[Preparation of human monoclonal antibodies reactive with human melanoma and the possibility of clinical application]

Abstract

Human monoclonal antibodies (mAbs) were prepared from the lymph node and peripheral blood lymphocytes (PBL) of the patients with melanoma. NS-1 fusion with lymph node lymphocytes resulted in a higher number of growing hybrids than LICR-LON-HMy2 (LICR-2) fusion. Virtually no hybrids were obtained from NS-1 or LICR-2 fusions with PBL. Epstein-Barr virus transformed the lymphocytes from lymph node and periphered blood with equal efficiency, and the yield of proliferating cultures for antibody screening was more than 10 to 30-fold greater than that obtained by fusion techniques. However, once antibody-producing cultures had been identified, stability and clonability of EBV-transformed cells were poorer than that of NS-1 hybrid cells. To combine the strengths of both methods, cultures of EBV-transformed cells were fused with NS-1, and hybrid clones were isolated that showed vigorous growth, clonability, and stable antibody secretion. Detailed specificity analysis of four mAbs indicated detection of a class 1 (unique) melanoma antigen (GXM1), a class 2 (shared) melanoma antigen (HJM1) and two class 3 (widely distributed) antigen (FCM1 and DSM1). HJM1 reacted most strongly with GD3 and would be a candidate for immunotherapy of melanoma.