Programmed Death-1 Expression on Epstein Barr Virus Specific CD8+ T Cells Varies by Stage of Infection, Epitope Specificity, and T-Cell Receptor Usage

Abstract

BackgroundProgrammed Death-1 (PD-1) is an inhibitory member of the CD28 family of molecules expressed on CD8+ T cells in response to antigenic stimulation. To better understand the role of PD-1 in antiviral immunity we examined the expression of PD-1 on Epstein-Barr virus (EBV) epitope-specific CD8+ T cells during acute infectious mononucleosis (AIM) and convalescence.Methodology/Principal FindingsUsing flow cytometry, we observed higher frequencies of EBV-specific CD8+ T cells and higher intensity of PD-1 expression on EBV-specific CD8+ T cells during AIM than during convalescence. PD-1 expression during AIM directly correlated with viral load and with the subsequent degree of CD8+ T cell contraction in convalescence. Consistent differences in PD-1 expression were observed between CD8+ T cells with specificity for two different EBV lytic antigen epitopes. Similar differences were observed in the degree to which PD-1 was upregulated on these epitope-specific CD8+ T cells following peptide stimulation in vitro. EBV epitope-specific CD8+ T cell proliferative responses to peptide stimulation were diminished during AIM regardless of PD-1 expression and were unaffected by blocking PD-1 interactions with PD-L1. Significant variability in PD-1 expression was observed on EBV epitope-specific CD8+ T cell subsets defined by V-beta usage.Conclusions/SignificanceThese observations suggest that PD-1 expression is not only dependent on the degree of antigen presentation, but also on undefined characteristics of the responding cell that segregate with epitope specificity and V-beta usage.

HLA-B7–Restricted EBV-Specific CD8+ T Cells Are Dysregulated in Multiple Sclerosis

“…Therefore, we wondered whether such a need for exogenous rhIL-2 reflects an exhaustion of these cells. Yet, ex vivo HLA-B7/EBV RPPspecific CD8 + T cells of MS patients and control subjects are similarly highly differentiated (35); do not express CD57, which is associated with proliferation incompetence and replicative senescence (32); and have low levels of PD-1, a marker of exhaustion that is induced by antigenic stimulation (41). Furthermore, there is greater proliferation of HLA-B7/EBV RPP -specific CD8 + T cells in the MS group after addition of rhIL-2, suggesting that these cells are fully able to respond to IL-2.…”

A Gene Expression Signature That Correlates with CD8+ T Cell Expansion in Acute EBV Infection

“…Fresh whole blood was used to measure the frequencies of EBV-specific CD8+ T cells using Peptide MHC class I (pMHCI) tetramers conjugated to APC and flow cytometry as previously described (21, 22). Antibody specificities and fluorochromes (Becton-Dickinson; San Jose, CA) were as follows: CD14 and CD19 (APC-Cy7), CD3 (PerCP), CD8 (Alexa 405), CD57 (FITC), CD127 (PE), CCR7 (PE-Cy7), CD27 (Alexa 700).…”

Epstein-Barr Virus Latent Membrane Protein 1 Genetic Variability in Peripheral Blood B Cells and Oropharyngeal Fluids

“…The Institutional Review Board of the University of Massachusetts Medical School approved these studies, and all participants provided written informed consent. Blood and oropharyngeal samples were obtained from a previously described cohort of young adults (44,45) who presented with symptoms of AIM, which was further confirmed by a positive monospot (heterophile antibody) assay. Primary EBV infection was confirmed by the detection of serum IgM antibodies at presentation, along with the development of serum IgG antibodies in convalescence, to the EBV viral capsid antigen.…”

“…DNA was extracted using Qiagen (Valencia, CA) DNeasy Mini spin 150 columns. DNA from oral wash samples was isolated using the Roche (Indianapolis, IN) High Pure viral nucleic acid kit, and viral loads were measured using the Roche (Indianapolis, IN) LightCycler EBV quantitation kit by quantitative PCR (qPCR) on the Roche LightCycler system (44,45).…”