Type-A retrovirus particles in heterohybridomas: precaution for human monoclonal antibody purification

Fine structural features of the murine myeloma MHFP-1 and two heterohybridomas secreting human IgM monoclonal antibody were examined. Intracisternal type-A retrovirus particles were found in both MHFP-1 and the heterohydribomas constructed by fusing MHFP-1 and human peripheral blood lymphocytes. The implications of this finding for the purification of human monoclonal antibody for therapeutic applications is discussed.