Characterization of intertypic recombinants of the Epstein-Barr virus fromthe body-cavity-based lymphomas cell lines BC-1 and BC-2

Epstein-Barr Virus (EBV) can infect and transform human B-lymphocytes and h as been associated with numerous human malignancies. Two distinct types of EBV have been described, EBV-1 and EBV-2. Whereas type 1 is known to be mos t widespread throughout the healthy adult population, type 2 EBV has been s hown to be significantly present in certain T-cell immunocompromised patien ts. Some evidence also suggests that such immune impairment promotes coinfe ction with multiple strains of EBV and fosters the development of intertypi c recombinant viruses. In this work, we have analyzed two established body- cavity-based lymphoma or primary effusion lymphoma cell lines, BC-1 and BC- 2, for the presence of intertypic EBV recombinants. Using PCR primers to am plify across several markers in the genome, we have typed the BC-1 and BC-2 EBV at these loci. Immunoblot analysis of the EBNA1 protein expressed by t hese cell lines also suggests a change in EBV typing at this locus in these genomes. Additionally, we have analyzed the expression patterns of the lat ent EBNA proteins from these viruses and performed Southern blot analysis o f the BamHI- and EcoRI-digested genomes to detect variations occurring from type I and II genomes. On the basis of these data, we suggest that the gen omes of EBV in BC-l and BC-2 are intertypic recombinants of type 1 and type 2 EBV genomes. This work corroborates other reports that intertypic EBV re combinants occur in the immunocompromised population. It is likely that int ertypic recombination is a mechanism by which novel variants of EBV emerge having selective advantages over a strictly type 1 or type 2 strain. (C) 19 99 Academic Press.