Fig. 4.

AlbGM-CSF administration enhances lung bacillary control during chronic TB. a After 28 days of low-dose aerosol Mtb exposure, 0.375 µmol of albGM-CSF or GM-CSF was given by retro-orbital injection once. Four weeks after injection, the lung bacillary colony-forming units (CFUs) were determined (n = 4 for the untreated and albGM-CSF groups, n = 5 for the GM-CSF and INH groups). b In a separate experiment, either albGM-CSF or GM-CSF was given by subcutaneous injection to mice once weekly for 4 weeks after 28 days of low-dose aerosol Mtb exposure. Four weeks after the first injection, the lung CFUs were determined. All data are represented as the mean log₁₀ CFU ± SEM, n = 5, *p < 0.05; NS not significant. After four subcutaneous injections, the lung cells were collected from each group and then stimulated with ESAT6 (c) or TB10.4 (d) peptides overnight. Antigen-specific CD4⁺ (c) or CD8⁺ (d) T cells were analyzed by intracellular IFNγ release assay and flow cytometry. All data are represented as the mean, n = 4, *p < 0.05