T-cell responses to predicted amphipathic peptides of varicella-zoster virus glycoproteins II and IV

Four peptides from the predicted amino acid sequences of varicella-zoster virus (VZV) glycoproteins II and IV selected for potential amphipathicity and a terminal lysine residue were synthesized. The peptides elicited weak proliferative responses by T cells with the CD4+ UCHL1+ CD45R- phenotype from the blood of VZV-immune individuals. The frequency of responder cells in individuals with specific response to peptides was 1:80,000 or fewer blood mononuclear cells, and the number of peptides responded to did not correlate with the proliferative response to VZV antigen. Of 40 peptide-specific T-cell clones obtained by limiting dilution, 10 were restimulated by extracted VZV antigen in the presence of autologous antigen-presenting cells. A total of 50% of these clones lysed HLA class II-positive lymphoblasts which had been preincubated with the appropriate peptide, and 2 of 15 cytotoxic clones lysed lymphoblast targets superinfected with VZV. The data indicated that T cells with specificity for putative VZV peptides may readily be cultured from the subset of blood mononuclear cells which bears the phenotype associated with memory.