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Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome
The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vi...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5834210/ https://www.ncbi.nlm.nih.gov/pubmed/29462212 http://dx.doi.org/10.1371/journal.ppat.1006890 |
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author | Szymula, Agnieszka Palermo, Richard D. Bayoumy, Amr Groves, Ian J. Ba abdullah, Mohammed Holder, Beth White, Robert E. |
author_facet | Szymula, Agnieszka Palermo, Richard D. Bayoumy, Amr Groves, Ian J. Ba abdullah, Mohammed Holder, Beth White, Robert E. |
author_sort | Szymula, Agnieszka |
collection | PubMed |
description | The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vitro. We generated EBNA-LP knockout (LPKO) EBVs containing a STOP codon within each repeat unit of internal repeat 1 (IR1). EBNA-LP-mutant EBVs established lymphoblastoid cell lines (LCLs) from adult B cells at reduced efficiency, but not from umbilical cord B cells, which died approximately two weeks after infection. Adult B cells only established EBNA-LP-null LCLs with a memory (CD27+) phenotype. Quantitative PCR analysis of virus gene expression after infection identified both an altered ratio of the EBNA genes, and a dramatic reduction in transcript levels of both EBNA2-regulated virus genes (LMP1 and LMP2) and the EBNA2-independent EBER genes in the first 2 weeks. By 30 days post infection, LPKO transcription was the same as wild-type EBV. In contrast, EBNA2-regulated cellular genes were induced efficiently by LPKO viruses. Chromatin immunoprecipitation revealed that EBNA2 and the host transcription factors EBF1 and RBPJ were delayed in their recruitment to all viral latency promoters tested, whereas these same factors were recruited efficiently to several host genes, which exhibited increased EBNA2 recruitment. We conclude that EBNA-LP does not simply co-operate with EBNA2 in activating gene transcription, but rather facilitates the recruitment of several transcription factors to the viral genome, to enable transcription of virus latency genes. Additionally, our findings suggest that EBNA-LP is essential for the survival of EBV-infected naïve B cells. |
format | Online Article Text |
id | pubmed-5834210 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-58342102018-03-23 Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome Szymula, Agnieszka Palermo, Richard D. Bayoumy, Amr Groves, Ian J. Ba abdullah, Mohammed Holder, Beth White, Robert E. PLoS Pathog Research Article The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vitro. We generated EBNA-LP knockout (LPKO) EBVs containing a STOP codon within each repeat unit of internal repeat 1 (IR1). EBNA-LP-mutant EBVs established lymphoblastoid cell lines (LCLs) from adult B cells at reduced efficiency, but not from umbilical cord B cells, which died approximately two weeks after infection. Adult B cells only established EBNA-LP-null LCLs with a memory (CD27+) phenotype. Quantitative PCR analysis of virus gene expression after infection identified both an altered ratio of the EBNA genes, and a dramatic reduction in transcript levels of both EBNA2-regulated virus genes (LMP1 and LMP2) and the EBNA2-independent EBER genes in the first 2 weeks. By 30 days post infection, LPKO transcription was the same as wild-type EBV. In contrast, EBNA2-regulated cellular genes were induced efficiently by LPKO viruses. Chromatin immunoprecipitation revealed that EBNA2 and the host transcription factors EBF1 and RBPJ were delayed in their recruitment to all viral latency promoters tested, whereas these same factors were recruited efficiently to several host genes, which exhibited increased EBNA2 recruitment. We conclude that EBNA-LP does not simply co-operate with EBNA2 in activating gene transcription, but rather facilitates the recruitment of several transcription factors to the viral genome, to enable transcription of virus latency genes. Additionally, our findings suggest that EBNA-LP is essential for the survival of EBV-infected naïve B cells. Public Library of Science 2018-02-20 /pmc/articles/PMC5834210/ /pubmed/29462212 http://dx.doi.org/10.1371/journal.ppat.1006890 Text en © 2018 Szymula et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Szymula, Agnieszka Palermo, Richard D. Bayoumy, Amr Groves, Ian J. Ba abdullah, Mohammed Holder, Beth White, Robert E. Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title | Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title_full | Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title_fullStr | Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title_full_unstemmed | Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title_short | Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naïve B cells, and facilitates recruitment of transcription factors to the viral genome |
title_sort | epstein-barr virus nuclear antigen ebna-lp is essential for transforming naïve b cells, and facilitates recruitment of transcription factors to the viral genome |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5834210/ https://www.ncbi.nlm.nih.gov/pubmed/29462212 http://dx.doi.org/10.1371/journal.ppat.1006890 |
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