Type I IFN promotes NK cell expansion during viral infection by protecting NK cells against fratricide

Madera, Sharline; Rapp, Moritz; Firth, Matthew A.; Beilke, Joshua N.; Lanier, Lewis L.; Sun, Joseph C.

Flow cytometry and cell sorting. The blocking of Fc receptors was performed with 2.4G2 mAb before staining with the indicated surface or intracellular antibodies (BD, BioLegend, and eBioscience). Flow cytometry was performed using an LSR II flow cytometer (BD). NKG2D ligand staining was done using mouse NKG2D-human Ig fusion protein for 30 min at 4°C, followed by PE-conjugated goat anti-human IgG Fc antibody (Luminex) for 15 min at 4°C. In proliferation assays, NK cells were labeled with 5-µM CTV (Invitrogen) before transfer, and labeling was performed according to the manufacturer's protocol (Invitrogen). The data were analyzed using FlowJo software (Tree Star). The enrichment and adoptive transfer of NK cells were performed as previously described (Sun et al., 2012) .