During inflammation, leukocytes are recruited to target areas in response to chemokines. However, cessation of this response is important for tissue healing and wound repair. McQuibban et al. propose that matrix metalloproteinases (MMPs) are key effectors of down-regulating chemokine activity. When the chemokine monocyte chemoattractant protein (MCP)-3 is cleaved by the MMP gelatinase A, it is converted from a chemokine receptor agonist to an antagonist. This conversion blocks the response of leukocytes to a variety of chemoattractants that use the same receptors.
McQuibban, G.A., Gong, J.-H., Tam, E.M., McCulloch, C.A.G., Clark-Lewis, I., and Overall, C.M. (2000) Inflammation dampened by gelatinase A cleavage of monocyte chemoattractant protein-3. Science 289: 1202-1206. [Abstract] [Full Text]