CD8 + T cell and NK cell Suppression of HIV-1 Replication. CD8 + T cells (red bars) or NK cells (blue bars) isolated from viremic controllers (VC), elite suppressors (ES), acute progressors (AP) or AC1 (c = control, day 47, v = viremic, day 277, gray box) were co-cultured with autologous CD4 + T cells infected with GFP pseudotyped virus at a 1:1 effector:target ratio (A) or a 1:2 effector:target ratio (B). Suppression was calculated with respect to target only controls.