ABSTRACT
Apoptosis is an important host defense mechanism against mycobacterial infection. Recent reports suggest that links between apoptosis and endoplasmic reticulum (ER) stress are critical for the regulation of mycobacterial survival; however, the exact regulatory mechanisms are not well known. In this study, we isolated 20 Mycobacterium tuberculosis (Mtb) clinical strains from Korean patients and examined ER stress-mediated apoptosis in Mtb-infected macrophages. Most Mtb strains increased the rates of apoptosis and production of ER stress-sensing molecules in mouse macrophages, similar to Mtb H37Rv infection. Moreover, the intracellular survival of Mtb clinical isolates in macrophages was similar to that of H37Rv. Our data suggest that infection with Mtb downregulated MCP-1 and MCPIP. The regulation of MCPIP may decrease ROS production, leading to a reduction in ER stress-mediated apoptosis.