Apoptosis rate of and changes over time in macrophages infected with Mycobacterium tuberculosis with different levels of virulence tested with flow cytometry

Objective To compare the rate of apoptosis of macrophages infected with H37Rv and BCG using flow cytometry.Methods RAW264.7 cells were infected with H37Rv and BCG strains.Flow cytometry was used to detect the rate of macrophage apoptosis 1 h,3 h,6 h,and 12 h after infection.Changes over time in the rate of apoptosis of infected macrophages were analyzed.Results H37Rv and BCG increased the rate of macrophage apoptosis.Apoptosis increased markedly 1h and 12 h after infection.There were significant differences in the rate of apoptosis of macrophages infected with BCG and macrophages infected with H37Rv(P0.05).Conclusion M.tuberculosis induced the apoptosis of macrophages.The rate of apoptosis correlated with the virulence of the strain of M.tuberculosis.Apoptosis of macrophages infected with the less virulent M.tuberculosis soon increased markedly.