Editor's Summary
30 July 2009
Antibacterial macrophages
Normal physiologic roles for many of the matrix metalloproteinases (MMPs), an extensive family of zinc-dependent endopeptidases, remain poorly understood. Matrix metalloproteinase-12 (MMP-12, also known as macrophage elastase) is now shown to possess direct antimicrobial activity against Gram-positive and Gram-negative bacteria. This function of MMP-12 is associated with the carboxy-terminal domain of the molecule, rather than its catalytic site. And surprisingly — since MMPs are in the main active within the extracellular space — its antimicrobial activity is exerted within the cell. This work also highlights a role for macrophages in the earliest stages of acute bacterial infection, more familiarly regarded as the province of neutrophils.
Letter: Macrophage elastase kills bacteria within murine macrophages
A. McGarry Houghton, William O. Hartzell, Clinton S. Robbins, F. Xavier Gomis-Rüth & Steven D. Shapiro
doi:10.1038/nature08181
