IDENTIFICATION OF HIV VACCINE CANDIDATE PEPTIDES BY SCREENING RANDOM PHAGE EPITOPE LIBRARIES
IDENTIFICATION OF HIV VACCINE CANDIDATE PEPTIDES BY SCREENING RANDOM PHAGE EPITOPE LIBRARIES
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DOI：
10.1006/viro.1993.1179
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发表时间：
1993-04-01
期刊：
影响因子：
3.7
通讯作者：
CONLEY, AJ
中科院分区：
文献类型：
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作者：
KELLER, PM;ARNOLD, BA;CONLEY, AJ
在实验性 HIV-1 疫苗研究中用作免疫原的大多数合成 HIV-1 gp120 V3 环肽都是根据天然存在的病毒 gp120 V3 环建模的。在实验动物中，这些免疫原通常会引发类型（或变体）特异性的中和抗体，这些抗体在 HIV-1 变体中不具有广泛反应性。为了寻找 V3 环更通用的结构，我们通过筛选融合噬菌体 15 残基表位库中显示的随机表位，获得了模拟 V3 环序列的候选表位。人单克隆抗体 447-52D 是一种高效且具有广泛反应性的病毒中和抗体，可识别保守的 V3 环尖端基序 GPXR，是探针。通过使用专门为此工作设计的筛选方法，我们鉴定了数百个反应性噬菌体克隆，并对其中 70 个进行了测序。超过 98% 的表位含有 GPXR 基序，但这 70 个表位中没有一个与迄今为止描述的任何 V3 变体环完全相同。其中一个序列被合成为 β-马来酰亚胺丙酰基 15 聚体肽，共价缀合至载体并用于免疫兔子。在所有动物中均获得了高抗肽效价，其中四个个体反应中的三个也与代表“北美共识”V3环的肽结合。这三只阳性兔子的血清在体外中和了 HIV-1 变异体 SF-2。此外，其中一种能够中和变体 AL-1。这两种变体都被认为具有北美共识类型的 V3 环。因此，中和反应是通过使用免疫原获得的，该免疫原因其结合广泛反应性人单克隆抗体的能力而被选择，而不是根据HIV-1 gp120 V3环序列建模。
Most synthetic HIV-1 gp120 V3 loop peptides that are used as immunogens in experimental HIV-1 vaccine studies are modeled from the naturally occurring viral gp120 V3 loops. In experimental animals these immunogens generally elicit type (or variant)-specific neutralizing antibodies that are not broadly reactive among HIV-1 variants. In an attempt to find a more general structure for the V3 loop, we have obtained candidates that mimic V3 loop sequences by screening random epitopes displayed in a fusion phage 15-residue epitope library. Human monoclonal antibody 447-52D, a highly potent and broadly reactive virus-neutralizing antibody that recognizes the conserved V3 loop tip motif GPXR, was the probe. By using a screening method that was designed specifically for this work, we identified hundreds of reactive phage clones, 70 of which were sequenced. Over 98% of the epitopes contain the motif GPXR, yet none of the 70 are an identical match to any V3 variant loop described to date. One of these sequences was synthesized as the β-maleimidopropionyl 15-mer peptide, covalently conjugated to a carrier and used to immunize rabbits. High anti-peptide titers were obtained in all animals with three of four individual responses also binding to a peptide that is representative of the "North American consensus" V3 loop. The sera from these three positive rabbits neutralized HIV-1 variant SF-2in vitro. In addition, one of them was capable of neutralizing variant AL-1. Both of these variants are considered to have V3 loops of the North American consensus type. Thus, neutralizing responses were obtained by use of an immunogen that was selected for its ability to bind a broadly reactive human monoclonal antibody rather than modeled from an HIV-1 gp120 V3 loop sequence.