Production of monoclonal human antibody to HLA-DR5 (DRw11) by mouse/human heterohybridomas.

We describe here the production of a human monoclonal antibody to the HLA-DR5 antigen. A human B-cell line secreting cytotoxic antibody that reacted preferentially with DR5-positive targets was fused to the mouse myeloma P3X63Ag8.653 and the resulting heterohybridomas cloned twice. The clones secreted human IgM (lambda light chain), which showed specificity for the DR5 antigen in cytotoxicity assays and reacted with DRw11-positive but not DRw12-positive targets. These results demonstrate the potential of this approach to the production of human monoclonal antibodies to transplantation antigens.