Epstein-Barr virus BHRF1 gene but not the cellular protooncogene bcl-2 is expressed in ataxia-telangiectasia lymphoblastoid lines.

The expression of both the Epstein-Barr virus (EBV) ORF BHRF1 and the cellular protooncogene bcl-2 was studied in EBV-transformed lymphoblastoid B cells from patients with the human genetic disorder ataxia-telangiectasia (A-T). Using the Northern blot technique, it was found that the pattern of transcription of the BHRF1 gene in A-T lymphoblastoids resembled that in EBV-transformed normal lymphoblastoid lines and Burkitt lymphoma (BL) lymphocytes. However, the 1.5-kb mature BHRF1 mRNA species present in normal lymphoblastoid cells and in BL cells was not found in the A-T lymphoblastoid cell lines. Treatment of the A-T lymphoblastoid lines with phorbol ester caused changes in the pattern of the synthesis and quantity of BHRF1-related RNA transcripts. The bcl-2 protooncogene probe did not detect bcl-2-related mRNA in the A-T lymphoblastoid lines.