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Alves PD, Rohan P, Hassan R, Abdelhay E. Lytic and Latent Genetic Diversity of the Epstein-Barr Virus Reveals Raji-Related Variants from Southeastern Brazil Associated with Recombination Markers. Int J Mol Sci 2024; 25:5002. [PMID: 38732219 PMCID: PMC11084898 DOI: 10.3390/ijms25095002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/27/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous gammaherpesvirus etiologically associated with benign and malignant diseases. Since the pathogenic mechanisms of EBV are not fully understood, understanding EBV genetic diversity is an ongoing goal. Therefore, the present work describes the genetic diversity of the lytic gene BZLF1 in a sampling of 70 EBV-positive cases from southeastern Brazil. Additionally, together with the genetic regions previously characterized, the aim of the present study was to determine the impact of viral genetic factors that may influence EBV genetic diversity. Accordingly, the phylogenetic analysis of the BZLF1 indicated two main clades with high support, BZ-A and BZ-B (PP > 0.85). Thus, the BZ-A clade was the most diverse clade associated with the main polymorphisms investigated, including the haplotype Type 1 + V3 (p < 0.001). Furthermore, the multigene phylogenetic analysis (MLA) between BZLF1 and the oncogene LMP1 showed specific clusters, revealing haplotypic segregation that previous single-gene phylogenies from both genes failed to demonstrate. Surprisingly, the LMP1 Raji-related variant clusters were shown to be more diverse, associated with BZ-A/B and the Type 2/1 + V3 haplotypes. Finally, due to the high haplotypic diversity of the Raji-related variants, the number of DNA recombination-inducing motifs (DRIMs) was evaluated within the different clusters defined by the MLA. Similarly, the haplotype BZ-A + Raji was shown to harbor a greater number of DRIMs (p < 0.001). These results call attention to the high haplotype diversity of EBV in southeast Brazil and strengthen the hypothesis of the recombinant potential of South American Raji-related variants via the LMP1 oncogene.
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Affiliation(s)
- Paula D. Alves
- Oncovirology Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
- Stem Cell Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
| | - Paulo Rohan
- Oncovirology Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
- Stem Cell Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
| | - Rocio Hassan
- Oncovirology Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
| | - Eliana Abdelhay
- Stem Cell Laboratory, Division of Specialized Laboratories, Instituto Nacional de Câncer (INCA), Rio de Janeiro 20230-130, RJ, Brazil
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Palmer WH, Telford M, Navarro A, Santpere G, Norman PJ. Human herpesvirus diversity is altered in HLA class I binding peptides. Proc Natl Acad Sci U S A 2022; 119:e2123248119. [PMID: 35486690 PMCID: PMC9170163 DOI: 10.1073/pnas.2123248119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/30/2022] [Indexed: 11/18/2022] Open
Abstract
Herpesviruses are ubiquitous, genetically diverse DNA viruses, with long-term presence in humans associated with infrequent but significant pathology. Human leukocyte antigen (HLA) class I presents intracellularly derived peptide fragments from infected tissue cells to CD8+ T and natural killer cells, thereby directing antiviral immunity. Allotypes of highly polymorphic HLA class I are distinguished by their peptide binding repertoires. Because this HLA class I variation is a major determinant of herpesvirus disease, we examined if sequence diversity of virus proteins reflects evasion of HLA presentation. Using population genomic data from Epstein–Barr virus (EBV), human cytomegalovirus (HCMV), and Varicella–Zoster virus, we tested whether diversity differed between the regions of herpesvirus proteins that can be recognized, or not, by HLA class I. Herpesviruses exhibit lytic and latent infection stages, with the latter better enabling immune evasion. Whereas HLA binding peptides of lytic proteins are conserved, we found that EBV and HCMV proteins expressed during latency have increased peptide sequence diversity. Similarly, latent, but not lytic, herpesvirus proteins have greater population structure in HLA binding than nonbinding peptides. Finally, we found patterns consistent with EBV adaption to the local HLA environment, with less efficient recognition of EBV isolates by high-frequency HLA class I allotypes. Here, the frequency of CD8+ T cell epitopes inversely correlated with the frequency of HLA class I recognition. Previous analyses have shown that pathogen-mediated natural selection maintains exceptional polymorphism in HLA residues that determine peptide recognition. Here, we show that HLA class I peptide recognition impacts diversity of globally widespread pathogens.
