FIG 4.

CD8⁺ T cell escape from T/F virus in chronic subject Ch_240. (A) Viral load (shaded gray) and CD8⁺ T cell response measured via ELISpot assay against epitope ₁₆₃₃RLGPVQNEV₁₆₄₁. A moderate immune response was detected against escape variant ₁₆₃₃RLGPVQNEI₁₆₄₁ at 310 days p.i. (no further time points were tested), which reached fixation at 538 days p.i. A detailed list of evolving epitope variants along with the time of detection and frequency of occurrence (%) in the viral population is reported. (B) Viral load (shaded gray) and CD8⁺ T cell response against epitope ₁₆₀₂RAQAPPPSW₁₆₁₀. No immune responses were tested against escape variants. The variant ₁₆₀₂RAQALPPSW₁₆₁₀ rapidly reached fixation at 140 days p.i. A detailed list of evolving epitope variants is reported below. The high-resolution analysis of these epitope regions indicated significant residue toggling across the epitope at low frequency before preferential selection of a variant that coincided with recrudescent viremia. The color coding of the residues in the text correlates with the epitope variant colors in the graphs.