EXPRESSION OF CHIMERIC (MOUSE-HUMAN) IMMUNOGLOBULIN GENES IN LYMPHOIDAND NONLYMPHOID CELLS

A tandem of mouse/human immunoglobulin (Ig) genes was constructed and cloned into the pGEM1 plasmid under control of the T7 RNA polymerase p romoter. Constant regions of murine monoclonal antibodies were replace d with human ones. The g isotype was changed from IgG to IgE. The cons truct was transfected into the Sp2/0 lymphoid and Chinese hamster ovar y (CHO) cell lines. Each cell line contained stably expressed a semisy nthetic T7 RNA polymerase gene. Synthesis of Ig mRNA and polypeptides corresponding to light (kappa-, 25 kD) and heavy (epsilon-, 70 kD) cha ins was detected in both transfected cell lines. The antibodies synthe sized in Sp2/0 and CHO cells were functionally active and bound the an tigen (porcine transferrin). Some clones produced up to 150 ng/ml of c himeric antibodies. However, only the lymphoid Sp2/0 but not the nonly mphoid CHO cells were capable of efficient Ig secretion.