Immune profiles in rural children protecting against asthma

Background: Asthma is common affecting children and early environmental exposure in rural area may affect the subsequent risk of asthma development. The objective of this study is to characterize the immune profiles in asthmatic and non-asthmatic children from urban and rural Southern China. Methods: After an initial screening of 18,000 children from Hong Kong and rural China. The prevalence of asthma in rural China was only one third of that in Hong Kong. We then recruited a case-control sample from Hong Kong (47 controls vs 32 asthmatics) and Conghua, a rural county (47 controls vs 20 asthmatics). Blood samples were collected for regulatory T (Treg) cell count, gene expression and cytokine studies. PBMC were cultured unstimulated, with LPS, or with adaptive stimuli. Results: The adaptive stimuli induced ex vivo cytokine production was higher in Conghua controls and cases compared with that in their Hong Kong counterparts. Significantly higher concentrations of Th1-related cytokines such as IFN-γ, IL-1β and TNF-α were detected in samples from the Conghua group (p Conclusions: Environmental exposures in Conghua potentially regulate cytokine secretion and gene expression of Treg cell and Th17 markers through adaptive stimulation. The very low prevalence of asthma in Conghua children may be partially explained by a propensity to Th1 immunity and increased functional capacity of Treg cells.