Figure 1.

Overexpression of Tpl-2 induces IL-2 expression in EL4 and Jurkat cells. (A) IL-2 was measured by ELISA in culture supernatants of three clones of EL4 cells transfected stably with the carboxyl-terminally truncated Tpl-2 construct (Tpl-2tr) and two independent clones of EL4 cells transfected stably with the wild-type Tpl-2 construct (Tpl-2wt). Vector (pBabe) transfected cells secrete no IL-2. (B and C) EL4 and Jurkat cells were transiently transfected with Tpl-2 and carboxyl-terminally truncated Tpl-2 expression constructs. Thirty-six hours after transfection, empty vector-transfected control cells were stimulated with PMA plus ionomycin and cultured for an additional 8 h period. Culture supernatants were harvested and IL-2 was measured by ELISA.