The tyrosine phosphatase SHP-1 influences thymocyte selection by setting TCR signaling thresholds
The tyrosine phosphatase SHP-1 influences thymocyte selection by setting TCR signaling thresholds
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DOI：
10.1093/intimm/11.12.1999
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发表时间：
1999-12-01
影响因子：
4.4
通讯作者：
Lorenz, U
中科院分区：
文献类型：
--
作者：
Carter, JD;Neel, BG;Lorenz, U
TCR信号强度的调节决定了胸腺细胞发育中阳性和阴性选择的结果。先前的研究已经证明，SHP-1在决定TCR的信号强度中起作用。在这里，我们已经采取了遗传方法来测试SHP-1是否在胸腺中的T细胞选择中发挥作用。在BYDP杂交瘤细胞系中表达SHP-1的显性阴性突变体的实验证实了SHP-1以细胞自主的方式调节TCR信号传导，并表明Lck是其靶点之一。为了研究SHP-1在T细胞发育中的作用，我们将卵清蛋白特异性DO11.10 TCR转基因杂交到缺乏SHP-1表达的蛾背景上。对这些杂交后代的分析提供了SHP-1.调节胸腺细胞选择：（i）流式细胞术分析揭示了me/me背景中胸腺细胞亚群百分比的改变;（ii）离体缺失实验表明，与+/+：Tg胸腺细胞相比，me/me：Tg胸腺细胞在较低浓度的OVA肽下经历负选择;和（iii）离体增殖分析表明，me/me：Tg胸腺细胞对特异性OVA肽的刺激超敏感。我们观察到SHP-1的缺乏导致TCR转基因胸腺细胞的选择改变，这表明SHP-1在体内调节TOP介导的信号的强度，进而有助于设定胸腺细胞选择的阈值。
Modulation of the strength of signals from the TCR determines the outcome of positive and negative selection in thymocyte development. Previous studies have demonstrated that SHP-1 plays a role in determining signal strength from the TCR. Here, we have taken a genetic approach to test whether SHP-1 plays a role in T cell selection in the thymus. Experiments in which a dominant negative mutant of SHP-1 was expressed in the BYDP hybridoma cell line confirmed that SHP-1 regulated TCR signaling in a cell-autonomous manner and suggested that Lck is one of its targets. To examine the role of SHP-1 in T cell development, we crossed the ovalbumin-specific DO11.10 TCR transgene onto the motheaten background, which lacks SHP-1 expression. Analysis of the progeny of these crosses provided evidence that SHP-1. regulates thymocyte selection: (i) flow cytometric analyses revealed alterations in the percentages of thymocyte subpopulations in the me/me background; (ii) ex vivo deletion experiments demonstrated that me/me:Tg thymocytes undergo negative selection at lower concentrations of OVA peptide compared to +/+:Tg thymocytes; and (iii) ex vivo proliferation analyses indicated that me/me:Tg thymocytes were hyper-sensitive to stimulation by the specific OVA peptide. Our observation that the absence of SHP-1 leads to altered selection of TCR transgenic thymocytes demonstrates that SHP-1 regulates the strength of TOP-mediated signals in vivo and, in turn, helps to set the threshold for thymocyte selection.