Murine Influenza Model with IFN-γ Knockout

BALB/c and C57Bl/6 IFN-γ^+/+ and IFN-γ ^−/− mice were originally obtained from Jackson Laboratories (Bar Harbor, ME). 3Rora^+/floxIl7r^Cre mice were generated in the lab of Dr. Andrew N.J. McKenzie (MRC Laboratory of Molecular Biology) ^{24 (link)}. All mice were maintained under specific pathogen-free conditions in the Animal Research Facility at Albany Medical College. Mice were anaesthetized by intraperitoneal (i.p.) injection with 100 μl xylazine (20 mg/ml) and ketamine (1 mg/ml) in PBS. For influenza infections, anaesthetized IFN-γ^+/+ and IFN-γ ^−/− mice were intranasally (i.n.) inoculated with a lethal dose (2000 PFU) H1N1 A/California/04/2009 (CA04). ILC2 deficient animals and their littermate controls (Rora^+/floxIl7r^Cre) were given the median lethal dose (LD₅₀) of 500 PFU. Survival and weight loss were monitored daily for 20 days. The virus was propagated in 10-day-old embryonated chicken eggs (Charles River). The stock titer was measured by standard plaque assay. All experimental procedures were approved by the Institutional Animal Care and Use Committee at Albany Medical College (Protocol Number 11-04004).