Quantitative analysis of Epstein-Barr virus (EBV)-related gene expression in patients with chronic active EBV infection

Abstract

Chronic active Epstein-Barr virus (CAEBV) infection is a systemic Epstein-Barr virus (EBV)-positive lymphoproliferative disorder characterized by persistent or recurrent infectious mononucleosis-like symptoms in patients with no known immunodeficiency. The detailed pathogenesis of the disease is unknown and no standard treatment regimen has been developed. EBV gene expression was analysed in peripheral blood samples collected from 24 patients with CAEBV infection. The expression levels of six latent and two lytic EBV genes were quantified by real-time RT-PCR. EBV-encoded small RNA 1 and BamHI-A rightward transcripts were abundantly detected in all patients, and latent membrane protein (LMP) 2 was observed in most patients. EBV nuclear antigen (EBNA) 1 and LMP1 were detected less frequently and were expressed at lower levels. EBNA2 and the two lytic genes were not detected in any of the patients. The pattern of latent gene expression was determined to be latency type II. EBNA1 was detected more frequently and at higher levels in the clinically active patients. Quantifying EBV gene expression is useful in clarifying the pathogenesis of CAEBV infection and may provide information regarding a patient's disease prognosis, as well as possible therapeutic interventions.

Characterization and treatment of chronic active Epstein-Barr virus disease: a 28-year experience in the United States

“…Acyclovir acts by inhibiting the viral DNA polymerase, which is expressed during EBV lytic, but not latent gene expression. Although there have been anecdotal reports that acyclovir may have activity in some cases, 7 the observation that EBV-infected cells from patients with CAEBV have a type 2 or 3 latency pattern without lytic gene expression 11,23,27 is consistent with the lack of response to antiviral therapy that we and most others have observed. Similarly, although anecdotal reports suggest that CAEBV may respond to immunomodulatory agents (eg, IFN-␣, 28 IL-2 29 ), we and others have found these agents to be ineffective.…”

Application of flow cytometric in situ hybridization assay to Epstein–Barr virus‐associated T/natural killer cell lymphoproliferative diseases

“…When possible, staining of virus-associated antigens using specific antibodies is the most direct and easiest method of detecting and characterizing EBV-infected cells. Epstein-Barr virus infection of T/NK cells is "latency type II", in which only a few viral antigens (Epstein-Barr virus nuclear antigen-1, latent membrane protein (LMP-1, and LMP-2) are expressed (1,3,33) ; however, there are no antibodies available that can stain their extracellular domains. This, together with their low expression levels and weak antigenicity, makes it difficult to staining EBV-infected cells with antibodies against these antigens.…”

mTOR Inhibitors Induce Cell-Cycle Arrest and Inhibit Tumor Growth in Epstein–Barr Virus–Associated T and Natural Killer Cell Lymphoma Cells

“…Viral mRNA expression was quantified by RT-PCR, as described previously, using b2-microglobulin as an endogenous control and reference gene for relative quantification (28,29). Each experiment was performed in triplicate.…”