The production of human hybridomas from patients with malignant melanoma. The effect of pre-stimulation of lymphocytes with pokeweed mitogen.

Human immunoglobulin-secreting hybridomas have been produced by fusion of the LICR-LON-HMy2 line with lymph node lymphocytes from patients with malignant melanoma. Immunoglobulin production as measured by reverse haemolytic plaque assay was greater for hybridomas than for the parent HMy2 line. Pre-incubation of unseparated cultures from lymph nodes with pokeweed mitogen resulted in more successful fusions with a greater yield of hybridomas. The hybrids did not, however, have any greater immunoglobulin production than did those from lymphocytes not pre-incubated with pokeweed mitogen. Using lymph node cells from a patient with malignant melanoma of the cervical region, a consistent pattern of increased immunoglobulin binding to three human melanoma cell lines in contrast to a human colonic adenocarcinoma and a human skin-derived fibroblast line was demonstrated.