CD4⁺CD25⁺FOXP3⁺ T cells, Foxp3 gene and protein expression contribute to antiasthmatic effects of San'ao decoction in mice model of asthma

Abstract

Objective: San'ao decoction (SAD) is a commonly used traditional combinatorial formula composed of Herba Ephedrae, Radix Glycyrrhizae and Amygdalus Communis Vas. Early studies showed that in the OVA sensitization asthmatic mice model its compatibility could lower airway reactivity and airway inflammatory cell infiltration. Based on the above results, this study mainly discussed San'ao decoction's immunomodulatory effects on Tregs.

Methods: UPLC-PDA-TOF-MS was applied to analyze chemicals of SAD, and under the optimized chromatographic and MS condition, the major components in SAD were well separated and detected within 22 min. An asthma model was established in BALB/c mice that were sensitized and challenged with ovalbumin. After 2 weeks' treatment, peripheral blood and bronchoalveolar lavage fluid (BALF) were assessed for inflammatory cell counts; histological change of lung tissue were detected; flow cytometry detection of splenic CD4(+)CD25(+)Foxp3(+) Treg cells of the mice were counted; Foxp3 expression in lung tissues were examined as well.

Results: 22 Peaks signal chemical components in SAD were identified by UPLC-QTO-MS method. In terms of the percentage of eosinophile in peripheral blood and bronchoalveolar lavage fluid (BALF), SAD groups were significantly lower (p<0.01) than model group. Compared with model group, lung histological changes of SAD groups were reduced; the proportion of CD4(+)CD25(+)Foxp3(+) Treg cells in CD4(+) cells of asthmatic mice also decreased; SAD significantly increased the proportion of CD4(+)CD25(+)Foxp3(+) Treg cells and promoted Foxp3 expression in a mouse model of asthma.

Conclusion: These results suggest that the antiasthmatic effects of SAD are at least partially associated with CD4(+)CD25(+)Foxp3(+) Treg cells.

Keywords: Asthmatic mice; CD4(+)CD25(+)FOXP3(+) Tregs; Foxp3; San’ao decoction.