Enhanced Exposure of Human Immunodeficiency Virus Type 1 Primary Isolate Neutralization Epitopes through Binding of CD4 Mimetic Compounds
Enhanced Exposure of Human Immunodeficiency Virus Type 1 Primary Isolate Neutralization Epitopes through Binding of CD4 Mimetic Compounds
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DOI：
10.1128/jvi.00227-10
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发表时间：
2010-08-01
影响因子：
5.4
通讯作者：
Matsushita, Shuzo
中科院分区：
文献类型：
--
作者：
Yoshimura, Kazuhisa;Harada, Shigeyoshi;Matsushita, Shuzo
N-（4-氯苯基）-N '-（2，2，6，6-四甲基-哌啶-4-基）-N-二甲酰胺（NBD-556）是一种低分子量化合物，据报道可阻断人类免疫缺陷病毒1型（HIV-1）gp 120与其受体CD 4之间的相互作用。通过比较单个单克隆抗体与表达Env的细胞表面的结合特征，我们研究了抗gp 120单克隆抗体（MAbs）与NBD-556对Env蛋白结合的增强作用是否与可溶性CD 4（sCD 4）相似。在流式细胞术分析中，抗CD 4诱导表位（CD 4 i）单克隆抗体对NBD-556预处理的Env表达细胞表面的结合特征与对sCD 4预处理的细胞表面的结合特征相似。为了研究NBD-556在gp 120上的结合位置，我们在体外诱导了对NBD-556和sCD 4具有抗性的HIV-1变体。在存在50 μ M NBD-556的情况下，在第21代，鉴定出两个氨基酸取代（C3中的S375 N和C4中的A433 T）。另一方面，在用sCD 4进行的选择中，在传代过程中出现了7个突变（E211 G、P212 L、V255 E、N280 K、S375 N、G380 R和G431 E）。用NBD-556和sCD 4选择后的突变谱在其三维位置上非常相似。此外，NBD-556与抗gp 120单克隆抗体的组合显示出针对HIV-1的高度协同相互作用。我们进一步发现，通过添加NBD-556增强中和活性后，同期病毒对患者血浆中的抗体变得高度敏感。这些发现表明，小分子化合物如NBD可以增强体内CD 4 i和抗V3抗体的中和活性。
N-(4-Chlorophenyl)-N'-(2,2,6,6-tetramethyl-piperidin-4-yl)-oxalamide (NBD-556) is a low-molecular-weight compound that reportedly blocks the interaction between human immunodeficiency virus type 1 (HIV-1) gp120 and its receptor CD4. We investigated whether the enhancement of binding of anti-gp120 monoclonal antibodies (MAbs) toward envelope (Env) protein with NBD-556 are similar to those of soluble CD4 (sCD4) by comparing the binding profiles of the individual MAbs to Env-expressing cell surfaces. In flow cytometric analyses, the binding profiles of anti-CD4-induced epitope (CD4i) MAbs toward NBD-556-pretreated Env-expressing cell surfaces were similar to the binding profiles toward sCD4-pretreated cell surfaces. To investigate the binding position of NBD-556 on gp120, we induced HIV-1 variants that were resistant to NBD-556 and sCD4 in vitro. At passage 21 in the presence of 50 mu M NBD-556, two amino acid substitutions (S375N in C3 and A433T in C4) were identified. On the other hand, in the selection with sCD4, seven mutations (E211G, P212L, V255E, N280K, S375N, G380R, and G431E) appeared during the passages. The profiles of the mutations after the selections with NBD-556 and sCD4 were very similar in their three-dimensional positions. Moreover, combinations of NBD-556 with anti-gp120 MAbs showed highly synergistic interactions against HIV-1. We further found that after enhancing the neutralizing activity by adding NBD-556, the contemporaneous virus became highly sensitive to antibodies in the patient's plasma. These findings suggest that small compounds such as NBDs may enhance the neutralizing activities of CD4i and anti-V3 antibodies in vivo.