DC population in BM culture is modulated by TNF-TNFR1 signaling.

BM cells (1 × 10⁶ cells/mL) from either wt or TNF/LTα/LTβ^−/− mice were cultured with GM-CSF and IL-4 for 9 days. In panels A-C, rTNF was added to some wells of TNF/LTα/LTβ^−/− BM culture on day 0 at 10 ng/mL (A) or at various concentrations (B) or at 10 ng/mL on various days (C). In panel D, either anti-TNF (1 μg/mL) or blocking anti-TNFR1 (5 μg/mL) antibodies were added to wild-type BM cultures at the indicated time points. Cells were collected on day 9 and stained with FITC-conjugated anti–I-A^b mAb and PE-conjugated anti-CD11c mAb. Ratios of CD11c and I-A^b–positive cells are presented as a percent of wt (B). In panel B, data from 3 experiments are shown, *P < .05 compared with other concentrations of rTNF. Panels C and D show single representative experiments.