Study of broadly neutralizing antibody generation to HIV gp140 in humanized mice

人源化小鼠体内 HIV gp140 广泛中和抗体生成的研究

• 批准号: 8080503
• 负责人: Wayne A. Marasco
• 金额: $ 15.91万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8080503
• 关键词: AIDS/HIV problem; Amino Acids; Animal Model; Animals; Antibodies; Antibody Formation; Antigens; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autologous; B-Lymphocytes; Binding; Biological Assay; Biological Models; CD19 gene; CD34 gene; Cell Ontogeny; Cells; Characteristics; Charge; Cloning; Data; Defect; Development; Engraftment; Failure; Fetal Liver; Generations; Genes; Genetic; Goals; HIV; HIV Envelope Protein gp120; HIV Infections; HIV immunization; HIV vaccine; HIV-1; Hematopoietic stem cells; Human; Immune response; Immune system; Immunization; Immunoglobulin Class Switching; Immunoglobulin G; Immunoglobulin M; Immunoglobulin-Secreting Cells; In Vitro; Individual; Infection; Length; Longevity; Longitudinal Studies; Lymphoid; Lymphoid Cell; Lymphoma; Mediating; Modeling; Molecular; Molecular Profiling; Mus; Plasma Cells; Process; Production; Property; Recombinants; Reporting; Research; Sequence Analysis; Sorting - Cell Movement; Source; System; T-Lymphocyte; Testing; Thymus Gland; Tissues; Transplantation; Umbilical Cord Blood; Vaccination; Vaccine Design; Vaccine Research; Vaccines; Viral Antibodies; Viral Antigens; Virus; antigen binding; cofactor; cytokine; design; experience; expression cloning; genetic analysis; mouse model; neutralizing antibody; public health relevance; response

DESCRIPTION (provided by applicant): The ability to elicit Abs with broad neutralization activity against HIV-1 has been a long sought-after but elusive goal of HIV/AIDS vaccine research. The long-term goal of this proposal is to understand how broad-spectrum neutralizing antibodies (BnAbs) are generated. The majority of the rare BnAbs (2F5, 4E10 and b12) isolated from HIV-1-infected individuals have the common characteristics of long IGHV-CDR3s with positively charged amino acids, structural features often seen in autoantibodies. The main hypothesis to be tested in this proposal is that natural induction of such autoreactive antibodies may be curtailed by the checkpoint control mechanisms occurring during B cell ontogeny. Therefore, a system that models a human immune system, is responsive to HIV infection/immunization and has demonstratable defects in B cell checkpoint control processes is an attractive platform to test this hypothesis. The humanized BLT and GTL mouse models are generated by transplantation of 3-irradiated NOD/scid and NOD/scid IL2r?-/- mice, respectively, with fetal liver and thymus tissues in addition to autologous CD34+ HSCs. The humanized mice allow efficient engraftment of multi-lineage human hemato-lymphoid cells, support a productive HIV-1 infection, develop Ab responses upon immunization with recombinant HIV gp140 trimer and demonstrate autoimmune properties. We will test the ability of these mice to generate strain-specific nAb and BnAbs against HIV-1 upon optimized immunization with gp140 Env trimers. Towards these goals, the specific aims of this proposal are: 1) To test several approaches including the addition of human cytokines and/or activated T cells to induce optimal antigen-dependent class Ig switching and a predominant IgG response in the HIVgp140 immunized BLT and GTL models. 2) To interrogate whether neutralizing antibodies are generated as a result of optimized immunization by HIV pseudotyped virus microneutralization assays. 3) To characterize and quantitate the quality of the neutralizing antibody (nAb) response by cloning and expressing anti-HIV Envelope (Env) Abs isolated by FACS sorting of gp140-trimer binding single B cells from B1-like, conventional B (B2) and Ab secreting cell (ASC)/plasma cell subpopulations. Sequence analysis and binding/neutralization studies of Abs derived from gp140-trimer binding B cell clones will provide a detailed molecular signature of BnAbs. Overall, our studies are aimed at developing a new small animal model to understand the long-standing question of how BnAbs are generated and to set the groundwork for vaccine studies that will result in generation of such BnAb responses. PUBLIC HEALTH RELEVANCE: A major reason for the failure of HIV vaccines is the lack of induction of broadly neutralizing anti-viral antibodies in the host. We propose to utilize new humanized mouse models to study the mechanism(s) by which BnAbs are produced and the barriers that must still be breached to elicit these types of antibodies by vaccination. The results of our studies will establish a new small animal HIV vaccine model and set the groundwork for vaccine studies aimed at the generation of potent and broadly neutralizing antibody responses to HIV.

描述（由申请人提供）： 能够引发对 HIV-1 具有广泛中和活性的抗体的能力一直是 HIV/AIDS 疫苗研究长期追求但难以捉摸的目标。该提案的长期目标是了解广谱中和抗体（BnAb）是如何产生的。从 HIV-1 感染者中分离出来的大多数罕见 BnAb（2F5、4E10 和 b12）具有长 IGHV-CDR3 的共同特征，其中带有带正电荷的氨基酸，这是自身抗体中常见的结构特征。该提案要测试的主要假设是，此类自身反应性抗体的自然诱导可能会受到 B 细胞个体发育过程中发生的检查点控制机制的限制。因此，模拟人类免疫系统、对 HIV 感染/免疫有反应并且在 B 细胞检查点控制过程中具有明显缺陷的系统是检验这一假设的一个有吸引力的平台。人源化 BLT 和 GTL 小鼠模型是通过分别移植 3 次照射的 NOD/scid 和 NOD/scid IL2rα-/- 小鼠而产生的，除了自体 CD34+ HSC 外，还移植有胎儿肝脏和胸腺组织。人源化小鼠可以有效植入多谱系人类血淋巴细胞，支持有效的 HIV-1 感染，在用重组 HIV gp140 三聚体免疫时产生抗体反应，并表现出自身免疫特性。我们将测试这些小鼠在使用 gp140 Env 三聚体进行优化免疫后产生针对 HIV-1 的毒株特异性 nAb 和 BnAb 的能力。为了实现这些目标，本提案的具体目标是：1) 测试几种方法，包括添加人类细胞因子和/或活化的 T 细胞，以诱导最佳的抗原依赖性 Ig 类转换和 HIVgp140 免疫 BLT 中的主要 IgG 反应， GTL 型号。 2) 通过 HIV 假型病毒微中和测定来询问中和抗体是否是由于优化免疫而产生的。 3) 通过克隆和表达抗 HIV 包膜 (Env) Ab，通过 FACS 分选来自 B1 样常规 B (B2) 的 gp140-三聚体结合单个 B 细胞来表征和定量中和抗体 (nAb) 反应的质量。和抗体分泌细胞（ASC）/浆细胞亚群。对来自 gp140-三聚体结合 B 细胞克隆的抗体进行序列分析和结合/中和研究将提供 BnAb 的详细分子特征。总体而言，我们的研究旨在开发一种新的小动物模型，以了解 BnAb 如何产生这一长期存在的问题，并为产生此类 BnAb 反应的疫苗研究奠定基础。 公共卫生相关性：HIV 疫苗失败的一个主要原因是宿主体内缺乏广泛中和抗病毒抗体的诱导。我们建议利用新的人源化小鼠模型来研究 BnAb 的产生机制，以及通过疫苗接种引发这些类型的抗体必须突破的障碍。我们的研究结果将建立一种新的小动物艾滋病毒疫苗模型，并为疫苗研究奠定基础，旨在产生针对艾滋病毒的有效且广泛中和的抗体反应。