FIG 7.

HLA upregulation in response to defective IAV RNAs is dependent on IFN signaling. (A) A549 cells or A549-MAVS-KO cells were infected with FM-MA for 17 h, and relative levels of IFN-β and IFN-λ1 transcripts compared with uninfected controls were analyzed by RT-qPCR (n = 3). (B) A549 cells or A549-MAVS-KO cells were treated with recombinant IFN-β, IFN-λ1, or IFN-λ2, and RNA was harvested over a 12-h time course. The relative expression of HLA-A, -B, and –C transcripts was analyzed by RT-qPCR. (C) The surface expression of HLA-A/B/C was determined by immunostaining and flow cytometry of cells harvested over the time course of IFN treatment described in B (n = 3). (D) Analysis of HLA surface expression on A549 cells transfected with IAV minireplicon expressing defective vRNAs from genome segment 5 or from control pUC19 vector-transfected cells. At 6 h posttransfection, cells were treated with ruxolitinib (Rux) or mock treated. *, P < 0.05; **, P < 0.01; ***, P < 0.001.