Fig 4. Increased IL-10 production by the lung cells of B cell-deficient μMT mice during chronic infection with M. tuberculosis.

Mice were aerogenically infected with a low dose (100 CFU) of M. tuberculosis Erdman. Ex vivo IL-10 production by lung cells isolated from B cell-deficient μMT and WT control mice was evaluated at 12 weeks (A) and 24 weeks (B) after infection. Single-cell suspension of lung cells were cultured in complete RPMI with or without 10 μg/ml of PPD (Statens Serum Institute, Copenhagen) at 1.0 x 10⁷ cells per ml. After 48 hours of culture, supernatants were collected and subjected to detection of IL-10 as described in “Materials and Methods” section. The results revealed that the levels of expression of lung IL-10 in tuberculous μMT mice are enhanced compared to that observed in WT animals. The data are depicted as mean ± SEM. The results shown in this figure are representative of two independent experiments; n = 4 to 5 mice per group per time interval.