Format

Send to

Choose Destination
Nat Immunol. 2008 Oct;9(10):1189-97. doi: 10.1038/ni.1654. Epub 2008 Sep 14.

Mycobacterium tuberculosis blocks crosslinking of annexin-1 and apoptotic envelope formation on infected macrophages to maintain virulence.

Author information

1
Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.

Abstract

Macrophages infected with attenuated Mycobacterium tuberculosis strain H37Ra become apoptotic, which limits bacterial replication and facilitates antigen presentation. Here we demonstrate that cells infected with H37Ra became apoptotic after the formation of an apoptotic envelope on their surface was complete. This process required exposure of phosphatidylserine on the cell surface, followed by deposition of the phospholipid-binding protein annexin-1 and then transglutaminase-mediated crosslinking of annexin-1 through its amino-terminal domain. In macrophages infected with the virulent strain H37Rv, in contrast, the amino-terminal domain of annexin-1 was removed by proteolysis, thus preventing completion of the apoptotic envelope, which resulted in macrophage death by necrosis. Virulent M. tuberculosis therefore avoids the host defense system by blocking formation of the apoptotic envelope, which leads to macrophage necrosis and dissemination of infection in the lung.

PMID:
18794848
PMCID:
PMC5351782
DOI:
10.1038/ni.1654
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center