Fig. 5.

Contribution of N₂O₃ to the nitrosative capacity of IFNγ-primed macrophages. The ability of Hmp to diminish N-nitrosation by macrophages from C57BL/6 and gp91phox-deficient mice was studied 12 h after infection by following the generation of triazol (NAT) from DAN. Selected groups of macrophages were treated in vitro with 200 U/ml IFNγ 12-16 h before infection with wild-type (WT) or ΔhmpA-mutant Salmonella. To increase sensitivity of the assay, NAT formation was monitored in macrophages cultured in 24 well plates at a density of 5×10⁵ cells/well and challenged with hmpA-proficient or -deficient Salmonella at an MOI of 5. After 12 h of infection, macrophages were incubated for 1 h in MEM⁺ medium supplemented with 200 μM DAN and 6 μg/ml gentamycin and the amount of NAT formed measured as above.