Fig. 4. Alternatively activated BMDMs produce more M1 mRNA than classically activated macrophages. BMDMs were activated with IFN-γ (classically activated) or IL-4 (alternatively active) and infected with 10 p.f.u. A/WSN/33 per cell (WSN). At 48 h p.i., M1 mRNA levels were measured by qRT-PCR. ***P < 0.001.