Abstract: The aim of this study was to investigate the effect of UBC13 protein on the polarization of Th2 and Th17 cells in asthma model mice.18 BALB/c mice were randomly divided into PBS,asthma model (OVA) and UBC13 protein (UBC13) groups.The OVA and UBC13 groups were sensitized and aerosolized using ovalbumin (OVA) and lipopolysaccharide (LPS) to establish asthma model.Then 0.5 h before each atomization,UBC13 group was intraperitoneally injected with 100 μg UBC13.After 24 h of the last atomization,all mice were killed and samples were taken.HE and PAS staining were used to observe the pathological changes of lung sections and the secretion of airway mucus,respectively.The IgE concentration in serum and the levels of IL-4,IL-5 and IL-17A in bronchoalveolar lavage fluid (BALF) were detected by ELISA,the relative expression of Th2 (IL-4,IL-5,IL-13 and IFN-γ) and Th17 (IL-1β,IL-6,IL-17A and IL-23) cytokines were detected by Real-time PCR.The results showed that the asthma model was successfully established.Compared with PBS group,the IgE content in OVA group increased extremely significantly (P < 0.01),and the lung also occured the pathological changes.The relative expression of IL-1β,IL-4,IL-6,IL-13 and IL-17A mRNA increased extremely significantly in lung (P < 0.01),the relative expression of IL-5 and IL-23 mRNA increased significantly (P < 0.05),the relative expression of IFN-γ mRNA declined extremely significantly (P < 0.01),and the levels of IL-4,IL-5 and IL-17A in BALF increased extremely significantly (P < 0.01).In addition,compared with OVA group,the serum IgE content declined significantly in UBC13 group (P < 0.05).HE and PAS stainings results showed that inflammatory cell infiltration and mucus secretion decreased in pathological sections.The relative expression of IL-1β,IL-4,IL-17A,IL-13 and IL-23 mRNA declined significantly in lung (P < 0.05),the relative expression of IFN-γ mRNA increased significantly in lung (P<0.05),the relative expression of IL-6 mRNA declined significantly (P < 0.01).The level of IL-4 and IL-5 in BALF decreased significantly (P < 0.01;P < 0.05),but the level of IL-17A was not significant difference (P > 0.05).It indicated that UBC13 protein could downregulate the expression of Th2 and Th17 cytokines and inhibit the polarization of Th2 and Th17 cells in asthma model.

Key words: UBC13; asthma; Th2 cell; Th17 cell