The lungs were aseptically collected from mock- and IAV-infected mice, and single cells were prepared after collagenase digestion of lungs, as previously described (52 (link)). One million cells per sample were stained with Ghost Dye BV510 (Tonbo Biosciences, San Diego, CA) and anti-mouse CD16/CD32 (Fc-blocked) (BD Biosciences, San Jose, CA) at 4°C for 30 min. For cell surface staining, cells were incubated for 30 min at room temperature with anti-mouse CD3–allophycocyanin (APC)–Cyanine 7 (Cy7), CD3–Alexa Fluor 488, CD4–Brilliant Violet 786, CD8–phycoerythrin (PE)–Cy7 (Tonbo Biosciences), CD8-PE-Cy5, CD44-PerP-Cy5.5, CD44-PE-Cy7, CD62L–fluorescein isothiocyanate (FITC), CXCR3-BV650, and CXCR3-PE-Dazzle. For monocytes, cells were stained with Cd11b APC-Cy7, Ly6C-BV711, Ly6G-FITC, and CCR2-PE-Cy7. All the antibodies were purchased from BioLegend unless specified.