LIAI Epitope Validation Center: Characterization of Allergen specific T Cells

描述（由申请人提供）：该项目的总体范围是利用具有良好特征的T细胞过敏原表位的可用性来测试先前授予LIAI和Benaroya研究所的大规模过敏原表位鉴定合同所产生的数据分析所产生的特定假设。我们之前注意到，在对Timothy Grass （TG）提取物的反应中，正如预期的那样，TH2细胞因子占主导地位。然而，IFNγ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）将检验不同阶段（季节性与非季节性）、类型（鼻炎与哮喘）和过敏性疾病严重程度与不同程度的T细胞反应相关的假设，以及不同TH亚群的独特相互作用。在这里，纵向研究将确定体外和体外扩增后特定于定义表位的TH亚群的相对大小，我们将表征其外观动力学和相互作用作为季节性和疾病严重程度的函数。项目2 （Peters PI）将验证SIT治疗和临床疗效与调节T细胞反应有关的假设。具体来说，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鉴定的，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的表位特异性T细胞的组蛋白修饰和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特征。大量的初步数据表明，转录因子与表观遗传机制之间的相互作用不仅启动免疫细胞分化，而且维持免疫细胞的长期分化状态。因此，我们将验证哮喘以相关疾病相关基因组位点的长期表观遗传变化为特征的假设。拟议研究的结果将是产生经过验证的过敏原表位数据，并将其传播到科学界。这将实现RFA“过敏原表位研究和验证中心”的意图，为过敏性疾病中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.