Extrathymic T cell precursors: commitment and efficacy

胸腺外 T 细胞前体：承诺和功效

• 批准号: 7882652
• 负责人: HARALD VON BOEHMER
• 金额: $ 39.02万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7882652
• 关键词: Address; Aftercare; Blood; Blood Cells; Bone Marrow; Bone Marrow Transplantation; Cell Lineage; Cells; Clinical; Commit; Cytotoxic agent; Dependence; Dependency; Development; Gene Expression; Gene Expression Regulation; Generations; Genes; Genetic Transcription; Goals; Home environment; Homing; Hour; Immigrant; Immune system; In Vitro; Infection; Injection of therapeutic agent; Lymphoid; Lymphoid Cell; Lymphopoiesis; Malignant Neoplasms; Molecular Analysis; Mus; Myelogenous; Natural regeneration; Nature; Normal Cell; PTPRC gene; Pathway interactions; Phenotype; Procedures; Proto-Oncogene Protein c-kit; Reporter Genes; Staging; Stem cells; Surface; T-Cell Depletion; T-Lymphocyte; Thymus Gland; comparative; in vivo; irradiation; notch protein; progenitor; prototype; public health relevance; reconstitution; research study; self-renewal

DESCRIPTION (provided by applicant): The nature of thymus immigrants that contribute most effectively to T lymphopoiesis is unknown even though several well-characterized progenitors have been described. Some of these cells can give rise to lymphoid and non-lymphoid lineages, others are lymphoid-restricted and yet others are T lymphoid lineage-restricted. Cells with T lineage-restricted potential, circulating T cell progenitors (CTP), have recently been described in the blood with the aid of a pre-TCR1- controlled reporter gene. Here it is proposed to further phenotypically characterize CTP and their progeny and to analyze their efficacy in T cell generation and commitment to the T cell lineage in further detail. Furthermore, the Notch dependence of T lineage commitment will be addressed in mice with reversible inhibition of Notch-dependent transcription by analyzing the generation of cells with a CTP surface phenotype from precursors that are deficient in Notch- dependent transcription. Subsequently, after isolation of CTP and relieving the transcriptional block, the functional potential will be determined. Finally, gene expression of CTP will be compared with that of multipotent (LSK) and intrathymic (ETP) precursors in an attempt to place these cells in a differentiation pathway. Special emphasis will be given to gene regulation by the LRF gene that antagonizes Notch in early precursors of lymphoid cells. In a second aim, the efficacy of several well-characterized extrathymic precursors to generate T cells will be compared by depleting such precursors prior to injecting bone marrow or blood cells into Il-7ra- deficient recipients. In additional studies lineage fate tracing by IL-7R1-cre will be used to determine the contribution of IL-7R1-expressing precursors to intrathymic precursors such as ETP. Furthermore, the short-term potential of cells to home to the thymus will be compared 24 hours after injection of cells by explanting intrathymic donor-derived cells under conditions of limiting dilution into cultures containing OP9-DL1 feeder cells. Once information on different precursors with either multipotential (prototype LSK), lymphoid-restricted potential (prototype CLP) or T lineage-restricted potential (prototype CTP) has been established these subsets will be further subdivided by already established markers in order to pinpoint the most relevant precursors as precisely as possible. Overall this project aims at establishing mechanisms of extrathymic T lineage commitment as well as identifying the most potent extrathymic precursors for T lymphopoiesis. PUBLIC HEALTH RELEVANCE: This project aims at the identification and characterization of the most effective cells in bone marrow and blood that under different conditions permit the reconstitution of the T cell immune system that protects from infection and malignancy. Identification of the extrathymic T cell precursors will help in the faster regeneration of the immune system after treatment of malignancy by x- irradiation and/or cytotoxic drugs that result in T cell depletion.

描述（由申请人提供）：即使已经描述了几个特征良好的祖细胞，对淋巴管造成最有效贡献的胸腺移民的性质是未知的。这些细胞中的一些会引起淋巴样和非淋巴谱系，另一些细胞受到淋巴的限制，而另一些细胞则受到T淋巴谱系的限制。最近在血液中描述了具有T谱系限制性电位，循环T细胞祖细胞（CTP）的细胞，该细胞借助于TCR1控制的报告基因。在这里，建议进一步表征CTP及其后代，并进一步详细地分析其在T细胞产生中的功效和对T细胞谱系的承诺。此外，通过分析从缺乏缺陷notch依赖性转录的前体中的CTP表面表型的细胞产生，将在小鼠中解决T谱系承诺的缺口依赖性。随后，在分离CTP并缓解转录块后，将确定功能电位。最后，将CTP的基因表达与多能（LSK）和胸膜内（ETP）前体的基因表达进行比较，以尝试将这些细胞放置在分化途径中。 LRF基因将特别强调基因调节，该基因在淋巴样细胞的早期前体中拮抗Notch。在第二个目标中，将通过在将骨髓或血细胞注入IL-7RA缺乏的受体之前耗尽此类前体来比较几个特征良好的外激发前体的疗效。在其他研究中，IL-7R1-CRE的谱系命运追踪将用于确定表达IL-7R1的前体对静脉内肌前体（例如ETP）的贡献。此外，在细胞注射后24小时将细胞对胸腺的短期潜力通过在限制稀释到含有OP9-DL1喂食器细胞的培养物的条件下，通过化热供体衍生的细胞来比较细胞。一旦有关多能元（原型LSK）的不同前体的信息，淋巴样限制电位（原型CLP）或T谱系限制电位（原型CTP）的信息将被已经建立的标记进一步细分，以便以预见的准确性来查明最相关的前体。总体而言，该项目旨在建立外激体T谱系承诺的机制，并确定T淋巴管菌的最有效的外肌外体前体。公共卫生相关性：该项目旨在识别和表征骨髓和血液中最有效的细胞，这些细胞在不同条件下允许重建T细胞免疫系统，以保护免受感染和恶性肿瘤的影响。鉴定外肌T细胞前体的鉴定将有助于通过X-辐照和/或细胞毒性药物治疗恶性肿瘤后的免疫系统更快再生，从而导致T细胞消耗。