Cytokine signaling in developing thymocytes and T cells

发育中的胸腺细胞和 T 细胞中的细胞因子信号传导

• 批准号: 10014532
• 负责人: Alfred Singer
• 金额: $ 28.48万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10014532
• 关键词: CD8B1 gene; Cell Lineage; Cells; Cues; Cytokine Signaling; Cytotoxic T-Lymphocytes; Data; Disputes; Goals; Interleukin 7 Receptor; Interleukin-6; Interleukin-7; Kinetics; Malignant Neoplasms; Mature T-Lymphocyte; Modality; Modeling; Natural Killer Cells; Outcome; Receptor Signaling; Role; Signal Transduction; Signaling Molecule; Specificity; T-Cell Development; T-Cell Receptor; T-Lymphocyte; TSLP gene; Therapeutic; Thymus Gland; cytokine; in vivo; thymocyte

The conventional view on T cell development posits that signals from the same T cell receptor (TCR) determines both positive and negative selection as well as lineage choice into mature CD4+ helper and CD8+ cytotoxic cells. The precise mechanism how this is achieved is still under dispute but it has been proposed that either quantitative or qualitative differences in TCR signaling would account for the different outcomes of lineage choice. In contrast to such views, here we show that TCR signaling alone is not sufficient to determine cell fate of developing thymocytes, and that CD4/CD8 lineage choice requires additional cues by cytokines such as interleukin-7 (IL-7). Using conditional deletion of immediate downstream signaling molecules of the IL-7 receptor, we demonstrate that IL-7 induced cytokine signals are required for CD8 lineage choice and for the differentiation into mature CD8+ cytotoxic T cells in vivo. Our data establish a previously unappreciated role for in vivo IL-7 and other gamma c-cytokines in CD8 lineage commitment of immature thymocytes, which is consistent with the kinetic signaling model of T cell lineage choice. We have recently also identified an unexpected role for non-gamma c-cytokines (IL-6, TSLP, and IFNgamma) in CD8 lineage commitment and are actively analyzing their mode of action during positive selection in the thymus.

T 细胞发育的传统观点认为，来自同一 T 细胞受体 (TCR) 的信号决定了正选择和负选择以及成熟 CD4+ 辅助细胞和 CD8+ 细胞毒性细胞的谱系选择。实现这一目标的精确机制仍存在争议，但有人提出，TCR 信号传导的定量或定性差异将解释谱系选择的不同结果。与这些观点相反，我们在这里表明，仅 TCR 信号传导不足以确定发育中胸腺细胞的细胞命运，并且 CD4/CD8 谱系选择需要细胞因子（例如白细胞介素 7 (IL-7)）的额外提示。通过条件性删除 IL-7 受体的直接下游信号分子，我们证明 IL-7 诱导的细胞因子信号是 CD8 谱系选择和体内分化为成熟 CD8+ 细胞毒性 T 细胞所必需的。我们的数据证实了体内IL-7和其他γc细胞因子在未成熟胸腺细胞CD8谱系定型中的先前未被认识到的作用，这与T细胞谱系选择的动力学信号模型一致。我们最近还发现了非 γ c 细胞因子（IL-6、TSLP 和 IFNgamma）在 CD8 谱系定型中的意外作用，并正在积极分析它们在胸腺正选择过程中的作用模式。