Pathogenic potentials of bacterial proteases

Abstract

Six separate molecular mechanisms for pathogenesis attributed to bacterial proteases are described. (I). Enhancements of vascular permeability and edema formation which result from the activation of kinin generating cascade such as Hageman factor by the proteases. (II). Degradation of defense oriented proteins including IgG and IgA as well as destruction of structural matrices such as fibronectin, proteoglycan and collagen. (III). Inactivation of complement system and generated chemotactic factor from C3 and C5. (IV). Degradation of regulatory plasma protease inhibitors (serpins) including α 1protease inhibitor, α 2-macroglobulin (α 2M), C1-esterase inhibitor, α 2-antiplasmin and antithrombin-III. (V). The protease forms a transitory stable enzyme/inhibitor(α 2M) complex. It binds to and internalizes into the cells which possess α 2M-receptor such as fibroblasts via the α 2M-receptor, and the protease activity is regenerated in cells, and subsequently intracellular integrity is destroyed resulting in cell killing. (VI). The serratial 56 kDa (56K) protease is found to potential viral yield 100 fold more when influenza virus infected mice were subjected to administrations of this protease intranasally. This results in rapid and much elevated lethality.