Expression of the Chemokine Receptor BLR2/EBI1 Is Specifically Transactivated by Epstein-Barr Virus Nuclear Antigen 2

In our attempt to identify chemokine receptors that are related to Burkitt′s lymphoma receptor 1 (BLR1) and are expressed in activated lymphocytes we used RT-PCR resulting in the isolation of a cDNA encoding a seven transmembrane receptor termed BLR2. The protein shows significant sequence similarities to the family of G-protein coupled chemokine receptors and turned out to be identical to the recently described receptor EBI1. Northern blot analysis revealed that BLR2 mRNA could be highly stimulated in mitogen- and anti-CD3-treated peripheral blood lymphocytes. BLR2-specific mRNA could be detected in all Epstein-Barr virus positive B cell lines. We show that transcription of the BLR2 gene could be specifically induced in Epstein-Barr virus negative BL 41 cells via estrogen-mediated activation of Epstein-Barr virus nuclear antigen 2, a key regulator of viral and cellular genes in immortalized B cells. Our data suggest an involvement of BLR2 in the regulation of migration in activated lymphocytes and in viral pathogenesis.