Expression of the protein encoded by Epstein-Barr virus (EBV) BARF1 open reading frame from a recombinant adenovirus system

Epstein-Barr virus (EBV) has been associated with human cancers of lymphocytic or epithelial origin, but viral functions implied in oncogenesis are not yet clear. We previously reported the oncogenic transformation of rodent fibroblast and human B lymphocyte cell lines by the BARF1 coding sequence from EBV. We more recently observed immortalizing effects of this gene on monkey kidney primary epithelial cells. Here we describe an efficient recombinant adenovirus expression system which allowed us to characterize BARF1 translation products, with the help of rabbit polyclonal antibodies raised to the entire protein. The present data demonstrate that BARF1 encodes a 31–33 kDa hydrophobic protein, linked to cell membranes though also recovered in the cytosol, and recognized by human sera from patients with various EBV-related pathologies.