Patent ID: 7906327

Claim:
A vector for expression of a heavy chain or light chain of an IgG in mammalian cells and a Fab fragment portion of a heavy chain or light chain in E. coli , said vector comprising: (a) a bacterial origin of replication; (b) a mammalian promoter and/or enhancer sequence; and (c) a nucleotide sequence encoding said heavy chain or said light chain; said nucleotide sequence comprising: (i) a mammalian signal sequence comprising a first intron, said first intron comprising a bacterial promoter and a bacterial signal sequence operatively associated with a sequence encoding the Fab domain of said heavy chain or said light chain, such that said bacterial promoter and bacterial signal sequence direct expression and secretion into the periplasmic space of said Fab domain of said heavy chain or said light chain in a bacterial cell and said mammalian promoter and said mammalian signal sequence directs expression and secretion of said heavy chain or said light chain in a mammalian cell; and (ii) when said vector encodes said heavy chain, a second intron between the CH1 and the hinge region of said heavy chain sequence, said second intron comprising a stop codon, wherein said promoter for expression in mammalian cells is operatively associated with said nucleotide sequence encoding said heavy chain or said light chain.