Inhibition of γc function prevents IL-7–induced mFL and sFL expression in T lymphocytes.

T cells were cultured for 72 hours in the presence of IL-7 (15 ng/mL) and increasing concentrations of: (A) Anti-γc mAb CP.B8 or (B) Jak3 inhibitor tyrphostin AG490. Expression of mFL (gray bars) was analyzed by FACS, and sFL (black bars) by ELISA, and calculated as percent ± SEM of expression in the absence of the inhibitors after subtracting the amounts expressed spontaneously. In a control experiment, tyrphostin AG490 did not inhibit cell surface expression of γc (not shown).