LIAI Epitope Validation Center: Characterization of Allergen specific T Cells

描述(由申请人提供：该计划的总体范围是利用特征良好的T细胞变应原表位的可用性来测试特定的假设，这些假设是通过分析先前授予LIAI和Benaroya Institutes的大规模变应原表位鉴定合同产生的数据而产生的。我们先前注意到，作为对Timothy Grass(TG)提取物的反应，正如预期的那样，TH2细胞因子占主导地位。然而，干扰素γ的产生与变应性鼻炎有关，IL17与过敏性哮喘有关。项目1(Sette Pi)将测试这一假设，即不同的阶段(季节与反季节)、类型(鼻炎与哮喘)和过敏性疾病的严重程度与T细胞反应的不同幅度以及不同TH亚群的不同相互作用有关。在这里，纵向研究将确定体外和体外扩增后特定表位的TH亚群的相对大小，我们将表征它们的出现和相互作用的动力学，作为季节性和疾病严重程度的函数。项目2(彼得斯PI)将检验SIT治疗和临床疗效与调节T细胞反应有关的假设。具体地说，我们将测试SIT治疗影响T细胞对一组新抗原的反应的假设，这些抗原是我们实验室正在鉴定的，但不被IgE反应识别。对已知和新抗原的反应将与多个表型T细胞标记物一起纵向测量。具体的假设将检验TFH亚群在调节抗体反应中的作用，以及IL10产生细胞在抑制TH2反应中的作用。项目3(Rao Pi)将通过比较从哮喘和过敏性鼻炎患者血液中分离出的表位特异性T细胞中的组蛋白修饰和DNA甲基化/羟甲基化模式，确定与哮喘发展和严重程度以及SIT治疗相关的表观遗传学特征。大量的初步数据表明，转录因子和表观遗传机制之间的相互作用不仅启动了免疫细胞的分化，而且维持了长期的分化状态。因此，我们将检验这一假设，即哮喘的特征是相关疾病相关基因组座位上的长期表观遗传变化。拟议研究的结果将是产生有效的过敏原表位数据，并将其传播给科学界。这将实现RFA“变应原表位研究和验证中心”的意图，为变态反应性疾病中T细胞反应的靶点和性质提供新的见解，并为诊断和治疗干预提供潜在的途径。

DESCRIPTION (provided by applicant: The overall scope of this program is to capitalize on the availability of well-characterized T cell allergen epitopes to test specific hypotheses that arose from analysis of the data generated by the previous Large Scale Allergen Epitope Identification contracts, awarded to LIAI and Benaroya Institutes. We previously noted that in response to Timothy Grass (TG) extract, as expected TH2 cytokines predominate. However, IFNγ production was associated with allergic rhinitis and IL17 with allergic asthma. Project 1 (Sette PI) will test the hypothesis that different stages (in-season versus out-of-season), types (rhinitis versus asthma) and severities of allergic disease are associated with differential magnitude of T cell responses, and also distinctive interplay of different TH subsets. Here, longitudinal studies will determine the relative size of TH subsets specific for defined epitopes both ex vivo and after in vitro expansion and we will characterize their kinetics of appearance and interplay as a function of seasonality and disease severity. Project 2 (Peters PI) will test th hypothesis that SIT treatment and clinical efficacy is associated with modulating the T cell response. Specifically, we will test the hypothesis that SIT treatment affects T cell responses to a set of novel antigens that are being identified by our laboratory that are not recognized by IgE responses. Responses to both known and novel antigens will be measured longitudinally along with multiple phenotypic T cell markers. Specific hypotheses will examine the role of Tfh subsets in modulating antibody responses and the role of IL10 producing cells in suppressing TH2 responses. Project 3 (Rao PI) will identify epigenetic signatures that correlate with asthma development and severity, as well as SIT treatment, by comparing histone modifications and DNA methylation/ hydroxymethylation patterns in epitope specific T cells isolated from blood of asthmatic versus allergic rhinitis patients. Extensive preliminary data indicates that the interpla between transcription factors and epigenetic mechanisms not only initiates immune cell differentiation but also maintains the long-term differentiated state. Accordingly, we will test th hypothesis that asthma is characterized by long-range epigenetic changes at relevant disease-associated genomic loci. The outcome of the proposed research will be the generation of validated allergen epitope data, and its dissemination to the scientific community. This will fulfil the intent of the RFA "Allergen Epitope Research and Validation Centers", provide new insight into the targets and the nature of T cell responses in allergic disease, and provide potential avenues for diagnostic and therapeutic intervention.