IL-7 upregulates the IL-2 and IFN-γ mRNA accumulation in activated human T lymphocytes. T cells were left unstimulated or stimulated with PHA or PHA plus anti-CD28 (aCD28) in the presence or absence of IL-7. Total RNA was isolated after 6 hours of stimulation. (A) Northern hybridizations with IL-2, IFN-γ, and 28S cDNA probes were performed. (B) mRNA levels were quantified using a PhosphorImaging system, and IL-2 and IFN-γ mRNA levels were normalized with respect to the 28S signal.