A comparison of Epstein-Barr virus specific proteins expressed by three Epstein-Barr virus isolates using specific monoclonal antibodies.

Monoclonal antibodies (MAbs) were prepared in mice inoculated with a nasopharyngeal carcinoma Epstein-Barr virus (NPC-EBV) producer lymphoblastoid cell line (NPC-LC). When the 214A9 MAb was used to study the expression of the 52/50-kD early antigen in NPC-LC, B95-8, and HR-1 cells, no difference was found. The same results were obtained with the 343D12 MAb which is to a 125-kD virus capsid antigen protein. However, the 244G11 MAb detected an EBV membrane antigen (MA) with a molecular weight of 220 kD in both B95-8 and HR-1 cells, but reacted with a 250-kD MA protein in the NPC-LC cells. Similar results were obtained with the 201D6 MAb which reacted with a MA polypeptide with a molecular weight of 220/200 kD in HR-1 and B95-8 cells and one of 250/200 kD in NPC-LC cells. The data suggest that there may be differences in at least two MA proteins synthesized by the NPC-EBV isolate as compared with the prototype HR-1 and B95-8 EBV isolates.