Direct and indirect regulation of cytokine and cell cycle proteins by EBNA-2 during Epstein-Barr virus infection.
We have studied the pathways of regulation of cytokine and cell cycle control proteins during infection of human B lymphocytes by Epstein-Barr virus (EBV). Among 30 cytokine RNAs analyzed by the RNase protection assay, tumor necrosis factor alpha (TNF-alpha), granulocyte colony-stimulating factor, lymphotoxin (LT), and LTbeta were found to be regulated within 20 h of EBV infection of primary B cells. Similar results were obtained using the estrogen-regulated EBNA-2 cell line EREB2.5, in which RNAs for LT and TNF-alpha were induced within 6 h of activation of EBNA-2. Expression of Notch also caused an induction of TNF-alpha RNA. The induction of TNF-alpha RNA by EBNA-2 was indirect, and constitutive expression of either LMP-1 or c-myc proteins did not substitute for EBNA-2 in induction of TNF-alpha RNA. Cyclin D2 is also an indirect target of EBNA-2-mediated transactivation. EBNA-2 was found to activate the cyclin D2 promoter in a transient-transfection assay. A mutant of EBNA-2 that does not bind RBP-Jkappa retained some activity in this assay, and activation did not depend on the presence of B-cell-specific factors. Deletion analysis of the cyclin D2 promoter revealed that removal of sequences containing E-box c-myc consensus DNA binding sequences did not reduce EBNA-2-mediated activation of the cyclin D2 promoter in the transient-transfection assay. The results indicate that cytokines are an early target of EBNA-2 and that EBNA-2 can regulate cyclin D2 transcription in EBV-infected cells by mechanisms additional to the c-myc pathway.
Ludwig Institute for Cancer Research, Imperial College School of Medicine, London W2 1PG, United Kingdom.
L C
LC
Spender
G H
GH
Cornish
B
B
Rowland
B
B
Kempkes
P J
PJ
Farrell
D048868:Adaptor Proteins, Signal Transducing; D000841:Anisomycin / Q000494:pharmacology; D001402:B-Lymphocytes / Q000378:metabolism* / Q000821:virology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics*; D002478:Cells, Cultured; D056742:Cyclin D2; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016213:Cyclins / Q000235:genetics / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D016207:Cytokines / Q000235:genetics*; D003598:Cytoskeletal Proteins; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000235:genetics; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008233:Lymphotoxin-alpha / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D023282:Nuclease Protection Assays; D011401:Promoter Regions, Genetic / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051880:Receptors, Notch; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D025521:Tumor Suppressor Proteins; D014764:Viral Proteins
D048868:Adaptor Proteins, Signal Transducing; C080336:CCND2 protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D056742:Cyclin D2; D016213:Cyclins; D016207:Cytokines; D003598:Cytoskeletal Proteins; C402641:EBNA-2 protein, Human herpesvirus 4; D019309:Epstein-Barr Virus Nuclear Antigens; D004967:Estrogens; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008233:Lymphotoxin-alpha; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C484380:PDLIM7 protein, human; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D051880:Receptors, Notch; D014409:Tumor Necrosis Factor-alpha; D025521:Tumor Suppressor Proteins; D014764:Viral Proteins; D016179:Granulocyte Colony-Stimulating Factor; D050760:Cyclin-Dependent Kinase Inhibitor p27; D000841:Anisomycin; D003513:Cycloheximide