Diversity of Epstein–Barr virus BamHI-A rightward transcripts and their expression patterns in lytic and latent infections

Abstract

Epstein-Barr virus (EBV)BamHI-A rightward transcripts (BARTs; also designated complementary strand transcripts or CSTs) have been demonstrated to contain several splicing forms in EBV-infected cells. To date, however, little is known about the actual full-length splicing form and its functions. In the present study, we proved that six forms of BARTs were present in EBV-positive cell lines and various tissue specimens with different EBV infection patterns. Of the BART-encoded genes, mRNA of four major splicing forms, including BARF0, RPMS1, RPMS1A and A73, were expressed in all EBV-infected cells. On the other hand, mRNA of two minor splicing forms, RK-BARF0 and RB3, was rarely detected, or if at all, at very low expression levels. Both RPMS1A and RPMS1 mRNA was transcribed at higher levels in EBV-infected cells. In particular, RPMS1 mRNA was expressed abundantly in epithelial carcinoma cells, including gastric carcinoma and nasopharyngeal carcinoma, in association with a lytic infection signal, BZLF1 mRNA. The four major splicing forms were expressed much less in B-cell lines with an integrated EBV genome than in those with episomal EBV genomes. These data indicate that at least six splicing forms can be expressed by EBV-infected cells or tissues, although the expression patterns or levels differ for different infection states such as lytic and latent infections.

Survival rates and prognostic factors of Epstein-Barr virus-associated hydroa vacciniforme and hypersensitivity to mosquito bites

“…RNA was extracted from the samples with TRIzol ™ reagent (Gibco‐BRL, Gaithersburg, MD, U.S.A.), and the cDNA was amplified by PCR using EBER1‐specific and Bam HI A rightward transcripts (BARTs)‐specific primers, as described previously . The integrity of the RNA was checked by the parallel amplification of beta‐2‐microglobulin (β2‐MG).…”

“…Primer sets for reverse-transcriptase polymerase chain reaction RNA was extracted from the samples with TRIzol TM reagent (Gibco-BRL, Gaithersburg, MD, U.S.A.), and the cDNA was amplified by PCR using EBER1-specific and BamHI A rightward transcripts (BARTs)-specific primers, as described previously. 11,12 The integrity of the RNA was checked by the parallel amplification of beta-2-microglobulin (b2-MG). To detect EBV reactivation, BZLF1 was amplified by RT-PCR, using BZLF1-specific outer primers: sense, 5ʹ-CATGTTTCAACCGC TCCGACTGG-3ʹ, and antisense, 5ʹ-GCGCAGCCTGTCATTTTCA GATG-3ʹ.…”

Genomic assays for Epstein–Barr virus-positive gastric adenocarcinoma

“…Eight of these EBV transcripts ( BARF0 , BALF3 , BALF4 , BALF5 , A73 , RPMS1 , LF2 and LF1 ) are encoded in the Bam H1A region of the viral genome where the expressed viral miRs are also encoded. 10 , 65 , 85 Although the medical literature suggests that latent membrane protein 1 is infrequently expressed in infected gastric adenocarcinoma by protein assays, TCGA RNAseq revealed that both EBV latent membrane protein encoding mRNAs ( LMP1 , LMP2A ) were consistently expressed, albeit at low level. Latent membrane protein 2 or other viral gene products may contribute to hypermethylated DNA that is characteristic of infected cancers.…”

Role of Epstein–Barr Virus in the Pathogenesis of Head and Neck Cancers and Its Potential as an Immunotherapeutic Target

“…However, there is still a lack of supporting evidence for the expression of endogenous BART proteins in EBV-infected cells ( 44 , 79 ). It is also surprising to note that the expression levels of BART are known to vary depending on whether the infection is lytic or latent ( 45 ). These findings demand further detailed investigation to elucidate the potential roles of the BART proteins in the pathogenesis of EBV-induced NPC.…”