1] Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, USA. [2] Rosalind Russell-Ephraim P. Engleman Rheumatology Research Center, University of California, San Francisco, San Francisco, California, USA. [3] Department of Medicine, University of California, San Francisco, San Francisco, California, USA. [4] Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA. [5].
1] Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, USA. [2] [3].
Nat Immunol. 2014 Jul;15(7):687-94. doi: 10.1038/ni.2918. Epub 2014 Jun 8.
The catalytic activity of Zap70 is crucial for T cell antigen receptor (TCR) signaling, but the quantitative and temporal requirements for its function in thymocyte development are not known. Using a chemical-genetic system to selectively and reversibly inhibit Zap70 catalytic activity in a model of synchronized thymic selection, we showed that CD4(+)CD8(+) thymocytes integrate multiple, transient, Zap70-dependent signals over more than 36 h to reach a cumulative threshold for positive selection, whereas 1 h of signaling was sufficient for negative selection. Titration of Zap70 activity resulted in graded reductions in positive and negative selection but did not decrease the cumulative TCR signals integrated by positively selected OT-I cells, which revealed heterogeneity, even among CD4(+)CD8(+) thymocytes expressing identical TCRs undergoing positive selection.
Zap70 的催化活性对 T 细胞抗原受体 (TCR) 信号转导至关重要，但它在胸腺细胞发育中的功能的定量和时间要求尚不清楚。我们使用一种化学遗传学系统，在同步胸腺选择的模型中选择性和可逆地抑制 Zap70 的催化活性，结果表明，CD4(+)CD8(+)胸腺细胞在超过 36 小时的时间内整合多个短暂的、依赖 Zap70 的信号，以达到正选择的累积阈值，而 1 小时的信号传递足以进行负选择。Zap70 活性的滴定导致正选择和负选择的逐渐减少，但并没有减少通过正选择的 OT-I 细胞整合的累积 TCR 信号，这表明即使在表达相同 TCR 并经历正选择的 CD4(+)CD8(+)胸腺细胞中，也存在异质性。
