近日，来自美国NIH的科学家们在国际学术期刊上发表了一项最新研究进展，他们报告称注射一种叫做VRC01的强效抗体就能够抑制未接受抗逆转录病毒治疗的HIV携带者血液中的HIV病毒水平。研究人员还发现通过静脉注射或皮下注射方式将VRC01抗体注入病毒携带者体内具有非常好的安全性和耐受性，并且注入的抗体能够在病人血液中保持较长时间。
科学家们领导的I期临床试验共包括23名HIV携带者，其中有15人接受了抗逆转录病毒治疗，另外8人没有接受治疗。研究人员对接受治疗的HIV病毒携带者进行了两次抗体注射，而没有接受抗逆转录病毒治疗的携带者只接受了一次抗体注射，随后研究人员对抗体注射的安全性以及能否降低血浆中以及血细胞中的病毒载量进行了评估。
研究人员发现虽然抗体注射并没有减少血细胞中的HIV数量，但没有接受抗逆转录病毒治疗的8人中有6人血浆中的病毒载量下降了超过10倍，病毒载量下降的病人中有两人在研究刚开始的时候携带病毒量最少，而注射抗体之后，HIV病毒在抗体维持有效浓度的接近3周内被抑制在极低水平，其余4人的病毒载量大幅度下降，但并没有下降到无法检测的水平。而经过检测发现接受抗体治疗但病毒载量没有发生变化的另外两人其体内携带的HIV病毒类型能够对VRC01抗体产生抵抗。那些已经接受了抗逆转录病毒治疗的病人其体内HIV病毒已经受到抑制，接受抗体注射并没有表现出任何其他作用。
研究人员表示，其他几个正在进行的临床研究将会进一步阐释HIV抗体在治疗或预防HIV感染方面所发挥的潜在作用。
DOI: 10.1126/scitranslmed.aad5752
Virologic effects of broadly neutralizing antibody VRC01 administration during chronic HIV-1 infection
Passive immunization with HIV-1-neutralizing monoclonal antibodies (mAbs) is being considered for prevention and treatment of HIV-1 infection. As therapeutic agents, mAbs could be used to suppress active virus replication, maintain suppression induced by antiretroviral therapy (ART), and/or decrease the size of the persistent virus reservoir. We assessed the impact of VRC01, a potent human mAb targeting the HIV-1 CD4 binding site, on ART-treated and untreated HIV-1-infected subjects. Among six ART-treated individuals with undetectable plasma viremia, two infusions of VRC01 did not reduce the peripheral blood cell-associated virus reservoir measured 4 weeks after the second infusion. In contrast, six of eight ART-untreated, viremic subjects infused with a single dose of VRC01 experienced a 1.1 to 1.8 log10 reduction in plasma viremia. The two subjects with minimal responses to VRC01 were found to have predominantly VRC01-resistant virus before treatment.
Notably, two subjects with plasma virus load <1000 copies/ml demonstrated virus suppression to undetectable levels for over 20 days until VRC01 levels declined. Among the remaining four subjects with baseline virus loads between 3000 and 30,000 copies, viremia was only partially suppressed by mAb infusion, and we observed strong selection pressure for the outgrowth of less neutralization-sensitive viruses. In summary, a single infusion of mAb VRC01 significantly decreased plasma viremia and preferentially suppressed neutralization-sensitive virus strains. These data demonstrate the virological effect of this neutralizing antibody and highlight the need for combination strategies to maintain virus suppression.