Project 2: Affinity Maturation of the B-cell Repertoire

项目 2：B 细胞库的亲和力成熟

• 批准号: 10549612
• 负责人: GARNETT H KELSOE
• 金额: $ 36.54万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10549612
• 关键词: Affinity; Antibodies; Antibody Affinity; Antibody Response; Antigen Receptors; Antigens; B cell repertoire; B-Lymphocytes; Biology; Bone Marrow; Cells; Collaborations; Contralateral; Distal; Evolution; Gene Rearrangement; Genetic; Helper-Inducer T-Lymphocyte; Hemagglutinin; Herd Immunity; Immunity; Immunization; Immunize; Immunologic Memory; Infection; Influenza; Influenza Hemagglutinin; Influenza vaccination; Ipsilateral; Label; Location; Lymphoid Tissue; Memory B-Lymphocyte; Minority; Mus; Mutate; Neuraminidase; Plasma Cells; Population; Proliferating; Proteins; Research; Role; Seasons; Secondary Immunization; Secondary to; Serum; Site; Specificity; Structure; Structure of germinal center of lymph node; T-Lymphocyte; T-Lymphocyte Epitopes; T-cell receptor repertoire; Tamoxifen; Testing; Vaccination; Vaccines; Variant; Viral; Virus; Work; arms race; design; experimental study; imprint; influenza infection; influenza virus strain; influenzavirus; mutant; nonhuman primate; novel vaccines; pathogen; programs; recruit; response; secondary infection; vaccine development

Abstract Naive B cells expressing low affinity antigen-receptors (BCRs) are activated by antigens (Ags), and enter germinal centers (GCs) where hypermutation of BCR gene rearrangements (SHM) drives selection for higher affinity mutants (affinity maturation). Specialized T cells, TFH, also enter GCs and are the agents of high-affinity selection. Inferences regarding the fates of GC B and T cells after influenza immunization or infection have been largely indirect. We will follow the fates of GC T and B cells directly by immunizing or infecting S1pr2CreERT2-RFPLSL mice. In this strain, GC B and T cells (and their progeny) can be labeled by giving mice Tamoxifen. This conditional marking will allow us to follow the fate decisions of GC B cells: whether they become antibody (Ab)-secreting plasmacytes (PCs) or quiescent memory B cells (Bmem). On re-exposure – boost immunizations or secondary infections – we can then follow the roles of primary post- GC B and T cells (RFP+) or newly recruited cells (RFP-) in the secondary responses. This analysis will be important for understanding “imprinting” by influenza HA and NA Ags, the persistence of Bmem cells at local and distal sites, and the persistence of long-lived PC in the bone marrow. The results of this research will also be important for understanding the evolutionary “arms race” between host immunity and mutating virus -- a major issue for vaccine development and for understanding the fundamental biology of humoral responses to variant pathogens.

摘要 表达低亲和力抗原受体（BCR）的幼稚B细胞被抗原（Ag）激活， 并进入生殖中心（GC），其中BCR基因重排（SHM）的超突变 驱动选择更高亲和力的突变体（亲和力成熟）。特化T细胞，TFH， 进入GC，是高亲和力选择的代理人。关于GC B命运的推断 而流感免疫或感染后的T细胞在很大程度上是间接的。我们将遵循 直接免疫或感染S1 pr 2CreERT 2-RFPLSL小鼠，观察GCT和B细胞的命运。在 该品系、GC B和T细胞（及其后代）可以通过给予小鼠他莫昔芬来标记。这 条件标记将使我们能够跟踪GC B细胞的命运决定：它们是否成为 分泌抗体（Ab）的浆细胞（PC）或静止记忆B细胞（BCRs）。再次暴露时 - 加强免疫或继发感染-然后我们可以遵循主要后- 二次应答中的GC B和T细胞（RFP+）或新募集的细胞（RFP-）。这 分析对于理解流感HA和NA Ag的“印记”非常重要， 在局部和远端部位的B细胞的持久性，以及长寿命的PC在局部和远端部位的持久性。 骨髓这项研究的结果也将是重要的了解 宿主免疫与变异病毒的进化“军备竞赛”--疫苗面临的主要问题 发展和了解体液反应的基础生物学变异 病原体