Abstract: The invention relates to an in vitro quantative cell-based assay that uses a primary mouse cell model system permissive to viral vector infection and a quantitative high content image-based system for determining potency of a transgene-expressing viral vector drug product for lot disposition.

Abstract: Novel metalloproteases having thrombospondin domain(s) (MPTS proteins) and polypeptides related thereto, as well as nucleic acid compositions encoding the same, are provided. The subject polypeptide and nucleic acid compositions find use in a variety of applications, including diagnostic applications, therapeutic agent screening applications, as well as therapeutic applications for a variety of different conditions. Also provided are methods of treating disease conditions associated with aggrecanase activity, e.g. conditions characterized by the presence of aggrecan cleavage products, such as rheumatoid- and osteo-arthritis.