MPER broadly neutralizing antibody knockin mice to study anti-HIV Bcell responses

MPER 广泛中和抗体敲入小鼠用于研究抗 HIV B 细胞反应

基本信息

批准号：
8054244
负责人：
Laurent Karl Verkoczy
金额：
$ 38.61万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2015-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8054244
关键词：
Acquired Immunodeficiency Syndrome Affinity Anti-Retroviral Agents Antibodies Antibody Formation Antigens Autoantigens B cell repertoire B-Cell Development B-Lymphocytes Back Binding Bone Marrow Charge DNA Sequence Rearrangement Defect Developing Countries Development Engineering Epitopes Exhibits Gene Targeting Goals HIV HIV Envelope Protein gp120 HIV-1 Heavy-Chain Immunoglobulins Human Immune response Immunization Immunoglobulin Variable Region In Vitro Individual Infection Knock-in Mouse Light Modeling Modification Monoclonal Antibodies Mouse Strains Mus Mutate Mutation Patients Peripheral Pharmaceutical Preparations Polysaccharides Population Process Production Regulation Relative (related person)Role Self Tolerance Series Shapes Structural Genes Structure Testing Vaccination Vaccines anergy arm autoreactivity base central tolerance design genetic immunization strategies in vivo neutralizing antibody novel novel strategies pandemic disease prevent prophylactic public health relevance receptor research study response simian human immunodeficiency virus

项目摘要

DESCRIPTION (provided by applicant): The identification of a few rarely made antibodies to different HIV-1 envelope epitopes which are capable of neutralizing a broad range of HIV-1 isolates in vitro and controlling SHIV infection in vivo has provided hope for achieving an antibody-based HIV-1 vaccine strategy. One of these rare antibodies, 2F5, has particularly potent and broad neutralizing activity and is directed against an attractive antibody-based vaccine target, the MPER epitope of the HIV-1 gp41 region. 2F5 has unusually long charged CDR3s and exhibits polyreactivity, raising the possibility that antibodies like 2F5 cannot be elicited because the B cells from which they originate have reactivity with host antigens. Using a gene-targeting approach, we have generated mice (2F5 VH) with directed expression of the original 2F5 heavy chain (HC) variable region into the mouse HC locus, and made the important observation that 2F5 HC-expressing B cells are primarily deleted in the bone marrow at the pre-B to immature transition. Despite this profound defect, a small, but detactable population of B cells are present in the periphery which retain the 2F5 HC. In this application, we propose to comprehensively extend our characterization of 2F5 VH mice, first to test the hypothesis that most of their remaining peripheral B cells have lost autoreactivity, either by LC editing, anergy or modification of the 2F5 HC. Using a systematic array of genetic, immunization, and pharmacological approaches to modulate self-tolerance, we will then test the hypothesis that these mice can be pushed into producing high titers of broadly neutralizing antibodies. Finally, we will extend/refine our studies in 2F5 VH mice by using a series of "back-mutated" 2F5 VH mice (expressing 2F5 VH regions that are either germline or have different selected back-mutations), to examine the ability of the 2F5 precursor B cell repertoire, when shaped by immunization-driven affinity maturation, to generate "2F5-like" neutralizing antibodies. PUBLIC HEALTH RELEVANCE: The development of a protective antibody-based HIV-1 vaccine remains an enormous challenge. In this study, we propose to use a series of mouse strains we have engineered to express different versions of the broadly and potently neutralizing HIV-1 antibody 2F5 in order to: 1) determine how the processes of self-tolerance and affinity maturation impact the ability of B cells to make neutralizing antibodies, and 2) to examine if appropriate manipulation of these processes can elicit B cells to make such antibodies. These experiments should be helpful in formulating novel strategies for properly eliciting protective HIV-1 antibodies in patients.

描述（由申请人提供）：鉴定了一些针对不同 HIV-1 包膜表位的罕见抗体，这些抗体能够在体外中和多种 HIV-1 分离株并在体内控制 SHIV 感染，这为实现抗体提供了希望。基于 HIV-1 的疫苗策略。其中一种罕见抗体 2F5 具有特别有效和广泛的中和活性，并且针对有吸引力的基于抗体的疫苗靶点，即 HIV-1 gp41 区域的 MPER 表位。 2F5 具有异常长的带电荷 CDR3 并表现出多反应性，这增加了无法引发像 2F5 这样的抗体的可能性，因为它们所源自的 B 细胞与宿主抗原具有反应性。使用基因靶向方法，我们生成了将原始 2F5 重链 (HC) 可变区定向表达到小鼠 HC 基因座中的小鼠 (2F5 VH)，并观察到表达 2F5 HC 的 B 细胞主要被删除。在骨髓中处于预B向未成熟的转变。尽管存在这种严重缺陷，但在保留 2F5 HC 的外周中仍存在少量但可检测的 B 细胞群。在此应用中，我们建议全面扩展我们对 2F5 VH 小鼠的表征，首先通过 LC 编辑、无反应性或 2F5 HC 的修饰来测试其大部分剩余外周 B 细胞已失去自身反应性的假设。然后，我们将使用一系列系统的遗传、免疫和药理学方法来调节自我耐受性，然后测试这些小鼠可以产生高滴度的广泛中和抗体的假设。最后，我们将通过使用一系列“回复突变”2F5 VH 小鼠（表达种系或具有不同选择回复突变的 2F5 VH 区域）来扩展/完善我们在 2F5 VH 小鼠中的研究，以检查2F5 前体 B 细胞库通过免疫驱动的亲和力成熟形成时，可产生“2F5 样”中和抗体。公共卫生相关性：基于抗体的保护性 HIV-1 疫苗的开发仍然是一个巨大的挑战。在这项研究中，我们建议使用一系列我们设计的小鼠品系来表达不同版本的广泛有效中和 HIV-1 抗体 2F5，以便：1) 确定自我耐受和亲和力成熟的过程如何影响B 细胞产生中和抗体的能力，2) 检查这些过程的适当操作是否可以引发 B 细胞产生此类抗体。这些实验应该有助于制定新策略，在患者体内正确引发保护性 HIV-1 抗体。