Fig. 4.
Importance of IL-2 for IL-4 production by naive cord blood T cells. CD4+CD45RO− cord blood T cells (5 × 105/ml) were cultured with P815/CD80 cells (5 × 105/ml) in the presence of anti-IL-4R MoAb (2.5 μg/ml) and anti-CD3 MoAb (UCHT1) at a concentration of 2 μg/ml. To block IL-2 activity, a neutralizing anti-IL-2 antibody (1 μg/ml) and anti-IL-2Rα (5 μg/ml) and anti-IL-2Rβ (2 μg/ml) MoAbs were added as indicated (a). Supernatants were collected after 72 h (a) or after 1, 3, 5, 7, 24 and 72 h (b) of culture and the IL-2 (b) and IL-4 (a,b) concentrations in the supernatants were determined by ELISA. The detection limit for IL-4 in these experiments (a) is represented by a horizontal black line. The results (mean ± s.e.m.) of three independent experiments (a) or one experiment (b) with different donors are shown.