Myeloma proteins that bind Hsp65 (GroEL) are polyreactive and are found in high incidence in pristine induced plasmacytomas.

The myeloma proteins produced by 44 plasmacytomas (PCTs) recently induced by pristane in BALB/cAnPt and closely related PCT susceptible congenic strains of mice were isolated chromatographically and screened against a panel of 10 protein, nucleic acid and lipid antigens. This sample was highly unusual because 82% of the proteins had IgG isotopes. Nine of the proteins bound to Hsp65 (GroEL), and all of these were polyreactative. Twenty-one of the myeloma proteins were polyreactive and bound two or more antigens in the panel, and five were monoreactive. Thus, an antigen binding activity was determined for 59% of these myeloma proteins.