LIFETIME OF EFFECTOR B CELLS

效应 B 细胞的寿命

• 批准号: 8362764
• 负责人: Thomas Dorner
• 金额: $ 2.34万
• 依托单位: UNIVERSITY OF CALIF-LAWRNC LVRMR NAT LAB
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362764
• 关键词: Age; Antibodies; Antigens; B-Lymphocytes; Blood; Cells; DNA; Development; Elements; Ensure; Europe; Funding; Grant; Half-Life; Human; Human body; Immune; Immune system; Immunoglobulin-Secreting Cells; Infection; Isotopes; Longevity; Measures; Memory; Memory B-Lymphocyte; Methodology; Methods; National Center for Research Resources; Play; Population; Principal Investigator; Protein Binding; Protocols documentation; Research; Research Infrastructure; Resource Development; Resources; Role; Sample Size; Sampling; Serum; Source; Staging; Tissues; United States National Institutes of Health; Vaccination; Vaccines; accelerator mass spectrometry; base; cell type; cost; fighting; in vivo; insight; pathogen; prevent

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Human body integrity is largely based on a healthy immune system fighting pathogens. One key feature of the immune system is expression of memory, i.e. maintaining the ability to fight a pathogen upon its re-encounter effectively, even after years of pathogen absence. Based on that, vaccinations can prevent from severe infections. In pathogen defense, proteins binding specifically to the pathogen (antibodies) play a vital role. Antibodies tag the pathogen and thus cause highly efficient degradation of the pathogen by specialized immune cells or neutralize it. The physical half-life of antibodies is less than 4 weeks. By contrast, specific antibodies induced by vaccination or infection can be readily detected in human blood serum after decades of antigen absence (humoral memory). This suggests that serum antibody levels are regulated at the stage of antibody secreting cells, and their specific precursors (memory B cells). For both cell types, longevity vs. continuous renewal is discussed as means to maintain the entire cell population and its composition, but both concepts were neither proven nor disproven physically. In this project we want to measure 14C content in the DNA of antibody-secreting cells and memory B cells obtained from donors exposed to elevated levels of atmospheric 14C in Europe during the 1960s. Elevated levels of the 14C isotope can still be detected in cells being quiescent since then, revealing their age. 14C analysis will require accelerator mass spectrometry (AMS) ensuring a precise quantitation of very low levels of 14C from minimum DNA samples. In analogy to Spalding et al (Cell, Vol. 122, 133143, July 15, 2005), this analysis will determine the in vivo age of candidate subsets of antibody-secreting cells and memory B cells and prove or disprove longevity of these cells, arguing in favor or against B cell longevity as a key element of humoral memory. The expected results will define new requirements for the successful development of effective vaccines. AMS will be used in this project to determine the content of 14C in DNA samples isolated from immune cells, thereby revealing their average age. AMS is indispensable as the cell populations to analyze are very rare, thus yielding very small DNA sample size. According to previous studies, the concentration of the 14C within the sample is again very low. Comparable analysis has already been performed at the LLNL and we believe that close cooperation with the resource is necessary to conduct a successful project. Except for the very small sample size, no additional development of methodology appears to be required. The results from 14C analyses will be combined with different results derived from various immunological methods to provide new insight in functionally different effector B cells and mechanisms of humoral memory. AMS results are a vital part of the whole study. Human blood and tissue will be obtained and specific cells will be extracted. From these cells, DNA will be isolated using established protocols compatible with latter 14C quantitation. DNA will be sent to the resource for 14C analysis.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 人体的完整性在很大程度上基于健康的免疫系统抗击病原体。免疫系统的一个关键特征是记忆的表达，即，即使在病原体缺乏后，也可以在病原体上有效地与病原体作斗争的能力。基于此，疫苗接种可以防止严重感染。在病原体防御中，蛋白质特异性与病原体（抗体）的结合起着至关重要的作用。抗体标记病原体，从而通过专门的免疫细胞或中和引起病原体的高效降解。抗体的物理半衰期不到4周。相比之下，几十年来抗原缺失（体液记忆）后，可以在人血清中很容易检测到疫苗接种或感染引起的特异性抗体。这表明血清抗体水平受到抗体分泌细胞及其特定前体（记忆B细胞）的调节。对于两种细胞类型，将寿命与连续更新讨论为维持整个细胞种群及其组成的手段，但是这两个概念均未得到证明也没有被忽视。 在这个项目中，我们希望在1960年代在欧洲暴露于大气中14C升高的供体获得的抗体分泌细胞和记忆B细胞的DNA中测量14C含量。从那时起，仍可以在细胞静止的细胞中检测到14C同位素的水平升高，从而揭示其年龄。 14C分析将需要加速器质谱法（AMS），以确保从最小DNA样品中精确定量14c。与Spalding等人类似（Cell，第122、133 143卷，2005年7月15日），该分析将确定抗体分泌细胞和记忆B细胞的候选子集​​的体内生体，并证明或证明或反对这些细胞的寿命，以支持B细胞的寿命或反对B细胞的寿命，以抗B细胞的寿命为孔隙记忆的关键元素。预期的结果将定义成功开发有效疫苗的新要求。 该项目将使用AM来确定从免疫细胞分离的DNA样品中14C的含量，从而揭示其平均年龄。 AM是必不可少的，因为要分析的细胞群体非常罕见，因此产生了非常小的DNA样本量。根据先前的研究，样品中14C的浓度再次非常低。 LLNL已经进行了可比的分析，我们认为与资源的密切合作是进行成功的项目所必需的。除了非常小的样本量外，似乎不需要其他方法论。 14C分析的结果将与来自各种免疫学方法得出的不同结果相结合，以提供功能上不同的效应B细胞和体液记忆机制的新见解。 AMS结果是整个研究的重要组成部分。 将获得人类血液和组织，并提取特定细胞。从这些细胞中，将使用与后者14C定量兼容的已建立方案分离DNA。 DNA将被发送到资源进行14C分析。