Dolby N, Mehta V, Cook R G
Department of Microbiology and Immunology, Baylor College of Medicine, Houston, TX 77030.
Immunogenetics. 1990;32(6):380-8. doi: 10.1007/BF00241631.
The expression of thymus leukemia (TL) antigens and genes in thymocytes and activated T cells was examined by immunoprecipitation, flow cytometric, northern, and nuclear run-off transcription analyses. Cell surface forms of TL were detectable by immunoprecipitation on activated peripheral T cells from Tla haplotypes except Tla(b), in agreement with expression observed on thymocytes. Approximately 40%-50% of concanavalin A (Con A) or anti-CD3-activated T cells were TL+, with expression detected on both the CD4 and CD8 subsets by dual-color analysis. Activated T cells expressed detectable levels of TL mRNA 48 h after stimulation, but no TL transcripts were detectable in unstimulated splenocytes. However, TL mRNA expression in mature activated T cells did not precisely mimic thymocyte expression: the level of expression was considerably lower in activated T cells, and in most haplotypes the transcripts produced in activated T cells appeared to represent a subset of the transcripts produced in thymocytes. By run-off transcription assays in isolated nuclei, TL gene expression was detected in activated but not resting T cells indicating that lack of expression of TL in resting T cells is not due to message instability. These data demonstrate that TL genes are inducible and transcriptionally regulated.
通过免疫沉淀、流式细胞术、Northern印迹和细胞核延伸转录分析，检测胸腺细胞和活化T细胞中胸腺白血病（TL）抗原和基因的表达。除Tla(b)外，在来自Tla单倍型的活化外周T细胞上，通过免疫沉淀可检测到细胞表面形式的TL，这与在胸腺细胞上观察到的表达一致。约40%-50%的伴刀豆球蛋白A（Con A）或抗CD3活化的T细胞为TL阳性，通过双色分析在CD4和CD8亚群上均检测到表达。活化的T细胞在刺激后48小时表达可检测水平的TL mRNA，但在未刺激的脾细胞中未检测到TL转录本。然而，成熟活化T细胞中TL mRNA的表达并不完全模拟胸腺细胞的表达：活化T细胞中的表达水平明显较低，并且在大多数单倍型中，活化T细胞中产生的转录本似乎代表胸腺细胞中产生的转录本的一个子集。通过在分离细胞核中的延伸转录分析，在活化而非静止的T细胞中检测到TL基因表达，表明静止T细胞中TL表达的缺乏不是由于信息不稳定。这些数据表明TL基因是可诱导的且受转录调控。
