旋毛虫肌幼虫期胞外囊泡对小鼠免疫保护作用

本试验通过差速超速离心法获得旋毛虫肌幼虫期胞外囊泡(Trichinella spiralis muscle larvae extracellular vesicles,Ts-ML-EVs),经透射电镜观察、纳米颗粒追踪分析、流式细胞术和Western blot鉴定.选择6～8周龄的健康雌性BALB/c小鼠,随机分为4组...

Immune protection effects of Trichinella spiralis muscle larvae extracellular vesicles on mice

In this study, the Trichinella spiralis muscle larvae extracellular vesicles(Ts-ML-EVs) were obtained by ultracentrifugation.Bilayer vesicles were identified by observation under transmission electron microscopy, nanoparticle tracking analysis, flow cytometry analysis and Western blot.Thirty-two aged 6 to 8 weeks healthy mice were chose and divided into 4 groups: PBS control group(PBS group),adjuvant control group(PBS + adjuvant group),Trichinella spiralis muscle larvae excretory secretory immunize group(Ts-ML-ES + adjuvant group) and Trichinella spiralis muscle larvae extracellular vesicles group(Ts-ML-EVs + adjuvant group).Mice were vaccinated subcutaneously with mixed antigen + adjuvant two and four weeks after first vaccination.The immunization was strengthened once at two and four weeks after the first immunization, and the dose remained unchanged.Two weeks after the third immunization, each mouse was gavaged with 300 Trichinella spiralis muscle larvae, 6 d later, 2 mice from each group were chose to count adult worm burden, then thirty-five days after infection, all the mice were euthanasia, then larvae burden was count.Before each immunization,infection with muscle larvae and euthanasia,the serum was collected to carry out the next experiment.The results showed that Ts-ML-EVs were obtained successfully,the specific IgG,IgG1,IgG2 a,IgA and IgE antibody levels in serum were significantly increased with the increase of immunization times,and reached the highest level two weeks after the third immunization,while the IgM antibody level reached the highest level two weeks after the second immunization,and the antibody level began to decline after the third immunization.The levels of Th1(IFN-γ,IL-12)and Th2(IL-4,IL-10)cytokines were also significantly increased,and reached the highest level two weeks after the third immunization,and the changes of Th2 type were more obvious,suggesting that Ts-ML-EVs could induce humoral immunity and cell-mediated immunity response mainly based on Th2 type immune response in mice.Reduction of adult worms and muscle larvae burden rate of Ts-ML-EVs was 23.4% and 43.7%,respectively,indicating that that Ts-ML-EVs had a great immune protection effect on mice,these results lay a foundation for the development of a new and highly effective vaccine against trichinosis.