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Affiliation(s)
- William H. Palmer
- Division of Biomedical Informatics and Personalized Medicine, University of Colorado, Aurora, CO 80045
- Department of Immunology and Microbiology, University of Colorado, Aurora, CO 80045
| | - Marco Telford
- Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
| | - Arcadi Navarro
- Institut de Biologia Evolutiva (Universitat Pompeu Fabra - Consejo Superior de Investigaciones Científicas), Department of Medicine and Life Sciences (MELIS), Barcelona Biomedical Research Park, Universitat Pompeu Fabra, 08003 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats and Universitat Pompeu Fabra, 08010 Barcelona, Spain
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, 08003 Barcelona, Spain
- Barcelona Beta Brain Research Center, Pasqual Maragall Foundation, 08005 Barcelona, Spain
| | - Gabriel Santpere
- Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
| | - Paul J. Norman
- Division of Biomedical Informatics and Personalized Medicine, University of Colorado, Aurora, CO 80045
- Department of Immunology and Microbiology, University of Colorado, Aurora, CO 80045
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Telford M, Hughes DA, Juan D, Stoneking M, Navarro A, Santpere G. Expanding the Geographic Characterisation of Epstein-Barr Virus Variation through Gene-Based Approaches. Microorganisms 2020; 8:E1686. [PMID: 33138327 PMCID: PMC7692309 DOI: 10.3390/microorganisms8111686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022] Open
Abstract
The Epstein-Barr Virus (EBV) infects the vast majority of human individuals worldwide (~90%) and is associated with several diseases, including different types of cancer and multiple sclerosis, which show wide variation in incidence among global geographical regions. Genetic variants in EBV genomic sequences have been used to determine the geographical structure of EBV isolates, but our understanding of EBV diversity remains highly incomplete. We generated sequences for 13 pivotal EBV genes derived from 103 healthy individuals, expanding current EBV diversity datasets with respect to both geographic coverage and number of isolates per region. These newly generated sequences were integrated with the more than 250 published EBV genomes, generating the most geographically comprehensive data set of EBV strains to date. We report remarkable variation in single-gene phylogenies that, when analysed together, show robust signals of population structure. Our results not only confirm known major global patterns of geographic variation, such as the clear separation of Asian isolates from the rest, and the intermixed relationships among African, European and Australian isolates, but yield novel phylogenetic relationships with previously unreported populations. We provide a better understanding of EBV's population structure in South America, Africa and, by the inclusion of Turkey and Georgia, we also gain insight into EBV diversity in Western Asia, a crossroads connecting Europe, Africa and Asia. In summary, our results provide a detailed world-wide characterisation of EBV genetic clusters, their enrichment in specific geographic regions, novel inter-population relationships, and a catalogue of geographically informative EBV genetic variants.
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Affiliation(s)
- Marco Telford
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Department of Experimental and Health Sciences (DCEXS), Barcelona Biomedical Research Park, 08003 Barcelona, Spain; (M.T.); (D.J.)
| | - David A. Hughes
- Bristol Population Health Science Institute, University of Bristol, Bristol BS8 2BN, UK;
| | - David Juan
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Department of Experimental and Health Sciences (DCEXS), Barcelona Biomedical Research Park, 08003 Barcelona, Spain; (M.T.); (D.J.)
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany;
| | - Arcadi Navarro
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Department of Experimental and Health Sciences (DCEXS), Barcelona Biomedical Research Park, 08003 Barcelona, Spain; (M.T.); (D.J.)
