Figure 1.

Bacteria increase HIF-1α protein expression and stimulate HIF-1α transcriptional activity. (A and B) Macrophages were incubated under hypoxia (0.1%) or with GAS, MRSA, S. typhimurium (ST), or P. aeruginosa (PA) at an MOI equal to 5–10 under normoxic conditions for 4 hours. Expression of HIF-1α was normalized to β-actin levels and quantified with ImageQuantTL software (Amersham Biosciences). (C) HRE-luciferase BM-derived macrophages were incubated either with GAS or heat-inactivated GAS at an MOI equal to 5–10 under hypoxia (1%) or with the addition of mimosine (800 μM), desferrioxamine mesylate (150 μM), or CoCl₂ (150 μM) for 18 hours. Statistical analyses were performed using unpaired Student’s t test. **P < 0.01; ***P < 0.001.