IL-7 is constitutively produced by dendritic cell (DC) and uniquely upregulated upon CD40L/IFN-γ activation. DCs were generated and activated as described in ‘Dendritic cell generation and activation.’ Supernatants harvested from immature DC (iDC) and mature DC (mDC) 48h after activation were assayed by enzyme-linked immunosorbent assay (ELISA) for production of (a) IL-12 and (b) IL-7. P-values were obtained with the Student’s t-test; P-values <0.05 are significant (n=27). Horizontal bars represent mean values ± s.e.m. Activation of DC with CD40L-IFN-γ and/or TLR 4/7/8 agonists, (c) Supernatants harvested from iDC and CD40L-IFN-γ, TLR4 (ultrapure LPS, 500 ng ml−1) and/or TLR 7/8 (3M-007, 5 µg ml−1)-activated DC (48h) were assayed by ELISA for production of IL-7. (d) Supernatants harvested from iDC, CD40L, IFN-γ and CD40L-IFN-γ-activated DC (48h) were assayed by ELISA for production of IL-7. P-values were obtained with the repeated measure analysis of variance (ANOVA) followed by Tukey’s analysis; P-values <0.05 are significant (n=6). Horizontal bars represent mean values ± s.e.m.