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain
- Catalan Institution of Research and Advanced Sciences (ICREA), 08010 Barcelona, Spain
- Barcelonaβeta Brain Research Center and Pasqual Maragall Foundation, Carrer Wellington 30, 08005 Barcelona, Spain
| | - Gabriel Santpere
- Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), Department of Experimental and Health Sciences (DCEXS), Universitat Pompeu Fabra, 08003 Barcelona, Spain
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Natural Variations in BRLF1 Promoter Contribute to the Elevated Reactivation Level of Epstein-Barr Virus in Endemic Areas of Nasopharyngeal Carcinoma. EBioMedicine 2018; 37:101-109. [PMID: 30420297 PMCID: PMC6286269 DOI: 10.1016/j.ebiom.2018.10.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 12/12/2022] Open
Abstract
Background Epstein-Barr virus (EBV) infection is a crucial risk factor for nasopharyngeal carcinoma (NPC), but the mechanism for its elevated activation level in NPC endemic areas remains unclear. This study aims to identify the EBV natural variations contributed to the different reactivation potential between NPC endemic and non-endemic areas. Methods 1030 subjects were recruited in China, including 303 healthy individuals from two NPC non-endemic areas, 483 healthy people from three endemic areas and 244 NPC patients. Among which, saliva DNA samples from 244 participants were sequenced for the EBV immediate early (IE) genes of BRLF1 and BZLF1, their promoters were included; the rest 786 subjects were used for the validation of significant variations among three different populations. Haplotype and population structure analysis were conducted. Dual-luciferase assay was used to detect the promoter activity. Results A total of 246 distinct variations were detected, 29 showed significant difference in the frequencies between healthy people from NPC endemic area and non-endemic area. Population structure analysis clustered EBV strains into 9 subgroups mostly in accordance with the geographical origin of samples. Interestingly, two EBV genotypes, Rp-V1 and Rp-V2, were identified according to the linkage relationship of the variations in BRLF1 promoter (Rp). Rp-V1 has higher frequency in NPC endemic areas than in non-endemic areas (52.38% vs 18.15%, P = 2.07 × 10−14), and was associated with higher oral EBV DNA levels (adjusted OR = 1.64, 95% CI = 1.21–2.24, P = .002), suggesting a more powerful activation ability of Rp-V1 than that of the prototype Rp-of the EBV strain; On the contrary, Rp-V2 has higher frequency in NPC non-endemic areas than in endemic areas (18.48% vs 0.38%, P = 1.17 × 10−7), might represent a reduced activation potential of EBV. Further dual-luciferase assay showed Rp-V1 has higher promoter activity while compared with Rp-V2 (P < .0001). Notably, Rp-V1 impaired the transcription repression effect of YY1 while Rp-V2 strengthened the transcription repression effect of EBF1 on Rp. In addition, significant differences of Rta 393–407 CTL epitope which may influence the recognition of Rta by CD8+ T cells were detected between healthy people from NPC endemic area and non-endemic area. Conclusions This study identified natural variations in cis-acting elements (YY1 and EBF1) of EBV Rp altering Rp transcription activities, which may contribute to the elevated EBV activation level in NPC endemic areas than non-endemic areas.
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Abstract
What is wild-type Epstein-Barr virus and are there genetic differences in EBV strains that contribute to some of the EBV-associated diseases? Recent progress in DNA sequencing has resulted in many new Epstein-Barr virus (EBV) genome sequences becoming available. EBV isolates worldwide can be grouped into type 1 and type 2, a classification based on the EBNA2 gene sequence. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than type 2 EBV and molecular mechanisms that may account for this difference in cell transformation are now becoming understood. Study of geographic variation of EBV strains independent of the type 1/type 2 classification and systematic investigation of the relationship between viral strains, infection and disease are now becoming possible. So we should consider more directly whether viral sequence variation might play a role in the incidence of some EBV-associated diseases.
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Affiliation(s)
- Paul J Farrell
- Section of Virology, Department of Medicine, Imperial College, St Mary's Campus, Norfolk Place, London, W2 1PG, UK.
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Lorenzetti MA, Gantuz M, Altcheh J, De Matteo E, Chabay PA, Preciado MV. Epstein-Barr virus BZLF1 gene polymorphisms: malignancy related or geographically distributed variants? Clin Microbiol Infect 2014; 20:O861-9. [PMID: 24666405 DOI: 10.1111/1469-0691.12631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 03/21/2014] [Accepted: 03/21/2014] [Indexed: 11/29/2022]
Abstract
The ubiquitous Epstein-Barr virus (EBV) is related to the development of several lymphoid and epithelial malignancies and is also the aetiological agent for infectious mononucleosis (IM). BZLF1, an immediate early gene, plays a key role in modulating the switch from latency to lytic replication, hence enabling viral propagation. Polymorphic variations in the coded protein have been studied in other geographical regions in a search for viral factors that are inherent to malignancies and differ from those present in benign infections. In the present study, in samples of paediatric patients with benign IM and paediatric patients with malignant lymphomas, we detected previously described sequence variations as well as distinctive sequence polymorphisms from our region. By means of phylogenetic reconstruction, we characterized new phylogenetically distinct variants. Moreover, we described an association between specific variants and the studied pathologies in our region, particularly variant BZLF1-A2 with lymphomas and BZLF1-C with IM. Additionally, length polymorphisms within intron 1 were also assessed and compared between pathologies resulting in an association between 29-bp repeated units and lymphomas. In conclusion, this is the first report to characterize BZLF1 gene polymorphisms in paediatric patients from our geographical region and to suggest the association of these polymorphisms with malignant lymphomas.
