Long-lived plasma cell differentiation

长寿命浆细胞分化

• 批准号: 7497525
• 负责人: MICHIKO SHIMODA
• 金额: $ 18.03万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7497525
• 关键词: Address; Adoptive Transfer; Affinity; Alleles; Antibodies; Antibody Affinity; Antigen Presentation; Antigens; Autoimmunity; B cell differentiation; B-Lymphocytes; Blast Cell; Bone Marrow; CD4 Positive T Lymphocytes; Cell physiology; Cell surface; Chickens; Condition; DNA; Differentiation Antigens; Enzyme-Linked Immunosorbent Assay; Fab Immunoglobulins; Ficoll; Frequencies; Gamma globulin; Gene Expression; Generations; Haptens; Helper-Inducer T-Lymphocyte; Homeostasis; Humoral Immunities; IgG1; Immune response; Immunization; In Vitro; Investigation; Label; Lead; Life; Measures; Memory; Memory B-Lymphocyte; Molecular; Mus; Nitrophenol; Numbers; Outcome; PTPRC gene; Pathway interactions; Plasma; Plasma Cells; Population; Reactive Plasma Cell; Receptors, Antigen, B-Cell; Residual state; Rest; Reverse Transcriptase Polymerase Chain Reaction; Role; Simulate; Spleen; System; T-Lymphocyte; TNFSF5 gene; Testing; Time; Transgenes; Transgenic Organisms; Vaccination; Week; base; congenic; cytokine; experience; mouse model; pathogen; plasma cell differentiation; prevent; recombinase; vaccine development

DESCRIPTION (provided by applicant): This proposal employs model mouse systems to address fundamental questions regarding the mechanism of long-term humoral immune response to pathogens. Long-lived plasma cells (PCs) in bone marrow (BM) are responsible for establishing protective life-long humoral immunity. Fully understanding differentiation mechanism of long-lived PC is critical for advanced vaccine development. We generated IA-B mice that lack MHC-II on about 95% of all B cells due to B-cell-restricted deletion of a loxP-flanked iab neo allele by the cd19cre Cre recombinase transgene. Upon immunization with a T cell dependent antigen, a small number of antigen-specific MHC-II+ B cells in IA-B mice dramatically expand to differentiate into GC B cells and make normal level of B220+ CD38+ memory B cells. However, these memory B cells lose MHC-II expression later because of on-going deletion of MHC-II by the cd19cre transgene, thus providing a unique system to study the role of MHC-II-dependent antigen presentation by memory B cells in humoral immunity. In association with loss of MHC-II on memory B cells, IA-B mice showed impaired affinity maturation in long-lived PCs. The hypothesis proposed here is that differentiation of memory B cells into long-lived PCs requires MHC-II dependent antigen presentation. The specific aims to test our hypothesis are: 1) determine the intrinsic requirement MHC-II in memory B cells function, by in vitro culture of purified VH transgenic MHC-II positive and MHC-II negative memory B cells in the presence of various stimulation conditions simulating T cell dependent or T cell independent stimulation and 2) determine the role of MHC-II in PC differentiation pathway of memory B cells, by adoptive transfer of purified VH transgenic MHC-II positive and MHC-II negative memory B cells into antigen-experienced or un-experienced recipient mice. These studies will establish whether MHC- II is required for memory function and whether T cells direct memory B cell differentiation to PC. This will form the basis for further investigations to elucidate the molecular mechanism and 'checkpoints' in the pathway of long-term humoral immunity. The outcome will be valuable for effective vaccine development as well as treating autoimmunity associated with PC differentiation of self-reactive memory B cells. Vaccination generates a small fraction of resting-memory B cells and long-lived plasma cells secreting protective antibody. This study will test whether differentiation of memory B cells to long-lived plasma cells requires MHC-II, a very important molecule for interacting with T cells. This study will further examine how this MHC-II molecule is important for memory B cell function in order to develop better vaccination.

描述（由申请人提供）：本提案采用模型小鼠系统来解决关于病原体长期体液免疫反应机制的基本问题。骨髓中的长寿命浆细胞（pc）负责建立保护性终身体液免疫。充分了解长寿命PC的分化机制对疫苗的后期开发至关重要。由于cd19cre - Cre重组酶转基因导致B细胞限制性缺失loxp侧的iab - neo等位基因，我们产生了大约95%的B细胞缺乏MHC-II的IA-B小鼠。免疫T细胞依赖抗原后，IA-B小鼠体内少量抗原特异性MHC-II+ B细胞显著扩增分化为GC B细胞，并形成正常水平的B220+ CD38+记忆B细胞。然而，由于cd19cre转基因导致MHC-II持续缺失，这些记忆B细胞随后失去MHC-II表达，从而为研究记忆B细胞MHC-II依赖性抗原呈递在体液免疫中的作用提供了一个独特的系统。与记忆B细胞上MHC-II的缺失相关，IA-B小鼠在长寿命pc中表现出亲和力成熟受损。这里提出的假设是，记忆B细胞分化为长寿的pc细胞需要MHC-II依赖抗原呈递。检验我们假设的具体目的是：1)通过体外培养纯化的VH转基因MHC-II阳性和MHC-II阴性记忆B细胞，在模拟T细胞依赖或T细胞独立刺激的各种刺激条件下，确定MHC-II在记忆B细胞PC分化途径中的作用，确定记忆B细胞功能的内在需求。通过将纯化的VH转基因MHC-II阳性和MHC-II阴性记忆B细胞过继转移到抗原经历或未经历的受体小鼠中。这些研究将确定记忆功能是否需要MHC- II，以及T细胞是否直接将记忆B细胞分化为PC。这将为进一步研究阐明长期体液免疫途径中的分子机制和“检查点”奠定基础。该结果将对有效的疫苗开发以及治疗与自我反应记忆B细胞PC分化相关的自身免疫具有价值。疫苗接种产生一小部分静止记忆B细胞和长寿命浆细胞分泌保护性抗体。这项研究将测试记忆B细胞向长寿浆细胞的分化是否需要MHC-II， MHC-II是一种与T细胞相互作用的非常重要的分子。这项研究将进一步研究MHC-II分子对记忆B细胞功能的重要性，以开发更好的疫苗接种。