Fig. 5.

Effect of endogenous IL-4 on cytokine production by human naive CD4⁺ T cells. Resting CD4⁺CD45RO⁻ adult T cells or CD4⁺CD45RO⁻ cord blood T cells at a concentration of 5 × 10⁵ T cells in a 1-ml volume were cultured with P815/CD80 cells (5 × 10⁵/ml), in the presence or absence of anti-IL-4R MoAb (2.5 μg/ml). Anti-CD3 MoAb (UCHT1) was added at a concentration of 2 μg/ml. Supernatants were collected after 72 h of culture and the IFN-γ, IL-5 and IL-13 concentrations in the supernatants were determined by ELISA. The results (mean ± s.e.m.) of seven independent experiments on different adult non-atopic donors and seven independent experiments with different cord blood samples are shown. *P < 0.05; **P < 0.01.