Small Animals Core

小动物核心

• 批准号: 10132976
• 负责人: S. Munir ALAM
• 金额: $ 25万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-09 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10132976
• 关键词: Address; Affinity; Alleles; Animal Model; Animals; Antibodies; Antibody Repertoire; Antigens; B cell repertoire; B-Lymphocytes; Biological Assay; Boston; Bypass; Cell Compartmentation; Cell Maturation; Complex; Development; Distal; Epitopes; Evaluation; Evolution; Exclusion; Exons; Genes; Genetic Recombination; HIV; HIV-1; Human; Immunization; Immunize; Immunoglobulin Genes; Immunoglobulins; In Vitro; Individual; Knock-in; Lead; Light; Mature B-Lymphocyte; Membrane; Methods; Modeling; Mus; Nucleotides; Pediatric Hospitals; Physiological; Population; Research; Research Personnel; Scheme; Series; Source; Specificity; System; Testing; V(D)J Recombination; central tolerance; design; efficacy testing; env Gene Products; experience; experimental study; falls; immunogenic; in vivo; mouse model; neutralizing antibody; programs; screening

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.

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 DH511 谱系的未突变共同祖先 (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 旨在引发 bnAb 的 DH511 谱系。为此，动物模型核心将生成两种类型 鼠标模型。第一种模型表达 DH511 抗体的预重排 V(D)J 外显子。 由于等位基因排斥，预重排的 DH511 V(D)J 外显子将抑制内源性基因的重排。 小鼠免疫球蛋白 (Ig) 位点。因此，这些小鼠的 B 细胞将主要表达 DH511 抗体。此类小鼠模型的一个常见问题是容差控制机制删除了 B 表达敲入人类 Ig 基因的细胞。为了克服这个障碍，我们开发了一种方法 在成熟 B 细胞中有条件地表达人类抗体，从而规避 B 细胞期间的耐受控制 成熟。如有必要，我们将利用该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，因此它可以作为 用于初步评估免疫原的灵敏测定法。然而，系统并没有重述 生理 B 细胞库的复杂性至少在两个主要方面。首先，独特的UCA表达为 小鼠模型可能不存在于一小部分人群中。二是制度缺乏竞争性 针对不相关表位的抗体。为了解决这些限制，动物模型核心将生成第二个 DH511 的 VH3-15、D3-3 和 JH6 基因片段经历从头 V(D)J 的小鼠模型类型 重组。由于连接多样性，重组将产生广泛的 CDR H3，其中一些 这可能适合DH511样抗体的开发。此外，系统并不排除 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 DH511 前体以及其他人类 VH3-15/D3-3/JH6 和小鼠组成 抗体。该小鼠模型的免疫可以评估免疫原选择和 复杂抗体库背景下的成熟 DH511 前体。