expression of human proteinase 3 in chinese hamster ovary cells (cho-cells)

proteinase 3(pr3) is a human polymorphonuclear leukocyte serine proteinase and is the main target antigen for antineutrophil cytoplasmic antibodies (anca) found in wegener's granulomatosis (wg). we developed a stable expression system for conformationally intact recombinant pr3 (rpr3) in chinese hamster ovary cells (cho-cells). the part of pr3 cdna that encoded the active form of pr3 was selected by using appropriate primers, and a signal sequence was also added in front ofpr3 edna. the signal sequencepr3 (s-pr3) was cloned into the pme 18 expression vector and the result product was electroporated into e. coli (dh5 a strain). after isolation and purification, the presence of pmei8-s-pr3 was confirmed by using appropriate restriction endonuclease and agarose gel electrophoresis. the pmei8- s-pr3 was electroporated with cho-cells and the presence of rpr3 was tested in culture medium after 10 days. there was 12 ng/ml rpr3 in culture medium that had activity and was recognized by anca in elisa.