Binding of HPV tetramer to different CD8⁺ T cells isolated from PBMCs after in vitro stimulation with an HPV peptide. CD8⁺ T cells were isolated from PBMCs after 10 days of in vitro stimulation with autologous HPV-pulsed uninfected B cells (A); HPV-pulsed B cells infected with FP-WT (B); or HPV-pulsed B cells infected with rF-TRICOM (C). 1 × 10⁶ CD8⁺ T cells were stained with PE-labeled HPV MHC-tetramer and subsequently analyzed by FACS. A total of 2 × 10⁵ cells were acquired for each tube.