IL-2 secretion in total or subsets of PHA/PMA-stimulated PBMC-derived human T-lymphocytes was monitored and found to be largely due to CD4+CD8−cells. The presence and functional state of transcription factors (TF) was assessed by protein-DNA interaction assays and functional transactivation experiments in the Xenopts oocyte system, modulating IL-2 transcription by injection of proteins. The results reveal that CD4+CD8−cells contain both, functional silencer in their resting, and positive TF in their activated states while the CD4+CD8−group contains only non-functional positive TF. This demonstrates that the on/off switch of IL-2 transcription is based on the same mechanism in primary T-lymphocytes of mouse spleen and in peripheral human CD4+CD8−cells.
Generation of adult human T-cell progenitors for immunotherapeutic applications