Evidence for down-regulation of highly expressed TCR by CD4 and CD45 on non-selected CD4+CD8+ thymocytes.
Evidence for down-regulation of highly expressed TCR by CD4 and CD45 on non-selected CD4+CD8+ thymocytes.
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未选择的 CD4 CD8 胸腺细胞上的 CD4 和 CD45 下调高表达 TCR 的证据。
DOI：
10.1093/intimm/8.10.1529
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发表时间：
1996
影响因子：
4.4
通讯作者：
S. Habu
中科院分区：
文献类型：
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作者：
T. Sato;K. Hozumi;K. Kishihara;Y. Kametani;C. Sato;Y. Kumagai;T. Mak;S. Habu
如果未成熟的CD 4 + CD 8+双阳性（DP）胸腺细胞表达与低亲和力的胸腺配体反应的TCR，则它们被积极选择用于进一步发育。然而，大多数DP胸腺细胞表达低TCR水平。这种低水平的TCR可能不足以识别胸腺配体。为了了解DP胸腺细胞上TCR低表达的基础，我们使用TCR转基因（TCR-Tg）小鼠测定了其发育的各个阶段的TCR表达密度。我们发现，TCR的表达是高的胸腺细胞，最近过渡到DP阶段，但随后逐渐下降DP细胞，如果他们不选择TCR与MHC分子的相互作用。然而，在阳性选择的DP细胞和从CD 45缺陷小鼠或从接受抗CD 4 mAb的小鼠获得的非选择的DP细胞中未观察到这种TCR抑制。这些发现表明，在DP阶段的一次高表达的TCR被非选择性胸腺细胞上的CD 45和/或CD 4抑制。此外，TCR抑制被TCR介导的信号阻止。在阳性选择的DP胸腺细胞上维持高TCR水平可能有助于它们的选择。
Immature CD4+CD8+ double-positive (DP) thymocytes are positively selected for further development if they express TCR reacting with thymic ligands of low affinity. However, the majority of DP thymocytes express low TCR levels. This low level of TCR may be insufficient to recognize thymic ligands. To understand the basis for the low expression of TCR on DP thymocytes, we determined the density of TCR expression at various stages of their development using TCR transgenic (TCR-Tg) mice. We found that TCR expression was high in the thymocytes that had recently transited into the DP stage but then gradually decreased on DP cells if they were not selected by TCR interaction with MHC molecules. However, such TCR suppression was not observed in positively selected DP cells and in the non-selected DP cells obtained from CD45 deficient mice or from mice receiving anti-CD4 mAb. These findings suggest that the once highly expressed TCR at the DP stage is suppressed by CD45 and/or CD4 on non-selected thymocytes. Furthermore, TCR suppression is prevented by TCR-mediated signals. The maintenance of high TCR levels on positively selected DP thymocytes may facilitate their selection.
转基因小鼠中不依赖 CD8 的 T 细胞成熟的证据。
DOI：
--
发表时间：
1990
期刊：
Journal of immunology (Baltimore, Md. : 1950)
影响因子：
--
作者：
Russell,JH;Meleedy-Rey,P;McCulley,DE;Sha,WC;Nelson,CA;Loh,DY
通讯作者：
Loh,DY
CD4 8- 和 CD4-8 成熟胸腺细胞需要不同的选择后处理才能最终发育。
DOI：
--
发表时间：
1993
期刊：
Journal of immunology (Baltimore, Md. : 1950)
影响因子：
--
作者：
Petrie,HT;Strasser,A;Harris,AW;Hugo,P;Shortman,K
通讯作者：
Shortman,K