Small Animals Core

摘要-小动物模型核心 小动物模型核心的目标是产生一系列小鼠模型， DH 511谱系的未突变的共同祖先（UCA）或中间抗体（IA）， 中和抗体（bnAb）。这些小鼠模型将用于测试免疫原的功效， 设计用于引出bnAb的DH 511谱系。为此，动物模型核心将产生两种类型 小鼠模型。第一种类型的模型表达DH 511抗体的预先重排的V（D）J外显子。 由于等位基因排斥，预先重排的DH 511 V（D）J外显子将抑制内源性DNA的重排。 小鼠免疫球蛋白（IG）基因座。结果，这些小鼠中的B细胞将主要表达DH 511 抗体的这类小鼠模型的一个常见问题是公差控制机制删除了B 表达敲入的人IG基因的细胞。为了克服这一障碍，我们开发了一种方法， 在成熟B细胞中有条件地表达人抗体，从而避开B细胞过程中的耐受控制， 成熟如有必要，我们将使用该条件表达系统来产生DH 511小鼠模型。 由于这种类型的模型提供了大量表达DH 511 UCA或IA的B细胞群体，因此它将用作 用于免疫原初步评估的灵敏测定法。然而，该系统并没有概括 生理B细胞库在至少两个主要方面的复杂性。第一，独特的UCA表达在 小鼠模型可能不存在于一部分人类群体中。第二，系统缺乏竞争 不相关表位的抗体。为了解决这些限制，动物模型核心将产生第二个 一种小鼠模型，其中DH 511的VH 3 -15、D3-3和JH 6基因片段经历从头V（D）J 重组由于连接多样性，重组将产生宽范围的CDR H3，其中一些是 其可能适合于开发DH 511样抗体。此外，该系统不排除 内源性小鼠IG基因片段的重排。因此，这只小鼠的B细胞库 模型将由潜在的DH 511前体以及其他人VH 3 -15/D3-3/JH 6和小鼠VH 3 -15/D3-3/JH 6组成。 抗体的该小鼠模型的免疫可以评估免疫原选择和免疫应答的能力。 成熟DH 511前体在复杂抗体库中的作用。

Abstract - Small Animal Models Core The objective of the Small Animals Model Core is to generate a series of mouse models that express the unmutated common ancestor (UCA) or intermediate antibodies (IAs) of the DH511 lineage of broadly neutralizing antibody (bnAb). These mouse models will be used to test the efficacy of immunogens that are designed to elicit the DH511 lineage of bnAbs. Toward this end, the Animal Model Core will generate two types of mouse models. The first type of model expresses pre-rearranged V(D)J exons of the DH511 antibodies. Owing to allelic exclusion, the pre-rearranged DH511 V(D)J exon will inhibit the rearrangement of endogenous mouse immunoglobulin (Ig) loci. As a result, B cells in these mice will express predominantly DH511 antibodies. One common problem for this type of mouse model is that tolerance control mechanisms delete B cells expressing the knock-in human Ig genes. To overcome this hurdle, we have developed a method to express human antibodies conditionally in mature B cells, thereby circumventing tolerance control during B cell maturation. If necessary, we will employ this conditional expression system to generate DH511 mouse models. Since this type of model provides a large population of B cells expressing DH511UCA or IAs, it would serve as a sensitive assay for the initial evaluation of immunogens. However, the system does not recapitulate the complexity of physiological B cell repertoire in at least two major respects. First, the unique UCA expressed in the mouse model may not be present in a fraction of human populations. Second, the system lacks competing antibodies for irrelevant epitopes. To address these limitations, the Animal Model Core will generate a second type of mouse model where the VH3-15, D3-3 and JH6 gene segments of DH511 undergo de novo V(D)J recombination. Due to junctional diversity, the recombination will create a wide range of CDR H3s, some of which may be suitable for the development of DH511-like antibodies. Moreover, the system does not preclude the rearrangements of endogenous mouse Ig gene segments. Therefore, the B cell repertoire of this mouse model will consist of potential DH511 precursors as well as other human VH3-15/D3-3/JH6 and mouse antibodies. Immunization of this mouse model could assess the ability of the immunogen to select for and mature DH511 precursors in the context of complex antibody repertoires.