Fig. 6. Host-directed compounds targeting IAV and SARS-CoV-2 host factors identify inhibitors of pH1N1, H3N2 and H5N1 IAV infection.

A Compounds targeting eight IAV PPI factors and 12 IAV-modulated kinases were manually curated by literature search and selected based on target specificity and drug availability. 8 kinase-targeting compounds with antiviral activity against SARS-CoV-2¹⁹ were included. In total, 37 unique compounds were screened against pH1N1, H3N2 and H5N1 IAV infection. Compounds with selectivity index (SI) [CC50/IC50] > 2 were classified as having antiviral activity (Supplementary Data 5, see also Source Data). B–K A549 cells were pre-treated with compound at the indicated doses (2 hr) and infected with pH1N1 (MOI 0.5), H3N2 (MOI 0.5) or H5N1 (MOI 0.05) IAV for 24 hr. Percent IAV-infected cells were quantified by immunostaining for IAV NP followed by high throughput imaging (blue line=pH1N1; green line=H3N2; purple line=H5N1). Percent alive cells were quantified by MTT assay in uninfected A549 cells (black line). Data points represent the mean across n = 3 biologically independent samples. Schematics mark the target with corresponding PPI or PH dataset and IAV strain, and the corresponding compound (at left). Compounds are annotated with IC50 values for IAV strains in which SI > 2. Error bars represent standard error of mean (SEM). B–D Dose-response curves for M2 PPI-targeting compounds, including: ATP6V1A-targeting compound bafilomycin A1; ABCC1-targeting compound daunorubicin; and PRKDC-targeting compound NU7441. PRKDC is also a kinase identified in the IAV PH data. E Dose-response curve for HA PPI P4HB-targeting compound PACMA31. F–G Dose-response curves for PH kinase-targeting compounds, including: CDK2-targeting compound dinaciclib; and ULK1-targeting compound MRT68921. H Dose-response curves for members of the MAPK pathway (pathway schematic at left), including MAP2K3, MAP2K6, MAPK13 and MAPKAPK2, each annotated with corresponding compounds. PF-3644022 was not tested against pH1N1. I–K Dose-response curves for SARS-CoV-2-mined antiviral compounds targeting three kinase pathways: FLT3 and AXL targeted by gilteritinib; PI3KCA and PI3KCD targeted by pictilisib; and AKT1, AKT2 and AKT3 (pan-AKT) targeted by MK-2206. SARS-CoV-2 IC50 values are included as previously reported¹⁹, where SARS-CoV-2 infection was quantified by RT-qPCR of SARS-CoV-2 N protein in compound-treated A549-ACE2 cells.