Design of cassette baculovirus vectors for the production of therapeutic antibodies in insect cells.
Various systems have been described for the expression of recombinant monoclonal antibodies for therapeutical applications. Insect cells offer great advantages with respect to post-translational modifications, stability, yields and applications. To construct plasmid cassette transfer vectors in order to express chimeric, humanized or human antibodies in insect cells using baculovirus expression system. Two transfer vectors, pBHuC kappa and pBHuC gamma 1, were designed. They contain a viral promoter (polyhedrin or p10 promoters, respectively), a signal peptide sequence and a human immunoglobulin light chain C kappa gene or heavy chain C gamma 1 sequence, respectively. Restriction sites have been introduced to allow insertion of rearranged variable genes, after amplification by polymerase chain reaction. Recombinant baculoviruses expressing complete immunoglobulins have been generated by a double-recombination event between baculovirus DNA and the loaded cassette transfer vectors. Our genetic cassette approach makes this system a very flexible and convenient one for the rapid production of therapeutic monoclonal antibodies with heavy and light chains of any human isotype. Specific variable regions selected by the antibody phage display technology can be easily transferred in these vectors to obtain a complete antibody.