TCRBV usage in TL9-specific CD8 T-cell populations differs according to the infecting HIV-1 subtype. Each pie chart shows the relative TCRBV usage in TL9-specific CD8 T-cell populations from persons infected with subtype C (A-B) and subtype A (C-D). The color code for the different TRBV gene fragments (ImMunoGeneTics nomenclature) is shown on the right. The top panels (A,C) represent CD8 T-cell populations identified with the autologous subtype-specific tetramer only; the bottom panels (B,D) represent cross-reactive CD8 T-cell populations. N/A indicates not available (population not detected). Full clonotypic sequence information and tetramer binding patterns are shown in supplemental Figure 1.