Following infection, an increased proportion of activated NK cells in blood expressed Killer Immunoglobulin-like Receptors (KIR).

<p>The proportion of KIR_pos NK cells in blood increased following HIV infection (A). The proportion of KIR_pos NK cells did not differ between stages of primary HIV infection (seronegative, sero-discordant or seropositive stages) (B). KIR_pos NK cells were more activated than KIR_neg NK cells (C).