CD8A and HIV infectious disease: However, they couldn’t confirm the need for AP-2 in CD8β nor CD4 down-modulation by knock-down of AP-2 α while several previous reports convincingly showed the opposite by knock-down of AP-2 μ2 [14, 25] Although there is some evidence for dysfunctional antiviral CD8 T cell responses in HIV infection (for review see reference [41]), further research has to be done on whether Nef impairs infected CD8+ T cell function.