Antigenic differences between the membrane antigen polypeptides determined by different EB virus isolates

The antigenic specificities of the membrane antigen (MA) complex of three Epstein-Barr (EB) virus-producing cell lines have been compared by complete absorption of an anti-MA antiserum with P3HR-1 cells, followed by testing for residual anti-MA antibody activity against B95-8 and QIMR-WIL cells. Indirect membrane immunofluorescence showed that the absorbed serum, which had lost the capacity to bind P3HR-1 cells, nevertheless gave bright staining on a small proportion of B95-8 cells. SDS-polyacrylamide gel electrophoretic analysis of 125I-labelled MA polypeptides showed that the absorbed serum was able to isolate MA polypeptides from both B95-7 and QIMR-WIL cells, but not from P3HR-2 cells. The results demonstrate that there is substantial sharing of antigenic specificities between the MA determined by three isolates of EB virus, and some antigenic divergence.