IL-7 increases the IL-2–gene transcription rate in activated human T lymphocytes. Nuclei were isolated from unstimulated T cells or T cells stimulated for 3 hours with PHA plus anti-CD28 (aCD28) in the presence or absence of IL-7, and the transcription was allowed to proceed for another 20 minutes in the presence of 32P-labeled UTP. (A) Nuclear RNA was isolated and hybridized to a membrane containing linearized cDNAs for IL-2 and GAPDH. The pCAT3-enhancer plasmid was included as a negative control. (B) Transcription rates were quantified using a PhosphorImaging system, and IL-2 transcription rates were normalized with respect to the GAPDH signal, as described in the Materials and Methods section. The results are expressed as relative transcription rate compared to the PHA/anti-CD28–induced IL-2 transcription rate, which was set at 1.
