Figure 7.

Lung mRNA for the Type 1 cytokine IFN-γ at 7 days pi. Real-time RT-PCR of mRNA from lung tissue harvested at 3, 5, 7 or 20 days pi using primers for Type 1 markers iNOS, IL-12p40, TNF-α, and IFN-γ were largely negative. For example, no iNOS nor IL-12p40 was detected in any mice, and although TNF-α was detected at low levels, its expression did not differ among groups of mice. At 7 days pi, however, IFN-γ was significantly upregulated in all mice with Pcc infection, with or without Nb co-infection, as depicted here. Data are expressed as percentage of a positive control sample (peritoneal macrophages of a thioglycolate-injected mouse [10]). Mean ± SEM from a representative experiment with 4-9 mice per group per timepoint are shown.