Regulation of interleukin-1beta transcription by Epstein-Barr virus involves a number of latent proteins via their interaction with RBP.
Epstein-Barr virus (EBV) infects B cells, resulting in the outgrowth of immortalised lymphoblastoid cell lines (LCLs). Here, we demonstrate through the use of intracellular staining that interleukin-1beta (IL-1beta) is expressed in LCLs and investigate the influence of the individual latent proteins on the expression of IL-1beta. Using RT-PCR, IL-1beta was shown to be up-regulated in EBV-transformed LCLs as well as in group III Burkitt's lymphoma (BL) cell lines, compared with group I BL cell lines. The up-regulation of IL-1beta message could be mediated by the latent membrane protein-1, EBV nuclear proteins 2, 3, 4, and 6 genes. Electrophoretic mobility shift assays (EMSAs) demonstrated that the -300 region of the IL-1beta promoter, which contains a nuclear factor-kappaB (NF-kappaB) binding site, contained a functional RBP binding site. Binding of RBP to this site could be inhibited by addition of EBV nuclear proteins 3 and 6, suggesting that these proteins displace RBP from its recognition sequence, removing transcriptional repression and allowing gene transcription to occur. In group I BL cells, containing low levels of NF-kappaB, only RBP binding was observed in EMSAs, whereas NF-kappaB binding could be demonstrated in EBV-transformed B cell lines containing high levels of activated NF-kappaB. In addition, the expression of latent membrane protein-1 led to activation of NF-kappaB that was capable of binding the IL-1beta promoter. The study demonstrates that EBV can up-regulate IL-1beta expression, possibly by using RBP, NF-kappaB, or both.
Krauer
K G
KG
The Joint Oncology Program, Queensland Institute of Medical Research, University of Queensland, 300 Herston Road, Herston, Brisbane, 4029, Australia.
Belzer
D K
DK
Liaskou
D
D
Buck
M
M
Cross
S
S
Honjo
T
T
Sculley
T
T
D001402:B-Lymphocytes; D001483:Base Sequence; D001665:Binding Sites; D002051:Burkitt Lymphoma; D002461:Cell Line, Transformed; D016384:Consensus Sequence; D005786:Gene Expression Regulation; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D008214:Lymphocytes / Q000276:immunology* / Q000821:virology*; D016328:NF-kappa B / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D007375:Interleukin-1; D016328:NF-kappa B; D009687:Nuclear Proteins; C086925:RBP-2N protein, human; D012097:Repressor Proteins