Obesity enhances Th2 inflammatory response via natural killer T cells in a murine model of allergic asthma.

Background: Obesity increases the incidence of asthma, but mechanism between asthma and obesity isn't utterly understood. NKT cells are intermediary activist between the innate and adaptive immune. It may play an equally important role in both obesity and asthma. We studied an obese mouse model of allergic asthma to test whether NKT cells act as a linkage in the development of obesity with asthma.

Methods: Balb/c mice were divided into control group (A), asthma model group (B), the obesity group (C) and obesity with asthma group (D), asthma model made by OVA. Obesity was induced. AHR were measured; HE staining of lung was made; NKT cells were detected and IL-4 and IFN-γ concentration were determined.

Results: Lung histology showed airway inflammatory in obesity with asthma are significant than in asthma. IL-4 levels were increased compared with the control group. IFN-γ levels were decreased compared with the control group. More CD69+NKT cells of asthma group and obese asthma group correlated to the enhancement of airway inflammation and AHR. IFN-γ+NKT cells vary in different states not paralleling with CD69+NKT cells.

Conclusion: The activity level of NKT cells in obesity with asthma mice enhances Th2 Inflammatory response by regulating IL-4 and IFN-γ secretion. The activation of NKT enhanced asthma TH2 inflammatory responce. NKT cells play an important role in the development of asthma in obesity.