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Project description:Epstein-Barr virus (EBV) is a human gammaherpesvirus that is causally associated with various lymphomas and carcinomas. Although EBV is not typically associated with multiple myeloma (MM), it can be found in some B-cell lines derived from MM patients. Here, we analyzed two EBV-positive MM-patient-derived cell lines, IM9 and ARH77, and found defective viral genomes and atypical viral gene expression patterns. We performed transcriptome sequencing to characterize the viral and cellular properties of the two EBV-positive cell lines, compared to the canonical MM cell line 8226. Principal-component analyses indicated that IM9 and ARH77 clustered together and distinct from 8226. Immunological Genome Project analysis designated these cells as stem cell and bone marrow derived. IM9 and ARH77 displayed atypical viral gene expression, including leaky lytic cycle gene expression with an absence of lytic DNA amplification. Genome sequencing revealed that the EBV genomes in ARH77 contain large deletions, while IM9 has copy number losses in multiple EBV loci. Both IM9 and ARH77 showed EBV genome heterogeneity, suggesting cells harboring multiple and variant viral genomes. We identified atypical high-level expression of lytic genes BLRF1 and BLRF2. We demonstrated that short hairpin RNA (shRNA) depletion of BLRF2 altered viral and host gene expression, including a reduction in lytic gene activation and DNA amplification. These findings demonstrate that aberrant viral genomes and lytic gene expression persist in rare B cells derived from MM tumors, and they suggest that EBV may contribute to the etiology of MM. IMPORTANCE EBV is an oncogenic herpesvirus, but its mechanisms of oncogenesis are not fully understood. A role for EBV in MM has not yet been established. We analyzed EBV-positive B-cell lines derived from MM patients and found that the cells harbored defective viral genomes with aberrant viral gene expression patterns and cell gene signatures for bone marrow-derived lymphoid stem cells. These findings suggest that aberrant EBV latent infection may contribute to the etiology of MM.
| S-EPMC8315968 | biostudies-literature
Project description:Epstein-Barr virus (EBV) is a human gamma-herpesvirus that is causally associated with various lymphomas and carcinomas. Although EBV is not typically associated with multiple myeloma (MM), it can be found in some B-cell lines derived from multiple myeloma patients. Here, we analyzed two EBV+ MM-patient derived cell lines IM9 and ARH77 and found defective viral genomes and atypical viral gene expression patterns. We performed RNA-seq transcriptomics to characterize the viral and cellular properties of the two EBV+ cell lines compared to canonical MM cell line 8226. Principal component analyses indicated that IM9 and ARH77 clustered together and distinct from 8226. ImmGen analysis designate these cells as stem-cell and bone marrow derived. IM9 and ARH77 displayed atypical viral gene expression, including a leaky lytic cycle gene expression with absence of lytic DNA amplification. Genome sequencing revealed that EBV genomes in ARH77 contain large deletions, while IM9 has copy number losses in multiple EBV loci. Both IM9 and ARH77 have numerous EBV genome heterogeneity suggestive of cell harboring multiple and variant viral genomes. Among the lytic genes, we identified atypical high-level expression of BLRF2 and BLRF1. BRLF2 encodes a tegument protein previously shown to bind BNRF1 and to also interact with cGAS, similar to KSHV ORF52, also known as the inhibitor of cGAS (KicGAS). We demonstrate the shRNA depletion of BLRF2 alters viral and host gene expression, including a reduction in lytic gene activation and DNA amplification. These findings demonstrate that aberrant viral genomes and lytic gene expression persist in rare B-cells derived from MM tumors, and suggest that EBV may contribute to etiology of MM.
2021-04-07 | GSE171494 | GEO
Project description:Epstein-Barr virus (EBV) is a human gamma-herpesvirus that is causally associated with various lymphomas and carcinomas. Although EBV is not typically associated with multiple myeloma (MM), it can be found in some B-cell lines derived from multiple myeloma patients. Here, we analyzed two EBV+ MM-patient derived cell lines IM9 and ARH77 and found defective viral genomes and atypical viral gene expression patterns. We performed RNA-seq transcriptomics to characterize the viral and cellular properties of the two EBV+ cell lines compared to canonical MM cell line 8226. Principal component analyses indicated that IM9 and ARH77 clustered together and distinct from 8226. ImmGen analysis designate these cells as stem-cell and bone marrow derived. IM9 and ARH77 displayed atypical viral gene expression, including a leaky lytic cycle gene expression with absence of lytic DNA amplification. Genome sequencing revealed that EBV genomes in ARH77 contain large deletions, while IM9 has copy number losses in multiple EBV loci. Both IM9 and ARH77 have numerous EBV genome heterogeneity suggestive of cell harboring multiple and variant viral genomes. Among the lytic genes, we identified atypical high-level expression of BLRF2 and BLRF1. BRLF2 encodes a tegument protein previously shown to bind BNRF1 and to also interact with cGAS, similar to KSHV ORF52, also known as the inhibitor of cGAS (KicGAS). We demonstrate the shRNA depletion of BLRF2 alters viral and host gene expression, including a reduction in lytic gene activation and DNA amplification. These findings demonstrate that aberrant viral genomes and lytic gene expression persist in rare B-cells derived from MM tumors, and suggest that EBV may contribute to etiology of MM.
