CHARACTERIZATION OF EPSTEIN-BARR-VIRUS RECOMBINANTS WITH DELETIONS OFTHE BAMHI-C-PROMOTER

Epstein-Barr virus (EBV) recombinants with the BamHI C promoter (Cp) d eleted were compared with wild-type Cp recombinants derived in paralle l for their ability to initiate and maintain latent Infection and grow th transformation in primary human B lymphocytes. Cp-deleted recombina nts infected, transformed, and immortalized B lymphocytes in vitro as efficiently as wild-type Cp recombinant EBV. Lymphoblastoid cell lines (LCLs) infected with the Cp-deleted recombinant were indistinguishabl e from wild-type recombinant-infected LCLs in latent gene expression, growth rate, morphology, and surface phenotype. Deletion of Cp did not affect episomal maintenance or spontaneous entry of the virus into ly tic cycle. The effect of steroid hormones on latent and lytic gene exp ression on Cp-deleted recombinants was analyzed and shown to be indepe ndent of the glucocorticoid response element located 5' to Cp. The Bam HI W promoter, Wp, is used to transcribe EBNA genes in Cp-deleted EBV- infected cells. Wp is sufficient for growth transformation and mainten ance of the lymphoblastoid phenotype of EBV-infected lymphocytes in vi tro. (C) 1995 Academic Press, Inc.