Observations of IgG1 anti-DNP hybridoma-mediated ADCC and the failure of three IgM anti-DNP hybridomas to mediate ADCC.

Contaminating heterophile antibodies capable of mediating ADCC to SRBC and CRBC were found in the sera of IgM hybridoma-bearing mice. The activity was directed against erythrocyte membrane determinants, and not TNP determinants, and could be completely removed by absorption with erythrocytes. This heterophile antibody-mediated ADCC could be inhibited by both IgG2a-and IgM-aggregated myeloma protein.