Figure 2.

GzmK inhibition attenuates LAK cell-mediated clearance of influenza virus. (a) The GzmK inhibitor significantly impedes LAK cell-mediated viral clearance. A549 cells were transfected with influenza A luciferase plasmid pPolI-NS-luc and an intrinsic control plasmid pRL-SV40. After 12 h, treated cells were infected with Flu A/WSN/33 (H1N1) at an MOI of 10⁻² for 2 h. The infected A549 cells were incubated with IL-2-activated LAK cells at an E/T ratio of 1 : 1 followed by luciferase assay. For GzmK inhibition, LAK cells were pretreated with KI for 2 h. ^**P<0.001. (b) GzmK inhibition facilitates LAK cell-mediated replication of the influenza virus. A549 cells were transfected with influenza A polymerase (PB1, PB2, and PA) and NP plasmids (Pol+NP), the luciferase plasmid pPolI-NS-luc, and the control plasmid pRL-SV40, followed by the above assay. ^***P<0.0001