Infiltration of CD3⁻NK1.1⁺ NK cells into the lungs of IL-18/IL-2–treated mice.

B6 mice were treated with control PBS and IL-18 (1 μg) plus IL-2 (50 000 IU) for 4 days; lung lymphocytes were prepared; and FACS analysis was performed as described in “Materials and methods.” Fluorescein isothiocyanate (FITC)–antimouse CD8a mAb, phycoerythrin (PE)–antimouse CD4 mAb, Cy-Chrome–antimouse CD3ε mAb, PE–antimouse NK1.1 mAb, and FITC-, PE-, Cy-–conjugated isotype-matched immunoglobulin were used for FACS analysis.