EPSTEIN-BARR-VIRUS IN B-LYMPHOCYTES - VIRAL GENE-EXPRESSION AND FUNCTION IN LATENCY

Epstein-Barr virus (EBV) is a herpesvirus that infects all human populations. It is carried in “latent” form in peripheral blood B lymphocytes and is shed in the form of virus particles from a site in the oropharynx. This chapter discusses the expression and function of EBV genes during latency. EBV transforms the B lymphocytes of humans and other primates to continuous proliferation in culture, a process called immortalization. The resultant, latently infected lymphoblastoid cell lines (LCLs), support a predominantly latent viral life cycle in which only a few of the 100 or so viral genes are expressed. Viral genes expressed during latency are candidate immortalizing genes. Of all the viral gene products of the latent cycle, function has been demonstrated most clearly for Epstein-Barr nuclear Antigen 1 (EBNAl). The chapter discusses the structure of viral transcripts and promoters for the EBV latent genes and perspective on viral gene expression in the LCL model. The discovery that EBV in BL tumors expresses only EBNAl clearly limits the applicability of the LCL model to other situations. RNA from BL biopsy material and from group I BL cell lines is clearly the focus of study. Information from such studies, particularly the structure of EBNA 1 -expressing transcripts, could aid polymerase chain reaction studies of viral gene expression in peripheral blood B lymphocytes from healthy seropositive individuals. © 1992, Academic Press Inc.