Patent ID: 7947495

Claim:
An expression vector comprising, in a 5′ to 3′ direction: a promoter; a first exon encoding an immunoglobulin heavy chain variable domain; a second exon encoding an immunoglobulin CH1 domain; a third exon encoding an immunoglobulin hinge domain; a fourth exon encoding an immunoglobulin CH2 domain; a fifth exon encoding a first immunoglobulin heavy chain CH3 domain and a cell surface tether domain; a sixth exon encoding a second immunoglobulin heavy chain CH3 domain, wherein the polynucleotide sequence encoding said second immunoglobulin CH3 domain is identical to the polynucleotide sequence encoding said first immunoglobulin heavy chain CH3 domain; a CH2 splice donor site located adjacent to the 3′ end of said fourth exon encoding the immunoglobulin CH2; a CH3-TM splice acceptor site located adjacent to the 5′ end of said fifth exon encoding the immunoglobulin heavy chain CH3 domain and a cell surface tether domain; a CH3 splice acceptor site located adjacent to the 5′ end of said sixth exon encoding the second immunoglobulin heavy chain CH3 domain; wherein said CH2 splice donor site splices alternatively to: said CH3-TM splice acceptor site to form a first spliced transcript, for producing a membrane-bound immunoglobulin; or said CH3 splice acceptor site to form a second spliced transcript, for producing a secreted immunoglobulin.