BKV agnopeptide-specific cellular immune response. IFN-γ responses after stimulation of PBMCs with BKV LT antigen, VP1, and agnoprotein peptides are shown. Results are for HD (n = 10), KT patients without high-level BKV replication (group A; n = 4), KT patients with high-level BKV replication (group B; n = 19), and KT patients after high-level replication (group C; n = 25). Agnoprotein responses were significantly lower than LT antigen and VP1 responses (P < 0.05 by the Kruskal-Wallis test).