Objective   To obtain Chinese hamster ovary  (CHO) cell lines that stably express a targeting complement inhibitor CR2-CD59.    Methods   The recombinant plasmid PEE14.1-CR2-CD59 was constructed by cloning the DNA fragment CR2-CD59 into plasmid PEE14.1

and the obtained plasmid was transfected into CHO cells by FuGENE 6. The clones with stable high expression of target fragment were selected by methionine sulfoximine (MSX)

the expression of CR2-CD59 was analyzed by ELISA

SDS-PAGE and Western blotting analysis.    Results   Several stable expression clones were obtained

and CR2-CD59 was highly expressed in the secret form in CHO cells. SDS-PAGE analysis showed that the molecular weight of the recombined protein CR2-CD59 was consistent with the predicted one. ELISA and Western blotting results revealed that the CR2-CD59 could react with both anti-human CR2 and anti-human CD59 polyclonal antibodies. Compared with serum-containing medium

the protein was highly expressed in serum-free medium (P0.05).    Conclusion   Targeting complement inhibitor CR2-CD59 is successfully expressed in CHO cells.