犬弓首蛔虫超氧化物歧化酶的免疫保护性分析  

Immuneprotective efficacy of superoxide dismutase of Toxocara canis

作　　者：吴天乐 游怡宁 王磊 王冰楠 孙雪 周荣琼 WU Tianle;YOU Yining;WANG Lei;WANG Bingnan;SUN Xue;ZHOU Rongqiong(College of Veterinary Medicine,Southwest University,Rongchang,Chongqing 402460,China)

机构地区：[1]西南大学动物医学院,重庆荣昌402460

出　　处：《中国兽医学报》2025年第1期66-73,共8页Chinese Journal of Veterinary Science

基　　金：重庆自然科学基金资助项目(cstc2019jcyj-msxmX0140)。

摘　　要：为探究犬弓首蛔虫(Toxocara canis,T.canis)超氧化物歧化酶(superoxide dismutase,SOD)对小鼠的免疫保护效果,选取75只6周龄昆明系小鼠随机分为5组进行免疫保护试验,分别于试验0、14、28 d对每只小鼠皮下注射50、75和125 mg/L的Tc-SOD 0.1 mL,空白组不做任何处理,PBS组注射等量的无菌PBS。共免疫3次,每次免疫间隔14 d;第3次免疫后14 d,经口感染3000个/只感染性虫卵。在每次免疫前、第3次免疫后14 d和攻虫后7 d对小鼠尾静脉采血并分离血清,采用间接ELISA法检测血清中特异性IgG抗体;通过CCK-8和qRT-PCR法分析小鼠脾淋巴细胞的增殖能力及Th1(IFN-γ,IL-2)和Th2(IL-4,IL-10)型细胞因子mRNA的表达水平;计算攻虫后7 d的幼虫减虫率并采用苏木精-伊红(H&E)染色观察肝脏和肺脏的病理变化。结果显示,与PBS组相比,Tc-SOD免疫组小鼠血清IgG抗体水平随着免疫次数的增加和时间延长而升高,攻虫感染后仍维持在较高水平,差异极显著(P<0.001)。三免后14 d,IFN-γ、IL-2、IL-4和IL-10的mRNA表达水平均极显著增高(P<0.01),其中IL-4和IL-10显著高于IFN-γ和IL-2(P<0.05),表现为Th2型为主的免疫反应。小鼠脾淋巴细胞的增殖能力显著增强(P<0.01)。50、75和125 mg/L的Tc-SOD免疫组的幼虫减虫率分别为18.7%、24.9%、37.6%,其中125 mg/L Tc-SOD组差异显著(P<0.05),具有较好的免疫保护效果。H&E染色结果显示,3个Tc-SOD免疫组均缓解了小鼠肝脏和肺脏的炎性细胞浸润(中性粒细胞、嗜酸粒细胞、巨噬细胞)和出血性病变。上述研究结果表明,Tc-SOD可诱导小鼠产生体液免疫和细胞免疫应答,以Th2型免疫反应为主,并对T.canis的感染具有一定程度的免疫保护作用。To investigate the immune protective effect induced by superoxide dismutase(SOD)of the Toxocara canis(T.canis)in mice,in this experiment,seventy-five Kunming mice of six-weekage were randomly divided into 5 groups for the immune protection experiment,the mice were subcutaneously immunized with 50,75 and 125 mg/L Tc-SOD(0.1 mL)on days 0,14 and 28,respectively.In the blank group,mice did not receive any treatment,while the PBS group was injected with equal amounts of sterility PBS.A total of three immunizations and each immunization interval of 14 days.14 days after the third immunization,the 3000 infected worm eggs were given orally in all groups.Pefore each immunization,14 days after the third immunization,and after the T.ranis attack on the 7th day,the blood was sampled from the tail vein and sera were separated,while the IgG levels in serum were detected by indirect ELISA.The proliferation ability of splenic lymphocytes and the mRNA expression levels of Th1(IFN-γ,IL-2)and Th2 cytokines(IL-4,IL-10)were analyzed with CCK-8 and qRT-PCR.The larvae reduction rates were calculated on the 7th day after the T.canis attack,and the pathological changes in the livers and lungs were observed using H&E staining.The results showed that compared with the PBS group,the serum IgG antibody levels increased with the frequency and duration of Tc-SOD immunization.It remained at a high level after the T.canis attack,and the differences were very significant(P<0.001).The mRNA expression levels of TFN-γ,IL-2,IL-4,and IL-10 were dramatically increased(P<0.01),while IL-4 and IL-10 were significantly higher than TFN-γand IL-2 on the 14th day after the third immunization(P<0.05),showing the Th2 type predominant immune response.And induce the proliferation of spleen lymphocytes in vitro(P<0.01).The reduction rates of larvae of 50,78 and 125 mg/L TcSOD immune groups were 18.7%,24.9%and 37.6%,respectively,with significant differences in the 125 mg/L Tc-SOD group(P<0.05),and had better immune protection effect.Moreover,the H&E staining res

关 键 词：小鼠 犬弓首蛔虫 超氧化物歧化酶 免疫应答 

分 类 号：S852.731[农业科学—基础兽医学]