Protective Human Monoclonal Antibodies to HIV1

描述（由申请方提供）：目前可获得的中和HIV原代分离株的人单克隆抗体（mAb）仅针对HIV包膜糖蛋白的少数区域。 一些原代分离株对这些mAb中的许多具有抗性，但可以被来自HIV感染个体的合并血清中和，这表明可能存在尚未鉴定的其他中和表位。 为了开发具有广泛和有效的中和活性的新mAb，其活性将补充先前描述的mAb的活性，其可用于被动免疫，并且其表位可被表征并纳入候选HIV疫苗的设计中，我们提出：（a）产生针对HIV-1原代分离株的具有有效和广泛中和活性的人mAb，其靶向先前未鉴定的表位。 现有的人抗HIV mAb是根据其结合活性选择的。 我们建议根据其功能选择抗HIV mAb，即，它们中和含有各种原代分离物的env基因的假病毒体的能力。 (b)描绘通过中和筛选选择的新mAb的中和活性的宽度。 (c)使用各种免疫学、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mAb所识别的表位。 表位作图技术将包括使用抗原片段文库、随机肽噬菌体展示文库、表位切除/提取和Arg/Lys化学修饰方法以及X射线晶体学分析。 这些研究将阐明最好的中和mAb识别的表位的性质，提供有关诱导保护性Ab的表位结构的关键信息。 这些数据还将阐明mAb互补位的结构、表位和互补位之间的分子间相互作用以及不同HIV毒株之间交叉反应性的分子基础。 (d)使用“聚焦诱变”技术对两种选定的mAb进行工程改造，以提高其效力和广度，随后确定这些工程改造的mAb识别的表位的结构。 这些研究的结果应提供被动免疫的试剂和HIV糖蛋白抗原决定簇的性质的数据，用于设计诱导广泛中和抗体的免疫原。

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.