IL-12-STAT4-IFN-gamma axis is a key downstream pathway in the development of IL-13-mediated asthma phenotypes in a Th2 type asthma model.
IL-4 and IL-13 are closely related cytokines that are produced by Th2 cells. However, IL-4 and IL-13 have different effects on the development of asthma phenotypes. Here, we evaluated downstream molecular mechanisms involved in the development of Th2 type asthma phenotypes. A murine model of Th2 asthma was used that involved intraperitoneal sensitization with an allergen (ovalbumin) plus alum and then challenge with ovalbumin alone. Asthma phenotypes, including airway-hyperresponsiveness (AHR), lung inflammation, and immunologic parameters were evaluated after allergen challenge in mice deficient in candidate genes. The present study showed that methacholine AHR and lung inflammation developed in allergen-challenged IL-4-deficient mice but not in allergen-challenged IL-13-deficient mice. In addition, the production of OVA-specific IgG2a and IFN-gamma-inducible protein (IP)-10 was also impaired in the absence of IL-13, but not of IL-4. Lung-targeted IFN-gamma over-expression in the airways enhanced methacholine AHR and non-eosinophilic inflammation; in addition, these asthma phenotypes were impaired in allergen-challenged IFN-gamma-deficient mice. Moreover, AHR, non-eosinophilic inflammation, and IFN-gamma expression were impaired in allergen-challenged IL-12Rbeta2- and STAT4-deficient mice; however, AHR and non-eosinophilic inflammation were not impaired in allergen-challenged IL-4Ralpha-deficient mice, and these phenomena were accompanied by the enhanced expression of IL-12 and IFN-gamma. The present data suggest that IL-13-mediated asthma phenotypes, such as AHR and non-eosinophilic inflammation, in the Th2 type asthma are dependent on the IL-12-STAT4-IFN-gamma axis, and that these asthma phenotypes are independent of IL-4Ralpha-mediated signaling.
Kim
You-Sun
YS
Department of Life Science, Division of Molecular and Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
Choi
Seng-Jin
SJ
Choi
Jun-Pyo
JP
Jeon
Seong Gyu
SG
Oh
Sun -Young
S-
Lee
Byung-Jae
BJ
Gho
Yong Song
YS
Lee
Chun Geun
CG
Zhu
Zhou
Z
Elias
Jack A
JA
Kim
Yoon-Keun
YK
D000485:Allergens / Q000276:immunology; D000818:Animals; D001249:Asthma / Q000150:complications / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000150:complications / Q000276:immunology / Q000473:pathology; D004195:Disease Models, Animal; D007371:Interferon-gamma / Q000276:immunology*; D018664:Interleukin-12 / Q000276:immunology*; D053712:Interleukin-12 Receptor beta 2 Subunit / Q000378:metabolism; D018793:Interleukin-13 / Q000172:deficiency / Q000276:immunology*; D015847:Interleukin-4 / Q000172:deficiency; D016210:Methacholine Chloride; D051379:Mice; D008822:Mice, Transgenic; D018448:Models, Immunological; D009928:Organ Specificity; D011014:Pneumonia / Q000150:complications / Q000276:immunology / Q000473:pathology; D011956:Receptors, Cell Surface / Q000378:metabolism; D050797:STAT4 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D053662:Interleukin-4 Receptor alpha Subunit
D000485:Allergens; D007371:Interferon-gamma; D018664:Interleukin-12; D053712:Interleukin-12 Receptor beta 2 Subunit; D018793:Interleukin-13; D015847:Interleukin-4; D016210:Methacholine Chloride; D011956:Receptors, Cell Surface; D050797:STAT4 Transcription Factor; C504002:Il4ra protein, mouse; D053662:Interleukin-4 Receptor alpha Subunit