Figure 3. Airway adoptive transfer of M2 macrophages increases the resistance to M. tuberculosis infection.

Thirty days after M. tuberculosis infection, mice underwent M2 cell transfer (2 × 10⁶ cells) by the intra-tracheal route. The CFU count (a) and Fizz1 and iNOS gene expression (b) were evaluated 8 days post-cell transfer. The data represent the mean ± s.e.m. from 2 independent experiments (n = 10–18). CFSE⁺ M2 macrophages evaluated in the lungs by flow cytometry 24 hours post-cell transfer (c). BMDMs were differentiated into M1 or M2 macrophages. The M1 and M2 macrophages were infected with M. tuberculosis (MOI 1), and after 4 hours, phagocytic activity was evaluated (d). Infected M2 macrophages were treated (+) or not (−) with IFN-γ (200 ng/mL). Untreated infected M1 macrophages (−) were used as controls. After 5 days, the cells were lysed, and serial dilutions were plated for a CFU assay (e). The data represent the mean ± s.e.m. from 2 independent experiments (n = 4–6) *p < 0.05.