State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing.
Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China.
AIDS. 2018 Aug 24;32(13):1749-1761. doi: 10.1097/QAD.0000000000001869.
Current treatments cannot completely eradicate HIV-1 owing to the presence of latently infected cells, which harbor transcriptionally silent HIV-1. However, defucosylated antibodies can readily kill latently infected cells after their activation to express envelope glycoprotein (Env) through antibody-dependent cellular cytotoxicity (ADCC). We herein aimed to test a defucosylated bispecific multivalent molecule consisting of domain-antibody and single-domain CD4, LSEVh-LS-F, for its HIV-1 neutralizing activity and ADCC against the reactivated latently infected cells, compared with the nondefucosylated molecule LSEVh-LS.
LSEVh-LS-F's neutralizing activity against a panel of newly characterized Chinese HIV-1 clinical isolates was assessed by using TZM-bl-based and PBMC-based assays. LSEVh-LS-F-mediated ADCC in the presence of natural killer cells against cell lines that stably express Env proteins, HIV-1-infected cells and LRA-reactivated HIV-1 latent cells, was measured using a lactate dehydrogenase (LDH) cytotoxicity assay or flow cytometry.
LSEVh-LS-F and LSEVh-LS were equally effective in neutralized infection of all HIV-1 isolates tested with IC50 and IC90 values 3∼4-fold lower than those of VRC01. LSEVh-LS-F was more effective in natural killer-mediated killing of HIV-1 Env-expressing cell lines, HIV-1-infected cells, latency reactivation agents-reactivated ACH2 cells and reactivated latently infected resting CD4+ T cell line as well as resting CD4+ T lymphocytes isolated from patients receiving HAART.
LSEVh-LS-F exhibits broad HIV-1 neutralizing activity and enhanced ADCC against HIV-1-infected cells, reactivated latently infected cell lines and primary CD4+ T cells, thus being a promising candidate therapeutic for eradicating the HIV-1 reservoir.
由于潜伏感染细胞的存在，目前的治疗方法无法完全清除 HIV-1，这些细胞中含有转录沉默的 HIV-1。然而，去岩藻糖基化抗体可以通过抗体依赖性细胞毒性（ADCC）在激活后轻易杀死潜伏感染的细胞，从而表达包膜糖蛋白（Env）。本研究旨在测试一种由域抗体和单域 CD4 组成的去岩藻糖基化双特异性多价分子 LSEVh-LS-F，以评估其对新鉴定的中国 HIV-1 临床分离株的中和活性和对再激活潜伏感染细胞的 ADCC，与非去岩藻糖基化分子 LSEVh-LS 进行比较。
使用 TZM-bl 基于和 PBMC 基于的测定法评估 LSEVh-LS-F 对一组新鉴定的中国 HIV-1 临床分离株的中和活性。使用乳酸脱氢酶（LDH）细胞毒性测定法或流式细胞术，在自然杀伤细胞存在的情况下，测量 LSEVh-LS-F 在表达 Env 蛋白的细胞系、HIV-1 感染细胞和 LRA 再激活的 HIV-1 潜伏细胞中对 ADCC 的介导作用。
LSEVh-LS-F 和 LSEVh-LS 在中和所有测试的 HIV-1 分离株的感染方面同样有效，IC50 和 IC90 值比 VRC01 低 3∼4 倍。LSEVh-LS-F 更有效地介导自然杀伤细胞对 HIV-1 Env 表达细胞系、HIV-1 感染细胞、潜伏再激活剂再激活的 ACH2 细胞以及再激活的潜伏感染静止 CD4+T 细胞系和从接受 HAART 的患者中分离出的静止 CD4+T 淋巴细胞的杀伤作用。
LSEVh-LS-F 具有广泛的 HIV-1 中和活性和增强的对 HIV-1 感染细胞、再激活潜伏感染细胞系和原代 CD4+T 细胞的 ADCC，因此是一种有前途的清除 HIV-1 储存库的治疗候选物。
