Chemokine and cytokine processing by matrix metalloproteinases and its effect on leukocyte migration and inflammation.

The action of matrix metalloproteinases (MMPs) was originally believed to be restricted to degradation of the extracellular matrix; however, in recent years, it has become evident that these proteases can modify many nonmatrix substrates, such as cytokines and chemokines. The use of MMP-deficient animals has revealed that these proteases can indeed influence the progression of various inflammatory processes. This review aims to provide the reader with a concise overview of these novel MMP functions in relation to leukocyte migration.