FIG 1.

Susceptibility to MAC is regulated by Nrf2. (A) Survival of wild-type and Nrf2^−/− mice after intranasal inoculation of 1 × 10⁷ CFU of MAC bacteria or saline (n = 20 in each group). (B) Representative photographs of the lungs from wild-type and Nrf2^−/− mice 2, 4, and 8 months after intranasal inoculation of 1 × 10⁷ CFU of MAC. Ziehl-Neelsen staining was used. Magnification, ×400. (Insets) Acid-fast bacilli at higher magnifications. (C) Mycobacterial outgrowth in the lungs, spleens, and livers of wild-type and Nrf2^−/− mice 2 months after intranasal inoculation of 1 × 10⁷ CFU of MAC. The results are expressed as CFU per organ. The experiments were performed in duplicate with eight mice in each group. Differences between Nrf2^−/− mice and wild-type mice after MAC infection were significant (#, P < 0.05). Data are means and SEM.