ISOTYPE-DIRECTED ENRICHMENT OF B-CELLS BY MAGNETIC BEADS IN THE GENERATION OF IMMUNOREACTIVE HUMAN MONOCLONAL-ANTIBODIES

Pooled lymphocytes collected from cancer patients were mixed with a bi otinylated murine MAb specific to human IgG(4). To this were added str eptavidin-conjugated magnetic beads, After magnetically separating the bead-lymphocyte complex, the B cells were washed and fused with the W IL-2 derived human fusion partner, SHFP-1, Subsequently derived human- human hybridomas were screened for IgG(4) immunoreactivity to target t umor cell lines, Several hybridomas reacted with a variety of malignan t cell types, including melanoma, neuroblastoma, and pancreatic tumor cells, One hybridoma in particular, designated SC-GM4, recognized an a ntigen by Western blot with an apparent molecular weight of 57 kDa, Th is facile approach of magnetically separating selected populations of lymphocytes should be relatively simple to apply to other antigens and antibodies to preselect the type, class, and properties of the desire d MAb.