| Abstract: | Inoculation of a cotton-topped marmoset with cell-free EBV, strain B95-8, resulted in the induction of lymphomas in liver, spleen, and mesenteric lymph nodes. Continous suspension cell lines were established from tumor tissue from each of these three sites. Cells of each line were positive for intracellular EBV antigens and EB nuclear antigen and released low levels of transforming virus. Early after initial culturing each line had a high frequency of cells (84-85%) with receptors for activated complement but these receptors were no longer evident on retesting several months later. All three lines initially showed high levels of cells which stained for surface lambda light chain and gamma and mu heavy chains. Cells of all three lines showed a decrease in gamma chain staining and the lymph-node tumor line showed reductions in surface staining for mu and lambda chains as well after prolonged cultivation. Clonal cells of the three lines resembled their respective parental lines in surface markers. Cytogenetically, all the lines were hypodiploid, 2n = 45, and several karyotypes from all three lines showed the loss of a medium-sized metacentric chromosome. A marker chromosome with an extra band in the centromeric region was apparent in the lymph-node tumor line. These results indicate that cells of individual tumors in a cotton-topped marmoset with multiple EBV-induced lymphomas are similar to each other in a number of characteristics although a certain degree of divergence was observed. Thus, it is possible that EBV-induced lymphomas in cotton-topped marmosets may have a common cell origin as is the case with Burkitt lymphoma in humans. |
