Differential gene expression patterns of EBV infected EBNA-3A positive and negative human B lymphocytes.
The genome of Epstein-Barr virus (EBV) encodes 86 proteins, but only a limited set is expressed in EBV-growth transformed B cells, termed lymphoblastoid cell lines (LCLs). These cells proliferate via the concerted action of EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), some of which are rate limiting to establish a stable homeostasis of growth promoting and anti-apoptotic activities. We show here that EBV mutants, which lack the EBNA-3A gene, are impaired but can still initiate cell cycle entry and proliferation of primary human B cells in contrast to an EBNA-2 deficient mutant virus. Surprisingly, and in contrast to previous reports, these viral mutants are attenuated in growth transformation assays but give rise to permanently growing EBNA-3A negative B cell lines which exhibit reduced proliferation rates and elevated levels of apoptosis. Expression profiles of EBNA-3A deficient LCLs are characterized by 129 down-regulated and 167 up-regulated genes, which are significantly enriched for genes involved in apoptotic processes or cell cycle progression like the tumor suppressor gene p16/INK4A, or might contribute to essential steps of the viral life cycle in the infected host. In addition, EBNA-3A cellular target genes remarkably overlap with previously identified targets of EBNA-2. This study comprises the first genome wide expression profiles of EBNA-3A target genes generated within the complex network of viral proteins of the growth transformed B cell and permits a more detailed understanding of EBNA-3A's function and contribution to viral pathogenesis.
Hertle
Marie L
ML
Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.
Popp
Claudia
C
Petermann
Sabine
S
Maier
Sabine
S
Kremmer
Elisabeth
E
Lang
Roland
R
Mages
Jörg
J
Kempkes
Bettina
B
D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000502:physiology* / Q000821:virology*; D002460:Cell Line; D049109:Cell Proliferation; D016000:Cluster Analysis; D019309:Epstein-Barr Virus Nuclear Antigens / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction
C508151:EBNA-3A antigen; D019309:Epstein-Barr Virus Nuclear Antigens