FIG. 5.

Spleen IFN-γ mRNA after M. avium infection as determined by RT-PCR. Total RNA was extracted from spleen tissue at 4 and 8 weeks after infection. Murine IFN-γ mRNA was amplified by RT-PCR. PCR products were subjected to electrophoresis on a 3% agarose gel and stained with ethidium bromide. Each lane shows the 243-bp IFN-γ PCR product from a single mouse. PCR products from mice vaccinated with pCMV4.65 (lanes 1 to 3), p65K-EGFP (lanes 4 to 6), BCG (lanes 7 to 9), and saline (lanes 10-12) are shown. IFN-γ mRNA was increased at 4 weeks in all groups and declined toward baseline levels at 8 weeks. There were no significant differences among the groups.