Intracellular IFN-γ production by rIL-2–activated NK-cell subsets. (A) Flow cytometric profiles of intracellular amounts of IFN-γ in Siglec-7⁺/CD56⁺ (green), Siglec-7⁻/CD56⁺ (blue), and Siglec-7⁻/CD56⁻ (red) NK-cell subsets from a representative example for a healthy donor (top line), an early (middle line), and a chronic (bottom line) HIV-1–infected patient. (B) The fraction of IFN-γ⁺ NK-cell subsets is presented as a mean of 5 independent experiments (with P values and bars indicating SDs) performed with cells from 5 unrelated healthy donors, 5 unrelated HIV-1 early-infected persons, and LTNPs.