Human CD8+ T cell responses to EBV EBNA1: HLA class I presentation of the (Gly-Ala)-containing protein requires exogenous processing

Immunity. 1997 Dec;7(6):791-802. doi: 10.1016/s1074-7613(00)80397-0.


Epstein-Barr virus (EBV)-induced cytotoxic T lymphocyte (CTL) responses have been detected against many EBV antigens but not the nuclear antigen EBNA1; this has been attributed to the presence of a glycine-alanine repeat (GAr) domain in the protein. Here we describe the isolation of human CD8+ CTL clones recognizing EBNA1-specific peptides in the context of HLA-B35.01 and HLA-A2.03. Using these clones, we show that full-length EBNA1 is not presented when expressed endogenously in target cells, whereas the GAr-deleted form is presented efficiently. However, when supplied as an exogenous antigen, the full-length protein can be presented on HLA class I molecules by a TAP-independent pathway; this may explain how EBNA1-specific CTLs are primed in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / immunology
  • Antigen Presentation / immunology*
  • Clone Cells
  • Dinucleotide Repeats / immunology
  • Epitopes, T-Lymphocyte / immunology
  • Epstein-Barr Virus Nuclear Antigens / immunology*
  • Glycine / immunology
  • HLA-A Antigens / immunology*
  • Herpesvirus 4, Human / immunology
  • Humans
  • T-Lymphocytes, Cytotoxic / immunology*


  • Epitopes, T-Lymphocyte
  • Epstein-Barr Virus Nuclear Antigens
  • HLA-A Antigens
  • Alanine
  • Glycine