Airway Dysbacteriosis Exacerbated Murine Airway Allergic Inflammation / 中山大学学报(医学科学版)

ABSTRACT

[Objective] To investigate the effects of airway dysbacteriosis on the development of murine atlergic airway diseases (AAD).[Methods] Female C57BL/6 mice were neubulized with Vancomycin for 10 days and then were sacrificed.The bacterial population in bronchoalveolar lavage fluid (BALF) were evaluated using 16S rRNA high-throughput sequencing technology,exploriug the method of establishing an airway dysbacteriosis mouse model.After the mouse model was established successfully,airway dysbacteriosis mouse models were established by the same method,and based on that,the mice were sensitized and challenged with ovalbumin (OVA) to induce airway allergic inflammation.The frequency of nasal rubbing behaviors per mice was counted;the total cell number and eosinophil relative abundance in BALF were evaluated;the lung tissue inflammation and goblet cell metaplasia were assessed according to histopathological features;and the IgE level in serum,IFN-γ,IL-4 and IL-5 levels in BALF,and IL-33 levels in serum,BALF and intestine tissue were measured by ELISA.[Results] Nebulization of Vancomycin increased Bradyrhizobium,Sphingopyxis,Cupriavidus,Pelomonas,and decreased Akkermansia and Prevotella_6 in airway,inducing significant airway dysbacteriosis.Using the animal model,further study found that airway dysbacteriosis exacerbated OVA-induced airway allergic inflammation,including increased nasal rubbing frequency,higher serun IgE level,more total cell count especially eosinophil infiltration,more serious lung tissue inflammation and goblet cell metaplasia.Additionally,compared to OVA group,mice in Dysbacteriosis and OVA group had significantly increased level of Th2 cytokine IL-4 and IL-5,and significantly decreased Thl cytokine IFN-γin BALF,which revealed that mice in Dysbacteriosis and OVA group had mote remarkable Thl/Th2 imbalance.Furthermore,IL-33 level showed a significant increase in BALF,but didn't change in serum or intestine tissue in Dysbacteriosis and OVA group compared to OVA group.Indicating that airway dysbacteriosis may only affect the local production of IL-33.[Conclusions] An airway dysbacteriosis mouse model was established by Vancomycin nebulization successfully.Airway dysbacteriosis may activate innate lymphoid cells (ILC) and Th2 cell by inducing local IL-33 secreting,which leads to the imbalance of Th1/Th2,and in turn promotes the development of AAD.