Kinnon C, McGuire K L, Rothenberg E V
Division of Biology, California Institute of Technology, Pasadena.
Eur J Immunol. 1987 Sep;17(9):1265-9. doi: 10.1002/eji.1830170908.
Immature thymocytes that lack both Lyt-2 (CD8) and L3T4 (CD4) expression can respond rapidly to stimulation with phorbol ester and calcium ionophore by expressing some gene products characteristic of mature, activated T cells. Here we studied the effect of such short-term stimulation on the number of copies per cell of RNA for components of the T cell receptor complex. Although, upon stimulation, mRNAs for T cell receptor beta chain accumulated to higher levels, the cells did not rapidly increase their expression of alpha-chain transcripts from rearranged or germ-line genes. Transcripts from the C gamma 1 (C gamma 13.4) and C gamma 2 (C gamma 10.5) genes were differentially regulated. The rarer C gamma 1 transcripts were strongly induced, while the initially abundant C gamma 2 transcripts showed a modest decrease in transcripts per cell within 24 h. Thus, the ratio of these two transcripts could be shifted dramatically prior to any significant change in the cellular composition of the population. These results suggest regulatory processes that may contribute to the observed expression of gamma products in vitro or in normal development.
缺乏Lyt-2（CD8）和L3T4（CD4）表达的未成熟胸腺细胞，通过表达一些成熟活化T细胞特有的基因产物，能够对佛波酯和钙离子载体的刺激迅速做出反应。在此，我们研究了这种短期刺激对T细胞受体复合物各组分RNA每个细胞拷贝数的影响。尽管在刺激后，T细胞受体β链的mRNA积累到更高水平，但细胞并未迅速增加重排或种系基因α链转录本的表达。来自Cγ1（Cγ13.4）和Cγ2（Cγ10.5）基因的转录本受到不同的调控。较罕见的Cγ1转录本被强烈诱导，而最初丰富的Cγ2转录本在24小时内每个细胞的转录本出现适度下降。因此，在群体细胞组成发生任何显著变化之前，这两种转录本的比例可能会发生显著改变。这些结果提示了一些调控过程，这些过程可能有助于在体外或正常发育过程中观察到的γ产物的表达。
