Enhanced expression yield of immunoglobulin a in eukaryotes

A method of producing recombinant secretory immunoglobulin A (sIgA) protein in a eukaryotic expression system, comprising:

• co-transforming a eukaryotic cell with at least four different nucleic acid constructs comprising respective sequences encoding for each component polypeptide of said immunoglobulin, wherein at least one nucleic acid construct comprises a sequence encoding a light chain (LC), at least one nucleic acid construct comprises a sequence encoding a heavy chain (HC), at least one nucleic acid construct comprises a sequence encoding a joining chain (JC), and at least one nucleic acid construct comprises a sequence encoding a secretory component (SC) of said sIgA,
• wherein each nucleic acid construct comprises the same promoter and same signal sequence, such that each of the immunoglobulin component polypeptides will be targeted to the same organelle of the cell for expression and assembly,
• wherein said immunoglobulin component polypeptides are assembled in said eukaryotic cell to yield said recombinant sIgA protein.