Production methods of two specific biologically active fusion protein in mammalian cells and expression vector encoding the bispecific fusion protein

摘要

The present invention provides an expression vector encoding bispecific fusion protein. In one embodiment the expression vector encodes a monospecific fusion protein, which vector comprises a recombinant monospecific single chain cassette comprising a DNA sequence encoding a first binding domain capable of binding a cell surface antigen. The expression vector encodes a bispecific fusion protein, which vector comprises a recombinant bispecific single chain cassette comprising a DNA sequence encoding a first binding domain capable of binding a cell surface antigen and a DNA sequence encoding a second binding domain capable of binding a cell surface antigen, each domain capable of binding a different antigen. The present invention also provides a method for producing a biologically active bispecific fusion protein in a mammalian cell. This method comprises: (a) transfecting the mammalian cell with the recombinant expression vector of the invention; (b) culturing the mammalian cell so transfected in step (a); and (c) recovering the biologically active bispecific fusion protein so as produced by the cultured mammalian cell.