Multiple Epstein-Barr Virus Infections in Healthy Individuals (original) (raw)

Epstein-Barr Virus Epidemiology, Serology, and Genetic Variability of LMP-1 Oncogene Among Healthy Population: An Update

Frontiers in oncology, 2018

The Epstein-Barr virus (EBV) is a DNA lymphotropic herpesvirus and the causative agent of infectious mononucleosis. EBV is highly prevalent since it affects more than 90% of individuals worldwide and has been linked to several malignancies including PTLDs, which are one of the most common malignancies following transplantation. Among all the EBV genes, most of the recent investigations focused on studying the LMP-1 oncogene because of its high degree of polymorphism and association with tumorigenic activity. There are two main EBV genotypes, Type 1 and 2, distinguished by the differences in the EBNA-2 gene. Further sub genotyping can be characterized by analyzing the LMP-1 gene variation. The virus primarily transmits through oral secretions and persists as a latent infection in human B-cells. However, it can be transmitted through organ transplantations and blood transfusions. In addition, symptoms of EBV infection are not distinguishable from other viral infections, and therefore,...

Epstein-barr virus (EBV) in healthy carriers: Distribution of genotypes and 30 bp deletion in latent membrane protein-1 (LMP-1) oncogene

Journal of Medical Virology, 2004

There are two types of Epstein Barr virus (EBV): EBV-1 and EBV-2, distinguished by genomic polymorphism in the genes encoding the nuclear antigens (EBNA-2, -3A, -3B, -3C). Latent membrane protein 1 (LMP-1) is an EBV protein with known oncogenic properties. Different variants had been described; among them, a 30 base pair (bp) deletion (del-LMP-1) had been reported in benign and malignant pathologies, but there is little information about its frequency in healthy populations. The aim of this study was to determine the distribution of the EBV genotypes and the 30 bp deletion frequency, in EBV healthy carriers from Argentina. Analysis of EBNA-3C and LMP-1 genes were done by polymerase chain reaction (PCR) followed by Southern blot hybridization on DNA of peripheral blood mononuclear cells (PBMCs) from blood bank donors. EBV-1 was present in 75.9% of samples, EBV-2 in 14.6%, and co-infections with both types in 6.5%. The deleted LMP-1 variant was found in 7.4% of analyzed samples, corresponding 3.2% to deleted variant alone and 4.2% to co-infections with non-deleted form. The non-deleted variant was found in 64.6% whereas in the remaining 28%, no PCR product was detected. These results showed that EBV-1 was the more prevalent type in healthy carriers of Argentina, similar to reports from others countries. A predominance of the nondeleted LMP-1 variant was observed. The presence of co-infections with both types and variants demonstrated that healthy individuals may also harbor multiple EBV infections.

Clinical implications of Epstein-Barr virus strain diversity

Journal of Immunological Sciences, 2018

The Epstein-Barr virus (EBV), a ubiquitous γ-herpesvirus, has been implicated in the etiology of several acute and chronic inflammatory, autoimmune, and malignant diseases. Although considered a genetically stable virus, recent sequence information obtained from a large number of viral isolates from around the world revealed that numerous viral variants exist. Whether these different strains differ in pathogenicity and immunogenicity and thereby contribute to the varying incidence rates of several EBV-associated diseases in different geographical regions is now studied intensively. The recent identification of amino acid sequence polymorphisms in a high percentage of all known virus-specific CD4+ and CD8+ T-cell epitopes, and of holes in the individual T-cell repertoire against epitopes derived from strain variants, may suggest that antiviral immunity is incompletely cross-protective against diverse EBV strains. These findings may have implications for immunological approaches seeking to prevent, monitor, or treat EBV-associated diseases.

Sequence variation of Epstein-Barr virus: viral types, geography, codon usage and diseases

Journal of virology, 2018

138 new Epstein-Barr virus (EBV) genome sequences have been determined. 125 of these and 116 from previous reports were combined to produce a multiple sequence alignment of 241 EBV genomes, which we have used to analyze variation within the viral genome. The type 1/type2 classification of EBV remains the major form of variation and is defined mostly by EBNA2 and EBNA3, but the type 2 SNPs at the EBNA3 locus extend into the adjacent gp350 and gp42 genes, whose products mediate infection of B cells by EBV. A small insertion within the BART miRNA region of the genome was present in 21 EBV strains. EBV from saliva of USA patients with chronic active EBV infection aligned with the wild type EBV genome, with no evidence of WZhet rearrangements. The V3 polymorphism in the Zp promoter for BZLF1 was found to be frequent in nasopharyngeal carcinoma cases both from Hong Kong and Indonesia. Codon usage was found to differ between latent and lytic cycle EBV genes and the main forms of variation ...

