Enhanced tumorigenicity of an Epstein-Barr virus-transformed lymphoblastoid cell line is associated with a unique 1:18 chromosomal translocation and decreased expression of lymphocyte function associated antigen-1a (CD11A).

An Epstein-Barr virus-transformed lymphoblastoid cell line was identified that disseminated to multiple organs and grew rapidly when transplanted to severe combined immunodeficient mice. This pattern of growth more closely resembled that of Burkitt's lymphoma cells than that of all other lymphoblastoid cell lines tested. Analysis of the rapidly growing lymphoblastoid cell line showed two distinctive changes. First, all of the cells derived from the tumor had a 1:18 chromosomal translocation [t(1;18)(p32.1;q23.3)]. Second, the lymphoblastoid cell line down-regulated expression of lymphocyte function associated antigen-1a during passage in severe combined immunodeficient mice, but regained expression upon growth in vitro. These two changes seem sufficient to explain the enhanced tumorigenicity of this cell line and may represent examples of changes that lead to more aggressive lymphomas in posttransplant lymphoproliferative disease.