Tim-3–expressing CD8⁺ T cells are present in diverse phenotypic profiles. (a) PBMCs from HIV-1–uninfected (n = 3) and chronically HIV-1–infected (n = 3) individuals were labeled with fluorochrome-conjugated mAbs to CD3, CD8, CD4, CD25, and Tim-3. Shown are flow cytometry plots gated on the CD3⁺CD4⁺ population or the CD3⁺CD8⁺ population from two representative individuals. (b) PBMCs from a chronic progressor were labeled with fluorochrome-conjugated mAbs against Tim-3, CD3, CD8, CD28, CD27, CD45RA, CCR7, and CD57, as well as with a dead cell–discriminating marker. Gating was first performed to include only the viable CD3⁺CD8⁺ population in subsequent analyses. Shown are phenotypic representations of the Tim-3^hi population (blue) versus Tim-3^lo population (red). (c) Summary data showing phenotypic profiling for seven chronically HIV-1–infected individuals. Gating for maturation/differentiation markers was determined based on fluorescence minus one controls, and results were analyzed using SPICE software. Shown are the frequencies of populations with the corresponding combination of phenotypic markers, with each individual represented by a single bar.