Compartmentalization and Transmission of Multiple Epstein-Barr Virus Strains in Asymptomatic Carriers

Journal of Virology, 2003

Infection with the Epstein-Barr virus (EBV) is often subclinical in the presence of a healthy immune response; thus, asymptomatic infection is largely uncharacterized. This study analyzed the nature of EBV infection in 20 asymptomatic immunocompetent hosts over time through the identification of EBV strain variants in the peripheral blood and oral cavity. A heteroduplex tracking assay specific for the EBV gene LMP1 precisely identified the presence of multiple EBV strains in each subject. The strains present in the peripheral blood and oral cavity were often completely discordant, indicating the existence of distinct infections, and the strains present and their relative abundance changed considerably between time points. The possible transmission of strains between the oral cavity and peripheral blood compartments could be tracked within subjects, suggesting that reactivation in the oral cavity and subsequent reinfection of B lymphocytes that reenter the periphery contribute to the...

Epstein-Barr virus in healthy individuals from Portugal

Acta médica portuguesa

The Epstein-Barr virus (EBV) persists for long periods in latent state inside B-lymphocytes after primary infections, and reactivation usually occurs associated to immunosuppression conditions of the host. Recently, the detection of EBV DNA in circulation has been suggested as a predictor marker for the development of EBV related malignancies. The aim of our study was to characterize the frequency of circulating EBV in healthy individuals (n=508) from the North region of Portugal, using peripheral blood samples. Detection was performed by Nested-PCR which amplifies a fragment from the BamHIW region of the EBV genome. Our results revealed an overall frequency of 37.2% positive cases for EBV in circulation, with distinct distribution according to genre (39.7% in male individuals and 33.2% in females). We also found that EBV is more frequent in individuals with more than 56 years old compared to individuals with less than 56 years old (p=0.032; RR=1.41), mainly in the male group (p=0.0...

Epstein-Barr virus genomes are found predominantly in IgA-positive B cells in the blood of healthy carriers

International Journal of Cancer, 1999

B lymphocytes have been identified as the main reservoir of latent Epstein-Barr virus (EBV) in healthy virus carriers. We have established a semi-quantitative PCR method to estimate the EBV genome load in the blood B-cell subpopulation in healthy individuals. EBV DNA was detected in subfractionated IgM-, IgG-and IgA-positive B cells. Between 80% and 90% of the viral DNA was found in the IgA-positive compared with the IgA-negative fraction. Int.

The genetic diversity of Epstein-Barr virus in the setting of transplantation relative to non-transplant settings: A feasibility study

Pediatric transplantation, 2015

This study examines EBV strains from transplant patients and patients with IM by sequencing major EBV genes. We also used NGS to detect EBV DNA within total genomic DNA, and to evaluate its genetic variation. Sanger sequencing of major EBV genes was used to compare SNVs from samples taken from transplant patients vs. patients with IM. We sequenced EBV DNA from a healthy EBV-seropositive individual on a HiSeq 2000 instrument. Data were mapped to the EBV reference genomes (AG876 and B95-8). The number of EBNA2 SNVs was higher than for EBNA1 and the other genes sequenced within comparable reference coordinates. For EBNA2, there was a median of 15 SNV among transplant samples compared with 10 among IM samples (p = 0.036). EBNA1 showed little variation between samples. For NGS, we identified 640 and 892 variants at an unadjusted p value of 5 × 10(-8) for AG876 and B95-8 genomes, respectively. We used complementary sequence strategies to examine EBV genetic diversity and its application t...

Genetic polymorphism of natural Epstein-Barr virus isolates from infectious mononucleosis patients and healthy carriers

Journal of virology, 1988

We analyzed Epstein-Barr virus (EBV) genomes from lymphoblastoid cell lines isolated from patients with infectious mononucleosis and from healthy subjects from California, Hawaii, and Hong Kong between 1970 and 1987. Using genetic polymorphism as epidemiological markers, we found that several genotypes of EBV cocirculate in a community and that although most EBV strains isolated from California and Southern China may be differentiated genotypically, there was no specific association between genotype and disease or time of isolation.