Single cell suspensions were stained with combinations of cocktails containing anti-CD3, NK1.1, NKp46, CD11c, CD11b, CD122, and CD132 (eBioscience, San Diego, CA) as indicated for 20 minutes at 4uC. Where indicated, cells were concurrently stained with or without biotinylated anti-IL-15Ra (R&D Systems, Minneapolis, MN) followed by 20 minute incubation with APCconjugated Streptavidin at 4uC. Influenza nuclear protein (NP) MHC class I tetramer [H2-D b /ASNENMETM] were generated by the National Institute of Allergy and Infectious Diseases Tetramer Facility (Emory University, Atlanta, GA). Tetramer staining was conducted at room temperature for 1 hour concurrently with anti-CD3, NK1.1, NKp46, CD8, and CD44 (eBioscience, San Diego, CA). Stained cells were analyzed using a BD LSRII digital flow cytometer (BD Biosciences, San Jose, CA) and either BD FACSDiva or FlowJo software (Tree Star, Inc., Ashland, OR).