Human B1-like Cells and Pneumococcal Defense in the Elderly

人类 B1 样细胞和老年人的肺炎球菌防御

基本信息

批准号：
10330573
负责人：
THOMAS L ROTHSTEIN
金额：
$ 37.75万
依托单位：
WESTERN MICHIGAN UNIV SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-02-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10330573
关键词：
Address Adoptive Transfer Age Aging Antibodies Antibody Repertoire Antigens Attention B-Lymphocytes Bacteria Binding Biological Assay Cell Count Cell Separation Cell physiology Cell secretion Cells Characteristics Cloning Communicable Diseases Diagnosis Elderly Enzyme-Linked Immunosorbent Assay Failure Flow Cytometry Functional disorder Future Human Immune Immune System Diseases Immunity Immunization Immunoglobulin M Immunoglobulins Individual Infection MS4A1 gene Modeling Morbidity - disease rate Mus Nature Organism Performance Persons Phosphorylcholine Pneumococcal Infections Pneumococcal vaccine Population Process Reporting Rest Role Serology Serum Severity of illness Specificity Stains Streptococcus pneumoniae System Time Vaccination Vaccines Work age related enzyme linked immunospot assay experimental study immune function improved in vivo microbial mortality natural antibodies novel therapeutic intervention

项目摘要

The broad, long term objective of this project is to elucidate the mechanism or mechanisms underlying the relative deficiency of serological immunity in the elderly, with particular attention to human B1-like cells and natural antibodies derived therefrom. The specific focus of the present application is to understand the age- related failure of immune defense against infection with S. pneumoniae, both at rest and after immunization with pneumococcal vaccine. A key mechanism for disposing of infectious pneumococci lies in opsonization by serum antibody, and a principal target for opsonizing antibody is phosphorylcholine (PC). Thus, we will study B cells, particularly B1-like cells, that bind PC and secrete anti-PC antibodies. It is known that human serum contains antibodies against PC, that human B1-like cells recognize PC, and that the total population of human B1-like cells declines with age. But it is not known what happens to PC-binding B1-like cells in older individuals as compared to younger individuals. In mice, where adoptive transfer experiments are possible, serum IgM derived from B1 cells of older mice fails to alter the course of pneumococcal infection in mice lacking antibody, whereas an equal amount of serum IgM from younger mice is effective. This coincides with an age-related change in the underlying nature of mouse B1 cell anti- PC antibodies as transcribed immunoglobulin becomes less germline in sequence. These reports regarding age-related changes in total human B1-like cell number and in mouse B1 cell anti-PC antibody repertoire suggest mechanisms for the failure of pneumococcal defense in older people. We hypothesize that the relative deficiency of serological immunity against PC/pneumococci in older humans, before and after pneumococcal vaccination, is due to one or more of: age-related loss of PC- binding B1-like cells, erosion of B1-like cell anti-PC antibody sequence/repertoire, and dysfunction of PC- binding B1-like cells/poor function of B1-like cell anti-PC antibodies. These characteristics have either never been studied in human B1-like cells or never been examined in antigen-specific human B1-like cells with respect to age. We will determine the validity of our hypotheses through the following aims in which we will compare older vs younger healthy donors, and older donors before and after pneumococcal vaccination. SA1. We will evaluate the level of PC-binding B1-like cells, by immunofluorescent staining for B cell subpopulations and PC-binding, followed by flow cytometry/cell sorting. SA2. We will determine the sequence/repertoire of PC-binding B1-like cell antibodies by single cell PCR followed by sequencing, cloning, and ELISA for specificity. SA3. We will evaluate the function of PC-binding B1-like cells and the antibodies they produce, by determining B1-like cell secretion with ELISPOT assays and determining anti- pneumococcal function with opsonophagocytic assays. This work will provide completely new information that will suggest new ways to improve anti-pneumococcal antibody immune defense in the elderly.

该项目的广泛、长期目标是阐明潜在的机制老年人血清学免疫相对缺乏，尤其关注人类B1样细胞和本申请的具体重点是了解由其衍生的天然抗体。在休息时和免疫后，针对肺炎链球菌感染的免疫防御失败肺炎球菌疫苗处理传染性肺炎球菌的关键机制在于调理作用。血清抗体，调理抗体的主要目标是磷酸胆碱（PC）。研究结合 PC 并分泌抗 PC 抗体的 B 细胞，特别是 B1 样细胞。众所周知，人血清中含有抗 PC 的抗体，人类 B1 样细胞可识别该抗体 PC，并且人类 B1 样细胞的总数随着年龄的增长而下降，但尚不清楚会发生什么。与年轻个体相比，老年个体的 PC 结合 B1 样细胞。转移实验是可能的，来自老年小鼠 B1 细胞的血清 IgM 未能改变病程肺炎球菌感染小鼠缺乏抗体，而年轻小鼠血清中等量的 IgM 这与小鼠 B1 细胞抗衰老的潜在性质的变化相一致。 PC 抗体作为转录的免疫球蛋白依次变得较少种系。人类 B1 样细胞总数和小鼠 B1 细胞抗 PC 抗体库的年龄相关变化提出了老年人肺炎球菌防御失败的机制。我们假设老年人对 PC/肺炎球菌的血清学免疫相对缺乏。人类在接种肺炎球菌疫苗之前和之后，是由于以下一种或多种原因造成的：与年龄相关的PC- 结合 B1 样细胞、B1 样细胞抗 PC 抗体序列/库的侵蚀以及 PC 功能障碍结合 B1 样细胞/B1 样细胞抗 PC 抗体功能较差。已在人类 B1 样细胞中进行过研究，或从未在抗原特异性人类 B1 样细胞中进行过检查我们将通过以下目标来确定我们假设的有效性。比较老年与年轻健康捐赠者以及老年捐赠者在肺炎球菌疫苗接种前后的情况。我们将通过 B 细胞的免疫荧光染色来评估 PC 结合 B1 样细胞的水平。亚群和 PC 结合，然后进行流式细胞术/细胞分选。通过单细胞 PCR 和测序得到 PC 结合 B1 样细胞抗体的序列/库，克隆和 ELISA 的特异性。SA3。我们将评估 PC 结合 B1 样细胞的功能和他们产生的抗体，通过使用 ELISPOT 测定法测定 B1 样细胞分泌并测定抗这项工作将提供全新的信息。这将为改善老年人抗肺炎球菌抗体免疫防御提供新方法。