Expression of the human Cathepsin L inhibitor hurpin in mice: skin alterations and increased carcinogenesis.

The serine protease inhibitor (serpin) hurpin (serpin B13) is a cross class-specific inhibitor of the cysteine protease Cathepsin (Cat) L. Cat L is involved in lysosomal protein degradation, hair follicle morphogenesis, epidermal differentiation and epitope generation of antigens. Hurpin is a 44 kDa protein which is expressed predominantly in epidermal cells.

S100A15, an antimicrobial protein of the skin: regulation by E. coli through Toll-like receptor 4.

E. coli is a gram-negative bacterium rarely found on human skin. We investigated whether direct interaction of E.