Endo-lysosomal proteases in antigen presentation.

Endo-lysosomal proteases have long been attractive, yet elusive, targets for medicinal chemistry. They have found to play key roles in health and disease; with protease under- and over-activity having been implicated in cancer, osteoporosis and Alzheimer's disease. Here we will discuss their role in the adaptive immune response. The crucial roles of these enzymes multiple processes in antigen presentation will be discussed: from activating MHC-II receptors, to the production of epitopes from antigens and the activation of Toll-like receptors. The early efforts at pharmacological interventions in these pathways will also be discussed.