A20免疫治疗过敏性气道炎症小鼠的作用机制研究

Study on the mechanism of A20 immunotherapy for allergic airway inflammation in mice

目的通过应用A20治疗OVA诱导幼年小鼠过敏性气道炎症模型,探究A20对过敏性气道炎症小鼠治疗作用及机制。方法将24只BALB/c幼鼠随机分为正常组、模型组、A20蛋白20μg+2 mg Al(OH)3治疗组、A20蛋白50μg+2 mgAl(OH)3治疗组,每组6只。除正常组小鼠外,其余组小鼠用OVA致敏、滴鼻激发。治疗组用不同剂量A20蛋白腹腔注射治疗。对各组小鼠血清中OVA特异性IgE、IgG2a和IgG1水平,脾细胞培养上清中细胞因子IL-4、TNF-α、IFN-γ、IL-10、TGF-β的含量,小鼠脾细胞中表达IL-10和TGF-β的Treg比例进行检测,对BALF中炎性细胞进行计数、分类,对肺组织病理切片进行观察。结果模型组与正常组相比,特异性IgE、IL-4水平显著增加(P<0.05),肺组织切片中炎症反应较重。治疗组与模型组相比,IgG1、IL-4水平显著降低(P<0.05),IL-10和TGF-β产生显著增加(P<0.05),CD4^(+)IL-10+Treg和CD4^(+)TGF-β+Treg产生显著增加(P<0.05),高剂量A20治疗组增加更加明显(P<0.01)。BALF中嗜酸性粒细胞及中性粒细胞数量降低比较明显(P<0.05)。肺组织切片中炎症反应减轻。结论A20通过促使免疫耐受因子IL-10和TGF-β的产生来抑制Th2反应,从而降低过敏性气道炎症小鼠肺部炎症,而非促进Th1反应。

Objective To explore the therapeutic effect and mechanism of A20 on allergic airway inflammation in young mice induced by OVA.Methods Twenty-four young BALB/C mice were randomly divided into normal group,model group,A20 Protein 20μg+2 mg Al(OH)3 treatment group,and A20 Protein 50μg+2 mg Al(OH)3 treatment group,with 6 mice in each group.Except normal group,other groups were sensitized with OVA and stimulated by nasal drip.Treatment groups were treated with different doses of A20 protein by intraperitoneal injection.The levels of OVA-specific IgE,IgG2a and IgG1 in serum,the contents of cytokines IL-4,TNF-α,IFN-γ,IL-10,and TGF-βin supernatant of spleen cell culture,and the proportion of Treg cells expressing IL-10 and TGF-βin mouse splenocytes were detected,the inflammatory cells in BALF were counted and classified,and the pathological sections of lung tissue were observed.Results The levels of OVA-specific IgE and IL-4 were significantly increased in model group compared to normal group(P<0.05),and the inflammatory reaction in lung tissue sections was severe in model group.Compared to model group,the levels of IgG1 and IL-4 were significantly decreased(P<0.05),the production of IL-10 and TGF-βwas significantly increased(P<0.05),CD4^(+)IL-10+Treg and CD4^(+)TGF-β+Treg were significantly increased(P<0.05)in treatment groups,especially in high dose A20 Group(P<0.01).The count of eosinophil and neutrophil in BALF was also significantly decreased(P<0.05)in treatment groups,with reduced inflammation in the lung biopsy.Conclusions A20 inhibits the Th2 response by stimulating the production of IL-10 and TGF-β,thus reducing the lung inflammation in mice with allergic airway inflammation,rather than promoting the Th1 response.