Malignant potential of a cell line isolated from the peripheral blood in infectious mononucleosis

Abstract

A cell line (designated CCRF-RKB) has been isolated in continuous (spinner) suspension culture from the peripheral blood of a patient with infectious mononucleosis. Injection of the cells into neonatal Syrian hamsters resulted in the growth of malignant tumor. In neonatal hamsters treated with antihamster thymus serum (ALS), the tumors were serially transplantable and metastatic. In the first few passages of the tumor grown in ALS-treated neonates, human IgG and IgM were detected in the circulation of the tumor-bearing hamsters. In later passages, 2 tumor sublines developed, one which acquired the capacity to grow without ALS and another which disseminated sufficient numbers of tumor cells into the blood to approach leukemic counts and to enable implanted whole blood to produce tumor. Both tumor sublines killed the host more rapidly than did the parent line. Immunofluorescence methods indicated that the cells of the parent tumor line and both sublines retained human species-specific antigens at the cell surface and lacked hamster antigens.