Small Animals Core

摘要-小动物模型核心 小动物模型核心的目标是生成一系列表达 广泛性血友病DH511谱系的未突变的共同祖先(UCA)或中间抗体(IAS) 中和抗体(BNab)。这些小鼠模型将被用来测试免疫原的有效性，这些免疫原 旨在诱导BNAb的DH511谱系。为此，Animal Model Core将生成两种类型 老鼠模型。第一类模型表达预先重排的DH511抗体V(D)J外显子。 由于等位基因排斥，预先重排的DH511 V(D)J外显子会抑制内源基因的重排。 小鼠免疫球蛋白(Ig)基因座。因此，这些小鼠中的B细胞将主要表达DH511 抗体。这种类型的鼠标模型的一个常见问题是，耐受控制机制删除了B 表达敲入的人类免疫球蛋白基因的细胞。为了克服这一障碍，我们开发了一种方法来 在成熟的B细胞中有条件地表达人类抗体，从而绕过B细胞期间的耐受控制 成熟。如果有必要，我们将使用这个条件表达系统来生成DH511小鼠模型。 由于这种类型的模型提供了大量表达DH511UCA或IAS的B细胞，因此它将作为 一种对免疫原进行初步评估的灵敏的分析方法。但是，该系统并不概括 生理B细胞谱系的复杂性至少在两个主要方面。首先，唯一的UCA在 老鼠模型可能不会出现在一小部分人类群体中。其次，该体系缺乏竞争性 不相关表位的抗体。为了解决这些限制，Animal Model Core将生成第二个 DH511的VH3-15、D3-3和JH6基因片段经历V(D)J重生的小鼠模型类型 重组。由于连接的多样性，重组将产生广泛的CDR H3，其中一些 为DH511类抗体的研制奠定了基础。此外，该系统并不排除 内源性小鼠免疫球蛋白基因片段重排。因此，这只小鼠的B细胞库 模型将由潜在的DH511前体以及其他人VH3-15/D3-3/JH6和小鼠组成 抗体。这种小鼠模型的免疫可以评估免疫原选择和 在复杂抗体谱系背景下的成熟DH511前体。

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.