CASSETTE BACULOVIRUS VECTORS FOR THE PRODUCTION OF CHIMERIC, HUMANIZED, OR HUMAN-ANTIBODIES IN INSECT CELLS

Plasmid cassette-transfer vectors pBHuC kappa, and pBHuC gamma 1 have been designed which enable the construction of recombinant baculovirus es directing the coexpression of complete immunoglobulin in insect cel ls. We describe the application of these vectors for the expression of a human/mouse chimeric monoclonal antibody of potential immunosuppres sive clinical value derived from a mouse anti-human CD29 monoclonal an tibody (Mu-K20). The chimeric K20 light and heavy chains produced in s f9 insect cells were correctly processed and assembled into a normal i mmunoglobulin which is secreted into the culture medium of infected ce lls. The chimeric mAb Ch-K20-sf9 reproduces in vitro the functional pr operties of the parental mouse K20: including affinity and inhibition of lymphocyte proliferation. These results demonstrate that the baculo virus/insect cell expression system is suitable for the expression of fully active monoclonal antibodies of therapeutic value. Our generic c assette approach makes this system a very flexible and convenient one for the rapid production of either chimeric, humanized or human mAb wi th heavy and light chains of any isotype.