Protective Human Monoclonal Antibodies to HIV1

描述（由申请人提供）：目前可用的人单克隆抗体（mab）可以中和HIV初级分离株，仅针对HIV包膜糖蛋白的少数区域。一些初级分离株对这些单克隆抗体具有耐药性，但可以被来自hiv感染者的混合血清中和，这表明可能存在尚未确定的额外中和表位。为了开发具有广泛和广泛中和活性的新单克隆抗体，其活性将补充先前描述的单克隆抗体，这些单克隆抗体可用于被动免疫，其表位可被表征并纳入候选HIV疫苗的设计，我们建议：(a)生产针对先前未识别的表位的HIV-1初级分离株具有有效和广泛中和活性的人单克隆抗体。现有的人类抗hiv单克隆抗体是根据其结合活性来选择的。我们建议根据它们的功能来选择抗hiv单抗，即它们能够中和含有各种初级分离株env基因的假病毒粒子。(b)描绘用中和筛选筛选出的新单克隆抗体的中和活性宽度。(c)利用各种免疫学、生物化学、分子和物理技术来鉴定和表征最广泛和最有效的单克隆抗体识别的表位。表位定位技术将包括抗原片段文库、随机肽噬菌体展示文库、表位切除/提取和精氨酸/赖氨酸化学修饰方法以及x射线晶体学分析。这些研究将阐明最佳中和单抗识别的表位的性质，提供诱导保护性单抗的表位结构的关键信息。这些数据还将阐明单抗旁位的结构，表位和旁位之间的分子间相互作用，以及不同HIV毒株之间交叉反应的分子基础。(d)利用“聚焦诱变”技术对两个选定的单克隆抗体进行基因工程改造，以提高其效力和宽度，随后确定这些基因工程单克隆抗体识别的表位结构。这些研究的结果将为被动免疫提供试剂和HIV糖蛋白抗原决定因子的性质提供数据，这对设计可诱导广泛中和抗体的免疫原有用。

DESCRIPTION (provided by applicant): Currently available human monoclonal antibodies (mAbs) which neutralize primary isolates of HIV are directed against only a few regions of the HIV envelope glycoproteins. Some primary isolates are resistant to many of these mAbs but can be neutralized by pooled sera from HIV-infected individuals, suggesting that there may be additional neutralizing epitopes which have not yet been identified. To develop new mAbs with broad and potent neutralizing activity whose activity will complement those of previously described mAbs, which can be used for passive immunization, and whose epitopes can be characterized and incorporated into the design of candidate HIV vaccines, we propose to: (a) Produce human mAbs with potent and broad neutralizing activity against HIV-1 primary isolates that target previously unidentified epitopes. Existing human anti-HIV mAbs have been selected on the basis of their binding activity. We propose to select anti-HIV mAbs based on their function, i.e., their ability to neutralize pseudovirions containing env genes of various primary isolates. (b) Delineate the breadth of the neutralizing activity of the new mAbs selected with the neutralization screen. (c) Use a variety of immunologic, biochemical, molecular and physical techniques to identify and characterize the epitopes recognized by the broadest and most potent of the mAbs. Epitope mapping techniques will include the use of an antigen fragment library, random peptide phage display libraries, epitope excision/extraction and Arg/Lys chemical modification methods, and X-ray crystallographic analyses. These studies will elucidate the nature of the epitopes recognized by the best of the neutralizing mAbs, providing critical information about the structure of epitopes that induce protective Abs. These data will also elucidate the structure of the mAb paratopes, the intermolecular interactions between epitopes and paratopes, and the molecular basis for the cross-reactivity between diverse strains of HIV. (d) Use a "focused mutagenesis" technique to engineer two selected mAbs in order to improve their potency and breadth, and subsequently determine the structure of the epitopes recognized by these engineered mAbs. The results of these studies should provide both reagents for passive immunization and data on the nature of antigenic determinants of HIV glycoproteins useful for designing immunogens that will induce broadly neutralizing Abs.