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Affiliation(s)
- M A Lorenzetti
- Molecular Biology Laboratory, Pathology Division, Ricardo Gutiérrez Children Hospital, Buenos Aires, Argentina
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Yang Y, Jia Y, Wang Y, Wang X, Sun Z, Luo B. Sequence analysis of EBV immediate-early gene BZLF1 and BRLF1 in lymphomas. J Med Virol 2014; 86:1788-95. [PMID: 24615673 DOI: 10.1002/jmv.23911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2014] [Indexed: 12/20/2022]
Abstract
The immediate-early (IE) genes, BZLF1 and BRLF1, play an important role in switching Epstein-Barr virus from the latent to the lytic state. The functions of the two IE genes and their respective proteins: ZEBRA and Rta have been well studied, but little is known about their DNA coding sequence variations and disease association. In order to investigate the sequence variation patterns and elucidate their association with lymphomas, BZLF1 and BRLF1 were analyzed in 26 and 33 lymphomas using PCR-direct sequencing method respectively. Three sequence variation types of BZLF1 gene were identified. The type BZLF1-A and BZLF1-B was detected in 34.6% (9/26) and 57.7% (15/26) of the tumor specimens, respectively. Among the three functional domains of ZEBRA, the transactivation domain had the most mutations. Three variation types were also identified in BRLF1 gene where type BR1-A and BR1-C were detected in 27.3% (9/33) and 69.7% (23/33) of specimens, respectively. Among the three functional domains of Rta, the dimerization domain was well conserved while multiple mutations were detected in both the DNA binding domain and the transactivation domain. The variation types BZLF1-B and BR1-C were more frequent in the lymphomas, compared with the throat washing samples from the healthy donors. These results suggest that the type BZLF1-B and BR1-C may be associated with the tumorigenesis of lymphoma.
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Affiliation(s)
- Ying Yang
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, 266021, China
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Epstein-barr virus sequence variation-biology and disease. Pathogens 2012; 1:156-74. [PMID: 25436768 PMCID: PMC4235690 DOI: 10.3390/pathogens1020156] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 10/16/2012] [Accepted: 10/30/2012] [Indexed: 12/12/2022] Open
Abstract
Some key questions in Epstein-Barr virus (EBV) biology center on whether naturally occurring sequence differences in the virus affect infection or EBV associated diseases. Understanding the pattern of EBV sequence variation is also important for possible development of EBV vaccines. At present EBV isolates worldwide can be grouped into Type 1 and Type 2, a classification based on the EBNA2 gene sequence. Type 1 EBV is the most prevalent worldwide but Type 2 is common in parts of Africa. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than Type 2 EBV. Molecular mechanisms that may account for this difference in cell transformation are now becoming clearer. Advances in sequencing technology will greatly increase the amount of whole EBV genome data for EBV isolated from different parts of the world. Study of regional variation of EBV strains independent of the Type 1/Type 2 classification and systematic investigation of the relationship between viral strains, infection and disease will become possible. The recent discovery that specific mutation of the EBV EBNA3B gene may be linked to development of diffuse large B cell lymphoma illustrates the importance that mutations in the virus genome may have in infection and human disease.
