Class I HLA upregulation in IAV-infected cells is MAVS dependent. A549 cells or A549-MAVS-KO cells were infected with FM-MA at an MOI of 1. RNA was harvested for RT-qPCR at 3 hpi or 17 hpi. (A) Relative fold change in HLA-A, -B, and -C transcript levels in A549 cells or A549-MAVS-KO cells at 17 hpi (n = 3). (B) Relative fold change in B2M, TAP, and PSMB8 transcript levels in A549 and A549 MAVS-KO cells at 3 hpi or 17 hpi (n = 3). (C) Relative MFI of cell surface HLA proteins in FM-MA-infected A549 cells and A549-MAVS-KO cells at indicated times, relative to uninfected controls. *, P < 0.05; **, P < 0.01; ***, P < 0.001.