IL-2 and IL-18 attenuation of airway hyperresponsiveness requires STAT4, IFN-gamma, and natural killer cells.
IL-18 is known to induce IFN-gamma production, which is enhanced when combined with IL-2. In the present study, we investigated whether the combination of exogenous IL-2 and IL-18 alters airway hyperresponsiveness (AHR) and airway inflammation. Sensitized mice exposed to ovalbumin (OVA) challenge developed AHR, inflammatory cells in the bronchoalveolar lavage (BAL) fluid, and increases in levels of Th2 cytokines and goblet cell numbers. The combination of IL-2 and IL-18, but neither alone, prevented these changes while increasing levels of IL-12 and IFN-gamma. The combination of IL-2 and IL-18 was ineffective in IFN-gamma-deficient and signal transducer and activator of transcription (STAT)4-deficient mice. Flow cytometry analysis showed significant increases in numbers of IFN-gamma-positive natural killer (NK) cells in the lung after treatment with the combination therapy, and transfer of lung NK cells isolated from sensitized and challenged mice treated with the combination significantly suppressed AHR and BAL eosinophilia. These data demonstrate that the combination of IL-2 and IL-18 prevents AHR and airway inflammation, likely through IL-12-mediated induction of IFN-gamma production in NK cells.
Matsubara
Shigeki
S
Division of Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206, USA.
Takeda
Katsuyuki
K
Kodama
Taku
T
Joetham
Anthony
A
Miyahara
Nobuaki
N
Koya
Toshiyuki
T
Swasey
Christina H
CH
Okamoto
Masakazu
M
Dakhama
Azzeddine
A
Gelfand
Erwin W
EW
D019264:Adoptive Transfer; D000818:Animals; D002452:Cell Count; D004357:Drug Synergism; D005260:Female; D020397:Goblet Cells / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007249:Inflammation; D007274:Injections, Intraperitoneal; D007371:Interferon-gamma / Q000172:deficiency / Q000378:metabolism*; D020382:Interleukin-18 / Q000008:administration & dosage / Q000494:pharmacology*; D007376:Interleukin-2 / Q000008:administration & dosage / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000276:immunology* / Q000637:transplantation; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D008679:Metaplasia; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin; D012130:Respiratory Hypersensitivity / Q000628:therapy*; D050797:STAT4 Transcription Factor / Q000172:deficiency / Q000378:metabolism*
D020382:Interleukin-18; D007376:Interleukin-2; D050797:STAT4 Transcription Factor; D007371:Interferon-gamma; D010047:Ovalbumin