Figure 7.

Treatment with interferon-γ/prostaglandin E₂ (IFN-γ/PGE₂) circumvents the requirement for tumour necrosis factor receptor 1 (TNFR1) signalling in the generation of regulatory macrophages. Wild-type (WT) or TNFR1^−/− bone-marrow-derived macrophages (BM-Mϕ) were incubated in PTFE-coated plates for 72 hr in the presence of recombinant IFN-γ (100 U/ml), recombinant PGE₂ (1 ng/ml), or both together. After 72 hr, washed cells were co-cultured with OT-II T cells in the presence of OVA peptide (100 μg/ml) for a further 72 hr when T-cell proliferation (a) and nitric oxide (NO) elicited (b) were measured. Pre-treatment with IFN-γ and PGE₂ together produces TNFR1^−/− Mϕ that suppress proliferation. These data are representative of three independent experiments.