FIG 4.

Functional-avidity analysis of IE-1 variant-specific T cell populations. Following in vitro expansion for 2 weeks in the presence of cognate peptide and IL-2, IE-1 epitope-specific T cells were incubated for 4 h with 10-fold serial dilutions of both the cognate peptide and the epitope variant. IFN-γ expression was then assessed using an intracellular cytokine assay. The EC₅₀ was calculated based upon the peptide concentration required to induce activation in 50% of the maximal number of IFN-γ-producing cells. (A) Representative peptide titration from YILEETSVML-stimulated T cell cultures from patient 47 recalled with VLEETSVML and YILEETSVML is shown. Data in bottom rows correspond to T cells stimulated ex vivo with VLEETSVML (B), YILEETSVML (C), ELRRKMMYM (D), ELKRKMIYM (E), DELRRKMMY (F), and EEAIVAYTL (G). Color keys at the bottom of each row correspond to the cognate and variant peptides used to recall the T cells response after 2 weeks in culture.