Epstein-Barr virus latency in blood mononuclear cells: analysis of viral gene transcription during primary infection and in the carrier state

Abstract

Epstein-Barr virus (EBV) can display different forms of latent infection in B-cell lines in vitro; however, the types of infection normally established by the virus in vivo remain largely unexplored. Here we have approached this question by analyzing the types of viral RNAs present in mononuclear cells freshly isolated from the blood of 14 infectious mononucleosis patients undergoing primary EBV infection and 6 long-term virus carriers. Reverse transcription-PCR amplifications were carried out with a panel of oligonucleotide primers and probes which specifically detect (i) the EBER1 RNA common to all forms of latency, (ii) transcripts either from the Cp and Wp promoters generating all six nuclear antigen (EBNA1,-2,-3A,-3B,-3C,-LP) mRNAs or from the Fp promoter generating a uniquely spliced EBNA1 mRNA, (iii) the latent membrane protein (LMP1 and 2A) mRNAs, and (iv) the BZLF1 mRNA, an immediate-early marker of lytic cycle. Viral transcription in infectious mononucleosis mononuclear cells (and in the B-cell-enriched fraction) regularly included the full spectrum of latent RNAs seen during EBV-induced B-cell growth transformation in vitro, i.e., EBER1, Cp/Wp-initiated EBNA mRNAs, and LMP1/LMP2 mRNAs, in the absence of lytic BZLF1 transcripts. In addition, transcripts with the splice pattern of Fp-initiated EBNA1 mRNA, hitherto seen only in vivo in certain EBV-positive tumors, were frequently detected. In long-term virus carriers, the mononuclear cells were again positive for latent (EBER1) and negative for lytic (BZLF1) markers; Cp/Wp-initiated RNAs were not detected in these samples, but in several individuals it was possible to amplify both Fp-initiated EBNA1 mRNA and LMP2A mRNA signals. We suggest (i) that primary infection is associated with a transient virus-driven

Review of Epstein–Barr virus and post‐transplant lymphoproliferative disorder post‐solid organ transplantation (Review Article)

“…When a balance is reached between ongoing proliferation of EBV-infected B cells and incomplete destruction of infected cells by the secondary EBV-specific memory CTL response, EBV maintains a subclinical infective state throughout the life of the individual. 3,20,21 In SOT recipients, the use of immunosuppression depresses EBVspecific CTL response which may promote the development of uncontrolled EBV-driven B-cell proliferation and tumour formation ( Fig. 1a).…”

Comparison of Humoral Immune Responses to Epstein-Barr Virus and Kaposi’s Sarcoma–Associated Herpesvirus Using a Viral Proteome Microarray

“…In vivo, the reservoir of EBV latent infection is resting memory B cells that have either no EBV protein expression or transient expression of the EBNA1 protein. Expression of the other latency proteins, EBNA2, EBNA3A, EBNA3B, EBNA3C, EBNA-LP, LMP-1, and LMP2A and LMP2B, has been detected in peripheral blood B cells shortly after primary infection and in B cells in tonsillar tissues [10,11]. Lytic replication and expression of the EBV lytic proteins takes place in plasma cells and in epithelial cells [12][13][14].…”

Maintenance and Characterization of an Epstein Barr Virus‐infected CD56‐negative T Cell Lymphoma

“…Each of the cDNAs thus obtained was used as the template for the following PCR. The nucleotide sequences of the forward and reverse primers are cited from the paper of Tierney et al, 22) except for the forward primers of Qp-and Fp-initiated EBNA-1s. The forward primer of Qp-initiated EBNA-1 is from the paper of Chen et al 23) and that of Fp-initiated EBNA-1 is from the paper of Schaefer et al 24) The amplification protocol for Wp promoter, EBNA-1 (Cp/Wp), EBNA-2, and BZLF-1 is as follows: 40 cycles of denaturation at 94°C for 2 min, annealing at 55°C for 1 min, and extension at 72°C for 2 min.…”