Fig. 3

ESAT-6 inhibits apoptosis of THP-1（A）macrophages via TLR2-Caspase 9/Caspase 3. A ESAT-6 inhibits apoptosis of THP-1 macrophages via TLR2. H37Ra was infected with THP-1(A) for one hour then treated with blocking anti-TLR2 antibody (AB9100, USA) for 30 min, and finally treated with ESAT-6 (5 μg/ml) for 24 h. Macrophages apoptosis was detected by Annexin V FITC/PI in flow cytometry. B Quantitative data of apoptosis in ESAT-6 and/or mycobacteria/AB9100 stimulated macrophages are shown. C, D ESAT-6 inhibits apoptosis of THP-1 macrophages via Caspase 9/Caspase3. The cells with the same treatment were analyzed by Western blotting for Casepase3, cleaved-Caspase3, Caspase9, and cleaved-Caspase9 protein levels. Densitometric quantification of representative blots relative to β-actin levels. Results are shown as mean ± SEM. *p < 0.05,**p < 0.01, and ***p < 0.001, respectively, compared with the M. tb group