DS-PB-00380 recognizes an epitope located within the internal region of human Caspase5, a 47kDa cysteine protease, otherwise known as ICH3. Caspase5 has been shown to be expressed at higher levels in the colon, lung, spleen, small intestine and by peripheral blood lymphocytes. Caspase5 is a member of a growing number of inflammatory caspases belonging to the Caspase1 (ICEtype) subfamily, which require proteolytic processing of their inactive precursor into smaller active subunits. Unlike Caspase1, Caspase5 is not directly responsible for the activation of IL1Beta from the proIL1Beta precursor, but the presence of Caspase5 does appear to enhance the processing of IL1Beta. The in vivo expression of Caspase5 is elevated by Lipopolysaccharide (LPS) and gene expression is also increased by Interferon gamma (IFNg). In vitro studies have shown cleavage of Caspase5 by the serine protease Granzyme B, which plays a major role in Cytotoxic T lymphocyte (CTL)induced apoptosis (1).
Antisera to human Caspase-5 were raised by repeated immunisation of rabbits with highly purified antigen. Purified IgG was prepared by affinity chromatography.