Early T Cell Recognition of B Cells following Epstein-Barr Virus Infection: Identifying Potential Targets for Prophylactic Vaccination

PLoS Pathog. 2016 Apr 20;12(4):e1005549. doi: 10.1371/journal.ppat.1005549. eCollection 2016 Apr.

Abstract

Epstein-Barr virus, a B-lymphotropic herpesvirus, is the cause of infectious mononucleosis, has strong aetiologic links with several malignancies and has been implicated in certain autoimmune diseases. Efforts to develop a prophylactic vaccine to prevent or reduce EBV-associated disease have, to date, focused on the induction of neutralising antibody responses. However, such vaccines might be further improved by inducing T cell responses capable of recognising and killing recently-infected B cells. In that context, EBNA2, EBNA-LP and BHRF1 are the first viral antigens expressed during the initial stage of B cell growth transformation, yet have been poorly characterised as CD8+ T cell targets. Here we describe CD8+ T cell responses against each of these three "first wave" proteins, identifying target epitopes and HLA restricting alleles. While EBNA-LP and BHRF1 each contained one strong CD8 epitope, epitopes within EBNA2 induced immunodominant responses through several less common HLA class I alleles (e.g. B*3801 and B*5501), as well as subdominant responses through common class I alleles (e.g. B7 and C*0304). Importantly, such EBNA2-specific CD8+ T cells recognised B cells within the first day post-infection, prior to CD8+ T cells against well-characterised latent target antigens such as EBNA3B or LMP2, and effectively inhibited outgrowth of EBV-transformed B cell lines. We infer that "first wave" antigens of the growth-transforming infection, especially EBNA2, constitute potential CD8+ T cell immunogens for inclusion in prophylactic EBV vaccine design.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Viral / immunology*
  • B-Lymphocytes / virology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Enzyme-Linked Immunospot Assay
  • Epitopes, T-Lymphocyte / immunology
  • Epstein-Barr Virus Infections / immunology*
  • Humans
  • Immunoblotting
  • Lymphocyte Activation / immunology*
  • Viral Vaccines / immunology

Substances

  • Antigens, Viral
  • Epitopes, T-Lymphocyte
  • Viral Vaccines