FIGURE 6.

KGF treatment of MLE-15 cells results in a decrease in M. tuberculosis burden in co-cultured RAW cells and induces GM-CSF production. To determine the mechanism of KGF-enhanced M. tuberculosis clearance, MLE-15 cells plated in the lower well of transwell plates were pretreated with KGF (100 ng/ml) or medium only overnight. RAW cells infected with M. tuberculosis were then added to the upper well. A, after 5 days of co-culture, the RAW cells were harvested, lysed, and plated onto 7H11 Middlebrook agar plates, and cfu were quantified. Data are for n = 4 experiments; p < 0.05. B, the levels of GM-CSF in culture supernatants were measured by ELISA on culture day 5. Results are shown as the mean ± S.D. (error bars) and are representative of three independent experiments. p < 0.05 for comparison of columns A and C, A and D, and B and D.