Figure 1

HLA-A*0201 binding and immunostimulatory capacity of peptides from BKV LTag sequence. Nonamer peptides identified by standardized assessment of epitope finding algorithms within BKV LTag sequence were tested for MHC affinity by T2 binding assay (panel A). Data are reported as average mean fluorescence intensities from three different experiments. Representative histograms obtained upon incubation of T2 cells in the presence of vaccinia H₃L_184–192 (positive control), pp65_341–350 (irrelevant peptide) and LTag_579–587 (LTag peptide best binder) are also shown. Panel B shows data related to BKV antigen specific serological response to both LTag and VP1 antigen in the group of donors included in the study. Panel C shows responsiveness of PBMCs from BKV LTag seropositive donors cultured in the presence of the indicated peptides. The capacity to induce IFN-γ gene expression upon stimulation ex vivo was analysed by qrt-PCR. Results are depicted as IFN-γ relative gene expression (relative quantification, 2^-ΔΔCt method) as compared to unstimulated PBMCs and include data from all HLA-A*0201+ BKV LTag seropositive donors tested (B to F), including both HLA-A*0201+ BKV LTag seronegative (donor A) and HLA-A*0201 negative (donor G) controls. The results are representative of two independent experiments.