of drug-drug interactions in HIV-1-infected patients is through the development of long-acting biologic inhibitors. This study describes the development and properties of an adnectin molecule that targets the most conserved region of the gp41 protein and inhibits HIV-1 with good potency. Moreover, when fused to a similar adnectin targeted to the human CD4 protein, the receptor for HIV-1, significant synergies in potency and efficacy are observed. These inhibitors are part of an effort to develop a larger biologic molecule that functions as a long-acting self-administered regimen for patients with HIV-1 infection.
HIV-1 中的 gp41 的 N17 区域是 gp160 中最保守的区域。使用 mRNA 选择技术来鉴定与该区域结合并抑制 gp41 诱导的膜融合的连接蛋白。使用附加的选择条件来优化连接蛋白，以获得对 HIV-1 的更大效力（5.4±2.6 nM），并提高与包含 N17 的螺旋三聚体的结合亲和力（0.8±0.4 nM）。对这种连接蛋白的抗性映射到 N17 编码区域内单个 Glu 到 Arg 的变化。优化后的连接蛋白（6200_A08）对 123 种包膜蛋白和多种临床病毒分离株表现出高效力和广谱活性，尽管某些包膜蛋白对 6200_A08 单独显示出降低的敏感性。这种效力降低不能与靶区的序列变化相关联，被认为是由这些包膜蛋白介导的融合更快动力学的结果。通过将 6200_A08 与先前表征的靶向 CD4 的连接蛋白优化连接，产生了一种高度协同的分子，串联分子的效力测量值为 37±1 pM。此外，这些串联分子现在对具有降低的单独对 6200_A08 的敏感性的相同包膜蛋白组表现出很少的效力差异，这提供了证据表明它们对 6200_A08 没有固有抗性，并且将 6200_A08 与抗 CD4 连接蛋白偶联可能为 gp41 靶标结合提供更高的有效结合率。艾滋病毒感染者仍然存在重大的未满足的医疗需求。改善 HIV-1 感染者的依从性并降低药物相互作用可能性的一种方法是开发长效生物抑制剂。本研究描述了针对 gp41 蛋白最保守区域并以良好效力抑制 HIV-1 的连接蛋白分子的开发和特性。此外，当与靶向 HIV-1 受体人类 CD4 蛋白的类似连接蛋白融合时，观察到效力和功效的显著协同作用。这些抑制剂是开发作为长效自我管理方案的更大生物分子的努力的一部分，用于 HIV-1 感染患者。
