Identification of a linear peptide recognized by monoclonal antibody 2D7 capable of generating CCR5-Specific antibodies with human immunodeficiency virus-neutralizing activity
Identification of a linear peptide recognized by monoclonal antibody 2D7 capable of generating CCR5-Specific antibodies with human immunodeficiency virus-neutralizing activity
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DOI：
10.1128/jvi.79.11.6791-6800.2005
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发表时间：
2005-06-01
影响因子：
5.4
通讯作者：
Golding, H
中科院分区：
文献类型：
--
作者：
Khurana, S;Kennedy, M;Golding, H
CCR5是人类免疫缺陷病毒(HIV)感染的主要辅助受体。小鼠单抗(NMB)2D7识别CCR5第二细胞外环中的构象依赖表位，是最有效的R5病毒进入细胞的抑制剂之一。然而，到目前为止，将2D7人源化以供体内人类使用的尝试尚未成功。用表达随机多肽的丝状噬菌体文库鉴定单抗2D7识别的多肽模拟表位。一种含有该序列的合成肽(2D7-2SK)，与单抗2D7高亲和力结合并逆转其HIV-1融合抑制活性。该肽包含与人CCR5第二细胞外环的两个末端区域的序列同源性，这两个区域都是单抗2D7结合所必需的。在Biacore生物传感器检测中，兔抗2D7模拟表位抗体与单抗2D7竞争结合2D7-2SK多肽。重要的是，兔抗2D7-2SK抗体与细胞上的CCR5结合，并特异性地抑制R5(而不是X4)包膜介导的合胞体的形成。这些抗体还中和了与单抗2D7类似的R5 HIV分离株对人外周血单个核细胞的感染。综上所述，我们已经发现了一种与CCR5上的单抗2D7表位非常相似的新的多肽。该多肽可作为潜在的候选疫苗或分离出2D7样人抗体作为R5病毒的进入抑制物。
CCR5 is the major coreceptor for human immunodeficiency virus (HIV) infection. The murine monoclonal antibody (NMb) 2D7, which recognizes a conformation-dependent epitope in the second extracellular loop of CCR5, is one of the most potent inhibitors of R5 virus cell entry. However, attempts to humanize 2D7 for in vivo human use have been unsuccessful so far. A filamentous phage library expressing random peptides was used to identify a peptide mimitope that is recognized by MAb 2D7. A synthetic peptide containing this sequence (2D7-2SK) bound to MAb 2D7 with high affinity and reversed its HIV type 1 (HIV-1) fusion inhibitory activity. The peptide contains sequence homologies to two distal regions of the second extracellular loop of human CCR5, both of which are required for MAb 2D7 binding. Rabbit anti-2D7-mimitope antibodies competed with MAb 2D7 for binding to the 2D7-2SK peptide in Biacore biosensor testing. Importantly, the rabbit anti-2D7-2SK antibodies bound to CCR5 on cells and specifically inhibited R5 (but not X4) envelope-mediated syncytium formation. These antibodies also neutralized infection of human peripheral blood mononuclear cells with R5 HIV isolates comparably to MAb 2D7. In summary, we have identified a novel peptide that closely mimics the MAb 2D7 epitope on CCR5. This peptide could be included as a potential vaccine candidate or to isolate 2D7-like human antibodies as entry inhibitors for R5 viruses.