2021-04-07 | GSE165195 | GEO
Project description:Epstein-Barr virus (EBV) is a human gamma-herpesvirus that is causally associated with various lymphomas and carcinomas. Although EBV is not typically associated with multiple myeloma (MM), it can be found in some B-cell lines derived from multiple myeloma patients. Here, we analyzed two EBV+ MM-patient derived cell lines IM9 and ARH77 and found defective viral genomes and atypical viral gene expression patterns. We performed RNA-seq transcriptomics to characterize the viral and cellular properties of the two EBV+ cell lines compared to canonical MM cell line 8226. Principal component analyses indicated that IM9 and ARH77 clustered together and distinct from 8226. ImmGen analysis designate these cells as stem-cell and bone marrow derived. IM9 and ARH77 displayed atypical viral gene expression, including a leaky lytic cycle gene expression with absence of lytic DNA amplification. Genome sequencing revealed that EBV genomes in ARH77 contain large deletions, while IM9 has copy number losses in multiple EBV loci. Both IM9 and ARH77 have numerous EBV genome heterogeneity suggestive of cell harboring multiple and variant viral genomes. Among the lytic genes, we identified atypical high-level expression of BLRF2 and BLRF1. BRLF2 encodes a tegument protein previously shown to bind BNRF1 and to also interact with cGAS, similar to KSHV ORF52, also known as the inhibitor of cGAS (KicGAS). We demonstrate the shRNA depletion of BLRF2 alters viral and host gene expression, including a reduction in lytic gene activation and DNA amplification. These findings demonstrate that aberrant viral genomes and lytic gene expression persist in rare B-cells derived from MM tumors, and suggest that EBV may contribute to etiology of MM.
2021-04-07 | GSE165194 | GEO
Project description:Defective Epstein-Barr Virus Genomes and Atypical Viral Gene Expression in B-Cell Lines Derived from Multiple Myeloma Patients
| PRJNA693528 | ENA
Project description:Defective Epstein-Barr Virus Genomes and Atypical Viral Gene Expression in B-Cell Lines Derived from Multiple Myeloma Patients [III]
| PRJNA719811 | ENA
Project description:Defective Epstein-Barr Virus Genomes and Atypical Viral Gene Expression in B-Cell Lines Derived from Multiple Myeloma Patients [II]
| PRJNA693531 | ENA
Project description:Defective Epstein-Barr Virus Genomes and Atypical Viral Gene Expression in B-Cell Lines Derived from Multiple Myeloma Patients [I]
| PRJNA693530 | ENA
Project description:Mounting evidence indicates that infection with Epstein-Barr virus (EBV) has a major role in the pathogenesis of multiple sclerosis (MS). Defective elimination of EBV-infected B cells by CD8+ T cells might cause MS by allowing EBV-infected autoreactive B cells to accumulate in the brain. Here we undertake a comprehensive analysis of the T-cell response to EBV in MS, using flow cytometry and intracellular IFN-γ staining to measure T-cell responses to EBV-infected autologous lymphoblastoid cell lines and pools of human leukocyte antigen (HLA)-class-I-restricted peptides from EBV lytic or latent proteins and cytomegalovirus (CMV), in 95 patients and 56 EBV-seropositive healthy subjects. In 20 HLA-A2+ healthy subjects and 20 HLA-A2+ patients we also analysed CD8+ T cells specific for individual peptides, measured by binding to HLA-peptide complexes and production of IFN-γ, TNF-α and IL-2. We found a decreased CD8+ T-cell response to EBV lytic, but not CMV lytic, antigens at the onset of MS and at all subsequent disease stages. CD8+ T cells directed against EBV latent antigens were increased but had reduced cytokine polyfunctionality indicating T-cell exhaustion. During attacks the EBV-specific CD4+ and CD8+ T-cell populations expanded, with increased functionality of latent-specific CD8+ T cells. With increasing disease duration, EBV-specific CD4+ and CD8+ T cells progressively declined, consistent with T-cell exhaustion. The anti-EBNA1 IgG titre correlated inversely with the EBV-specific CD8+ T-cell frequency. We postulate that defective CD8+ T-cell control of EBV reactivation leads to an expanded population of latently infected cells, including autoreactive B cells.
| S-EPMC5292561 | biostudies-literature
Project description:Virus-like particles (VLPs) from hepatitis B and human papillomaviruses have been successfully used as preventative vaccines against these infectious agents. These VLPs consist of a self-associating capsid polymer formed from a single structure protein and are devoid of viral DNA. Since virions from herpesviruses consist of a large number of molecules of viral and cellular origin, generating VLPs from a subset of these would be a particularly arduous task. Therefore, we have adopted an alternative strategy that consists of producing DNA-free defective virus particles in a cell line infected by a herpesvirus mutant incapable of packaging DNA. We previously reported that an Epstein-Barr virus (EBV) mutant devoid of the terminal repeats (?TR) that act as packaging signals in herpesviruses produces substantial amounts of VLPs and of light particles (LPs). However, ?TR virions retained some infectious genomes, and although these mutants had lost their transforming abilities, this poses potential concerns for clinical applications. Therefore, we have constructed a series of mutants that lack proteins involved in maturation and assessed their ability to produce viral DNA-free VLP/LPs. Some of the introduced mutations were deleterious for capsid maturation and virus production. However, deletion of BFLF1/BFRF1A or of BBRF1 resulted in the production of DNA-free VLPs/LPs. The ?BFLF1/BFRF1A viruses elicited a potent CD4(+) T-cell response that was indistinguishable from the one obtained with wild-type controls. In summary, the defective particles produced by the ?BFLF1/BFRF1A mutant fulfill the criteria of efficacy and safety expected from a preventative vaccine.
| S-EPMC3571473 | biostudies-literature