Human T cell responses to the Epstein-Barr nuclear antigen-1 (EBNA-1) as evaluated by synthetic peptides

Abstract

A panel of synthetic peptides derived from Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) was used to examine human T cell responses to this antigen. In six of seven normal persons with past EBV infection, T cell precursors specific for five peptides (P27, amino acid residues 83–101; P62, 148–166; E31, 353–367; E41, 368–381; and Ell, 461–474) were detectable. The precursor frequencies were in the range of 1:20,000 to <1:100,000 peripheral blood mononuclear cells as determined by limiting dilution analyses. Only two of these peptides were predicted as α-helices; all peptides were glycine-rich. Four other peptides were not reactive in the seven individuals tested. T cell responses were not detectable in donors without prior EBV infection. Infectious mononucleosis patients investigated 4–6 weeks after diagnosis had likewise no detectable peptide-specific T cell precursors. Thus, it appears that T cells recognizing peptides from EBNA-1 arise and persist in people with past EBV infection.