TCR Diagnostics in LGL Leukemia and Immune Cytopenias

LGL 白血病和免疫性血细胞减少症的 TCR 诊断

• 批准号: 7554635
• 负责人: Jaroslaw P Maciejewski
• 金额: $ 28.65万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-15 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7554635
• 关键词: Allogenic; Anemia; Antigen-Presenting Cells; Antigenic Specificity; Antigens; Autologous; Biological Assay; CD34 gene; CD8B1 gene; Cell Line; Cells; Chronic; Clinical; Clonal Expansion; Clonality; Cytotoxic T-Lymphocytes; Defect; Detection; Development; Diagnosis; Diagnostic; Disease; Disease remission; Effector Cell; Erythrocytes; Erythroid; Erythroid Cells; Evolution; Experimental Models; Family; Feedback; Functional disorder; Generations; Goals; Hematopoiesis Inhibition; Hematopoietic; Immune; Immune response; Immunodominant Antigens; Immunologic Surveillance; Individual; Large granular lymphocyte; Lead; Lymphoma; Lymphoproliferative Disorders; Measures; Mediating; Methodology; Methods; Modeling; Molecular Analysis; Molecular Diagnosis; Molecular Profiling; Molecular Structure; Myelogenous; Neoplasms; Neutropenia; Pancytopenia; Pathology; Pathway interactions; Patients; Peptides; Physiological; Play; Process; Proliferating; Reaction; Regulation; Relative (related person); Role; Sequence Analysis; Specificity; Staging; Staining method; Stains; Stem cells; Syndrome; T memory cell; T-Cell Large Granular Lymphocyte; T-Cell Proliferation; T-Cell Receptor; T-Lymphocyte; Testing; Therapeutic; Undifferentiated; base; cellular targeting; chronic T-cell leukemia; cytopenia; cytotoxic; design; enzyme linked immunospot assay; graft vs host disease; leukemia; novel diagnostics; progenitor; receptor; response; tool

DESCRIPTION (provided by applicant): Large granular lymphocyte (LGL) leukemia is a chronic T cell lymphoproliferation associated with immune-mediated cytopenias and expansion of clonal cytotoxic T cells (CTL). LGL CTL defies natural regulation, and their proliferation appears to be maintained by extrinsic triggers. Additionally, the clonal CTL appear to be the effectors that mediate an immune attack presumably directed against hematopoietic progenitors. As an experimental model LGL leukemia offers an advantage of availability of clonal effector cells and the target cells they recognize. The pathophysiology of LGL leukemia may correspond to a polarized clonal response that constitutes a suitable model for characterizing the role of individual pathogenic T cell clones but also as a basis for comparison with the polyclonal T cell responses accompanying other causes of immune-mediated bone marrow failure states. Under normal circumstances, in the process of immune reaction to specific antigens, immunodominant T cell clones expand. The unique antigen-specific portion of the T cell receptor (TCR), the complementary determining region-3 (CDR3) of the variable portion of the a-chain (VB), can serve as a molecular signature (clonotype) for the antigen-specific T cell clones. Hypothesis: The specificity of the antigenic recognition in LGL may determine its hematologic presentation and cryptic CTL-mediated expansions, analogous to LGL leukemia, may be responsible also in other forms of immune cytopenias. CDR3 clonotypes may constitute suitable targets to study clonal processes and development of new diagnostic tools. Specific Aims: 1) Characterization of LGL T cell clonotypes will allow us to determine if similar clonotypes are shared between the patients (or possibly also found in healthy individuals), as well as to design a new class of diagnostic tools based on the quantitation of pathogenic clones using clonotypic PCR. 2) The specificity of antigenic recognition in LGL leukemia may determine the types of clinical presentation (e.g. anemia, neutropenia). Inhibitory and cytotoxic activity of clonal LGL will be tested against autologous and allogeneic erythroid and myeloid precursors, as well as cell lines and undifferentiated CD34+ cells. 3) Isolation of LGL clones will allow for the generation of soluble TCR molecules that will be applied to identify cellular target cells for LGL CTL. 4) Identification of LGL specific clonotypes will be applied to measure the anti-idiotypic responses directed against LGL and control clones in patients to determine the role of anti-idiotypic feedback in the regulation of autonomous and physiologic clonal expansions. The long-term goals of our proposal include establishment of novel diagnostic strategy based on molecular analysis of TCR. Our studies concentrate on LGL leukemia but in general, molecular analysis of the T cell repertoire can be applied to the study of many hematologic conditions, including immune surveillance of leukemia evolution, immune-mediated bone marrow failure and graft versus host disease.

描述（由申请人提供）：大颗粒淋巴细胞（LGL）白血病是一种与免疫介导的血细胞减少和克隆细胞毒性T细胞（CTL）扩增相关的慢性T细胞淋巴增殖。 LGL CTL 违背自然调节，它们的增殖似乎是由外在触发因素维持的。此外，克隆 CTL 似乎是介导可能针对造血祖细胞的免疫攻击的效应器。作为一种实验模型，LGL 白血病具有克隆效应细胞及其识别的靶细胞的可用性的优势。 LGL 白血病的病理生理学可能对应于极化克隆反应，该反应构成了表征单个致病性 T 细胞克隆的作用的合适模型，而且也作为与伴随免疫介导的骨髓衰竭状态的其他原因的多克隆 T 细胞反应进行比较的基础。正常情况下，在对特定抗原的免疫反应过程中，免疫优势T细胞克隆会扩张。 T 细胞受体 (TCR) 的独特抗原特异性部分，即 a 链 (VB) 可变部分的互补决定区 3 (CDR3)，可以作为抗原特异性 T 细胞克隆的分子特征（克隆型）。假设：LGL 中抗原识别的特异性可能决定其血液学表现，而隐性 CTL 介导的扩增（类似于 LGL 白血病）也可能是其他形式的免疫血细胞减少症的原因。 CDR3 克隆型可能构成研究克隆过程和开发新诊断工具的合适靶标。具体目标：1) LGL T 细胞克隆型的表征将使我们能够确定患者之间是否共享相似的克隆型（或者可能在健康个体中也发现），以及基于使用克隆型 PCR 定量致病性克隆来设计一类新的诊断工具。 2) LGL 白血病抗原识别的特异性可能决定临床表现的类型（例如贫血、中性粒细胞减少症）。克隆 LGL 的抑制和细胞毒性活性将针对自体和同种异体红细胞和骨髓前体细胞以及细胞系和未分化的 CD34+ 细胞进行测试。 3) LGL克隆的分离将允许产生可溶性TCR分子，该分子将用于识别LGL CTL的细胞靶细胞。 4) LGL特异性克隆型的鉴定将用于测量针对患者中LGL和对照克隆的抗独特型反应，以确定抗独特型反馈在调节自主和生理克隆扩张中的作用。我们提案的长期目标包括建立基于 TCR 分子分析的新型诊断策略。我们的研究集中于 LGL 白血病，但总的来说，T 细胞库的分子分析可应用于许多血液学疾病的研究，包括白血病演变的免疫监视、免疫介导的骨髓衰竭和移植物抗宿主病。