Figure 1
Lack of airway luminal antigen (Ag)-specific T cells in parenteral Bacillus Calmette–Guérin (BCG)-immunized animals before and after pulmonary mycobacterial challenge. (a) Mice were killed 9 weeks following BCG immunization and Ag-specific T cells in the bronchoalveolar lavage (BAL), lung interstitium, and spleen were examined. (b–d) Naïve non-immunized and BCG-immunized mice were challenged with Mycobacterium tuberculosis (M.tb) 9 weeks after BCG immunization, and killed at 5, 10, and 14 days post infection for T-cell analysis or at 5, 10, 14, and 28 days post infection for assessing the level of protection (infection) in the lung. Ag-specific T-cell responses were analyzed in the BAL (b) and lung interstitium (c). Lungs from infected mice were assessed for the level of protection (infection) at various time points post challenge (d). Data are expressed as mean values±s.e.m. of 4–5 mice/time/group, representative of 2–3 independent experiments. **P ≤ 0.005 compared with the indicated groups. IFN, interferon; CFU, colony-forming units.
