Antibody targeting of Cathepsin S induces antibody-dependent cellular cytotoxicity.

Background: Proteolytic enzymes have been implicated in driving tumor progression by means of their cancer cell microenvironment activity where they promote proliferation, differentiation, apoptosis, migration, and invasion. Therapeutic strategies have focused on attenuating their activity using small molecule inhibitors, but the association of proteases with the cell surface during cancer progression opens up the possibility of targeting these using antibody dependent cellular cytotoxicity (ADCC). Cathepsin S is a lysosomal cysteine protease that promotes the growth and invasion of tumour and endothelial cells during cancer progression.

Expression and purification of diagnostically sensitive mycobacterial (Mycobacterium bovis) antigens and profiling of their humoral immune response in a rabbit model.

The incidence of bovine tuberculosis (bTB) is increasingly giving rise to large economic losses in the agricultural industry. The current methods used for detection and control of bTB (skin test and interferon-gamma) lack desired sensitivity and specificity. Therefore, the development of a rapid and reliable bTB serological based assay is urgently required.

Production of recombinant proteins in Escherichia coli using an N-terminal tag derived from sortase.

The use of Escherichia coli protein expression systems has many benefits, including the ease of propagation, amounts of protein that can be generated and cost. However, this host has some drawbacks due to difficulties in the production of soluble foreign proteins with their alternate codon usage bias, reductive cytoplasmic environment and lack of complex post-translational modifications. We have designed a novel fusion protein tag derived from the sequence of sortase (SrtA) which we have named Solubility 'eNhancing'Ubiquitous Tag (SNUT).

Multiplex immunoassay for serological diagnosis of Mycobacterium bovis infection in cattle.

Efforts to develop a better diagnostic assay for bovine tuberculosis have shown that the sensitivity and specificity of an assay can be improved by the use of two or more antigens. As reported here, we developed a multiplex chemiluminescent immunoassay that can simultaneously detect antibody activity to 25 antigens in a single well in a 96-well plate array format. The chemiluminescent signal is captured with a digital imaging system and analyzed with a macro program that tracks each serum for its pattern of antibody activity for Mycobacterium bovis antigens.

Recombinant cathepsin S propeptide attenuates cell invasion by inhibition of cathepsin L-like proteases in tumor microenvironment.

Human cathepsin L along with cathepsin S, K, and V are collectively known as cathepsin L-like proteases due to their high homology. The overexpression and aberrant activity of each of these proteases has been implicated in tumorigenesis. These proteases contain propeptide domains that can potently inhibit both their cognate protease and other proteases within the cathepsin L-like subfamily.

Inhibition of cathepsin L-like proteases by cathepsin V propeptide.

The N-terminal propeptide domains of several cathepsin L-like cysteine proteases have been shown to possess potent inhibitory activity. Here we report the first kinetic characterisation of the inhibition properties of the cathepsin V propeptide (CatV PP). Using a facile recombinant approach we demonstrate expression, purification and evaluation of the CatV PP.