Figure 6
Accelerated and enhanced immune protection from pulmonary Mycobacterium tuberculosis (M.tb) challenge by culture filtrate (CF)–mediated installation of airway luminal T cells in parenteral Bacillus Calmette–Guérin (BCG)-immunized hosts. (a) Experimental schema. (b, c) The levels of immune protection in the lung (bacterial colony-forming units (CFU) burden) were assessed either 2 weeks (b) or 4 weeks (c) post-M.tb challenge. Data are expressed as mean values±s.e.m. of 5–6 mice per group, representative of two independent experiments. (d–f) The extent of lung immunohistopathology was assessed at 4 weeks post-M.tb challenge in naïve non-immunized (d), parenteral BCG immunization alone (e) and parenteral BCG-immunized/CF–treated (f) mice. Each hematoxylin and eosin –stained histomicrograph is representative of 5–6 mice per group (× 4 magnification). *P ≤ 0.05, **P ≤ 0.005 compared with the indicated groups. SAC, sacrifice; s.c., subcutaneously.
