Cytokine control of Red Blood Cell Alloimmunization

红细胞同种免疫的细胞因子控制

• 批准号: 8424288
• 负责人: CHANCE MARION JOHN LUCKEY
• 金额: $ 19.71万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-15 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8424288
• 关键词: Address; Alleles; Alloimmunization; Antibody Formation; Antigens; Automobile Driving; B cell differentiation; B-Cell Development; B-Lymphocytes; Biochemical Genetics; Blood; CD4 Positive T Lymphocytes; Cell Differentiation process; Cells; Cessation of life; Chromatin; Chromatin Remodeling Factor; Clinical; Complex; Cytokine Signaling; Development; Diagnostic; Erythrocyte Transfusion; Erythrocytes; Event; Generations; Genetic Programming; Helper-Inducer T-Lymphocyte; Human; Immunization; Immunoglobulin-Secreting Cells; Infectious Agent; Interleukin-6; Isoantibodies; Lead; Life; Lymphocyte; Maintenance; Measures; Medicine; Modeling; Molecular; Molecular Target; Morbidity - disease rate; Mouse Strains; Mus; PI3K/AKT; Patients; Phosphorylation; Post-Translational Protein Processing; Process; Production; Reaction; Research; Resources; STAT3 gene; Series; Signal Pathway; Signal Transduction; Staging; Sterility; T cell differentiation; T-Cell Activation; T-Lymphocyte; Testing; Therapeutic; Time; Transfusion; Vaccination; Work; cellular targeting; clinically relevant; cytokine; human FRAP1 protein; in vivo; mTOR Signaling Pathway; member; mortality; mouse model; novel; receptor; research study; response; tool; transcription factor

DESCRIPTION (provided by applicant): RBC alloimmunization remains a common clinical problem in transfusion medicine. Alloantibodies are responsible for both immediate and delayed hemolytic transfusion reactions; leading to substantial morbidity and occasional mortality. For those patients unfortunate enough to make multiple alloantibodies, provision of compatible RBCs can be both time and resource intensive. In some cases, this can result in an inability to locate an otherwise life-saving therapy. Despite its clinical importance, the fundamental molecular signals that drive RBC immunization remain unclear. Like infectious agents, the generation of alloantibodies to RBCs requires the activation of antigen specific CD4+ T cells and B cells, where naove CD4+ T cells differentiate into T Follicular Helper cells (TFH) that are essential for complete B cell differentiation into antibody secreting cells. However, our understanding of the molecular mechanisms by which naove CD4+ T cells are induced to differentiate and express a TFH genetic program "in vivo" remains partial. Furthermore, the molecular factors responsible for naove T cell activation and TFH differentiation by the relatively weak stimulant of RBC transfusion are unknown. If we are to ever successfully intervene in this pathogenic process, we must first identify the cellular targets and molecular signals responsible for RBC alloantibody generation. The development of clinically relevant mouse models of RBC storage and transfusion provides a novel set of tools to address this issue. Recent work in these models demonstrated that RBC alloimmunization is enhanced by RBC storage, and that transfusion of stored RBCs significantly increases the systemic production of multiple cytokines including IL-6. We have subsequently demonstrated that i) IL-6 deficient mice are less susceptible to RBC alloimmunization in both fresh and stored blood settings, ii) IL-6 signaling activates the PI3K/AKT/mTOR signaling pathway in naove CD4+ T cells, and iii) induction of PI3K/AKT/mTOR signals correlates with increased phosphorylation of multiple members of the BAF chromatin remodeling complex in primary naove T cells. We therefore propose to identify the specific cellular targets of IL-6 in RBC alloimmunization, and further determine the molecular signals in naove CD4+ T cells induced by IL-6. The objective of our research plan is to test the specific hypothesis that the IL-6 induced by transfusion of fresh and stored RBCs drives TFH differentiation from naove CD4+ T cells. Furthermore, we hypothesize that IL-6 signaling induces phospho-modulation of the BAF chromatin remodeling complex via the action of the PI3K/AKT/mTOR signaling pathway. We will test our hypothesis by combining a well established mouse model of RBC alloimmunization and storage with recently developed mouse strains expressing a floxed allele of IL-6 Receptor (IL-6RA). In the fullness of time, we anticipate that identification of the molecular circuitry driving RBC antibody production will provide therapeutic and diagnostic targets for further clinical development.

描述（由申请人提供）：红细胞同种异体免疫仍然是输血医学中常见的临床问题。同种抗体可引起即刻和延迟的溶血性输血反应，导致大量发病和偶尔死亡。对于那些不幸产生多种同种抗体的患者，提供相容的RBC可能是时间和资源密集型的。在某些情况下，这可能导致无法找到其他挽救生命的治疗方法。尽管具有临床重要性，但驱动红细胞免疫的基本分子信号仍不清楚。与感染因子一样，针对RBC的同种抗体的产生需要抗原特异性CD 4 + T细胞和B细胞的活化，其中新的CD 4 + T细胞分化成T滤泡辅助细胞（TFH），其对于B细胞完全分化成抗体分泌细胞是必需的。然而，我们的理解的分子机制，其中naove CD 4 + T细胞诱导分化和表达TFH遗传程序“体内”仍然是部分的。此外，红细胞输注的相对较弱刺激物导致naove T细胞活化和TFH分化的分子因子尚不清楚。如果我们要成功地干预这一致病过程，我们必须首先确定负责RBC同种抗体产生的细胞靶点和分子信号。红细胞储存和输血的临床相关小鼠模型的开发提供了一套新的工具来解决这个问题。最近在这些模型中的研究表明，RBC同种免疫通过RBC储存而增强，并且储存的RBC的输注显著增加了多种细胞因子（包括IL-6）的全身产生。我们随后证明了i）IL-6缺陷型小鼠在新鲜和储存的血液环境中对RBC同种免疫较不敏感，ii）IL-6信号传导激活naove CD 4 + T细胞中的PI 3 K/AKT/mTOR信号传导途径，和iii）PI 3 K/AKT/mTOR信号的诱导与原代naove T细胞中BAF染色质重塑复合物的多个成员的磷酸化增加相关。因此，我们建议在红细胞同种免疫中鉴定IL-6的特异性细胞靶点，并进一步确定IL-6诱导的naove CD 4 + T细胞中的分子信号。我们的研究计划的目的是检验由新鲜和储存的RBC输注诱导的IL-6驱动来自原始CD 4 + T细胞的TFH分化的特定假设。此外，我们假设IL-6信号通过PI 3 K/AKT/mTOR信号通路的作用诱导BAF染色质重塑复合物的磷酸化调节。我们将测试我们的假设相结合的RBC同种异体免疫和存储与最近开发的小鼠品系表达一个floxed等位基因的IL-6受体（IL-6 RA）建立良好的小鼠模型。随着时间的推移，我们预计驱动RBC抗体产生的分子电路的鉴定将为进一步的临床开发提供治疗和诊断靶点。