Figure 2.

Respiratory mucosal immunotherapy controls bacterial infection in the lung after antibiotic cessation. (A) Experimental schema. At 4 weeks post-Mycobacterium tuberculosis (M.tb) infection, mice were started on oral antibiotic therapy. Groups of mice were treated for 4 (antibiotics alone [ABx] cessation) or 8 (ABx) weeks. In a set of animals, antibiotic therapy was ceased after 4 weeks and a single dose of AdCh68Ag85A was administered intranasally (ABx cessation+I.N.Vac.). All mice were sacrificed 12 weeks postinfection for assessment of tuberculosis disease indices. (B) Bar graph comparing bacterial burden in the lungs of various groups of mice. (C) Representative micrographs of lung sections stained with hematoxylin and eosin, comparing the extent of lung inflammation and granulomatous lesions. Scale bar indicates 500 µm. Data are expressed as the mean ± standard error of the mean of 6–10 mice/group. CFU, colony-forming units.