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Luo B, Tang X, Jia Y, Wang Y, Chao Y, Zhao C. Sequence variation of Epstein-Barr virus (EBV) BZLF1 gene in EBV-associated gastric carcinomas and nasopharyngeal carcinomas in Northern China. Microbes Infect 2011; 13:776-82. [DOI: 10.1016/j.micinf.2011.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 03/19/2011] [Accepted: 04/06/2011] [Indexed: 12/23/2022]
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Jia Y, Wang Y, Chao Y, Jing Y, Sun Z, Luo B. Sequence analysis of the Epstein-Barr virus (EBV) BRLF1 gene in nasopharyngeal and gastric carcinomas. Virol J 2010; 7:341. [PMID: 21106109 PMCID: PMC3002924 DOI: 10.1186/1743-422x-7-341] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/25/2010] [Indexed: 12/15/2022] Open
Abstract
Background Epstein-Barr virus (EBV) has a biphasic infection cycle consisting of a latent and a lytic replicative phase. The product of immediate-early gene BRLF1, Rta, is able to disrupt the latency phase in epithelial cells and certain B-cell lines. The protein Rta is a frequent target of the EBV-induced cytotoxic T cell response. In spite of our good understanding of this protein, little is known for the gene polymorphism of BRLF1. Results BRLF1 gene was successfully amplified in 34 EBV-associated gastric carcinomas (EBVaGCs), 57 nasopharyngeal carcinomas (NPCs) and 28 throat washings (TWs) samples from healthy donors followed by PCR-direct sequencing. Fourteen loci were found to be affected by amino acid changes, 17 loci by silent nucleotide changes. According to the phylogenetic tree, 5 distinct subtypes of BRLF1 were identified, and 2 subtypes BR1-A and BR1-C were detected in 42.9% (51/119), 42.0% (50/119) of samples, respectively. The distribution of these 2 subtypes among 3 types of specimens was significantly different. The subtype BR1-A preferentially existed in healthy donors, while BR1-C was seen more in biopsies of NPC. A silent mutation A/G was detected in all the isolates. Among 3 functional domains, the dimerization domain of Rta showed a stably conserved sequence, while DNA binding and transactivation domains were detected to have multiple mutations. Three of 16 CTL epitopes, NAA, QKE and ERP, were affected by amino acid changes. Epitope ERP was relatively conserved; epitopes NAA and QKE harbored more mutations. Conclusions This first detailed investigation of sequence variations in BRLF1 gene has identified 5 distinct subtypes. Two subtypes BR1-A and BR1-C are the dominant genotypes of BRLF1. The subtype BR1-C is more frequent in NPCs, while BR1-A preferentially presents in healthy donors. BR1-C may be associated with the tumorigenesis of NPC.
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Affiliation(s)
- Yuping Jia
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, PR China
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Functional interaction between Epstein-Barr virus replication protein Zta and host DNA damage response protein 53BP1. J Virol 2009; 83:11116-22. [PMID: 19656881 DOI: 10.1128/jvi.00512-09] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr virus (EBV; human herpesvirus 4) poses major clinical problems worldwide. Following primary infection, EBV enters a form of long-lived latency in B lymphocytes, expressing few viral genes, and it persists for the lifetime of the host with sporadic bursts of viral replication. The switch between latency and replication is governed by the action of a multifunctional viral protein Zta (also called BZLF1, ZEBRA, and Z). Using a global proteomic approach, we identified a host DNA damage repair protein that specifically interacts with Zta: 53BP1. 53BP1 is intimately connected with the ATM signal transduction pathway, which is activated during EBV replication. The interaction of 53BP1 with Zta requires the C-terminal ends of both proteins. A series of Zta mutants that show a wild-type ability to perform basic functions of Zta, such as dimer formation, interaction with DNA, and the transactivation of viral genes, were shown to have lost the ability to induce the viral lytic cycle. Each of these mutants also is compromised in the C-terminal region for interaction with 53BP1. In addition, the knockdown of 53BP1 expression reduced viral replication, suggesting that the association between Zta and 53BP1 is involved in the viral replication cycle.
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Chang CM, Yu KJ, Mbulaiteye SM, Hildesheim A, Bhatia K. The extent of genetic diversity of Epstein-Barr virus and its geographic and disease patterns: a need for reappraisal. Virus Res 2009; 143:209-21. [PMID: 19596032 DOI: 10.1016/j.virusres.2009.07.005] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 06/30/2009] [Accepted: 07/02/2009] [Indexed: 12/12/2022]
Abstract
Epstein-Barr virus (EBV) is a ubiquitous, gamma-1 lymphotrophic virus etiologically linked to nasopharyngeal carcinoma (NPC), endemic to Southern China, and Burkitt lymphoma (BL), endemic to equatorial Africa, both of which are rare elsewhere in the world. Why EBV is associated with different malignancies in different geographic regions remains puzzling and may be related to EBV genotypic variability through specific disease and geographic associations. We review the literature on sequence variation in EBV genes, focusing on LMP-1, EBNA-1, and BZLF-1 and their distribution by geography and disease. Given the limitations of current studies, definitive conclusions regarding the link between EBV genotypes, disease and geography are not possible. We suggest that the true extent of EBV diversity is likely to be greater than is currently recognized. Additional studies conducted in carefully selected populations, that are sufficiently powered to provide robust estimates, and that utilize testing approaches that permit full characterization of viral diversity are needed to further our understanding of patterns of EBV genetic variation and their association with malignancies in different regions.
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Affiliation(s)
- Cindy M Chang
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Blvd., EPS 7074, Rockville, MD 20892, USA.
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