HEVAg-PLGA纳米颗粒疫苗小鼠体内免疫学研究

Immunogenicity of HEVAg-PLGA Nano-particles in Mice

研究重组戊型肝炎抗原（HEVAg）-乳酸/乙醇酸共聚物（PLGA）纳米颗粒抗原能否在动物体内诱导产生免疫应答。制备HEVAg-PLGA纳米颗粒抗原后,通过皮下、滴鼻、口服途径接种Balb/c小鼠,每隔4周加强免疫两次,HEVAg与铝盐佐剂（铝佐剂疫苗Al2O3-Ag）为对照组,一定时间内检测抗体及细胞因子的应答水平。结果HEVAg-PLGA纳米颗粒抗原在小鼠体内诱导产生有效的体液免疫、细胞免疫。滴鼻、口服途径黏膜系统中诱导产生较高滴度的IgA抗体,ELISPOT结果显示鼻腔、唾液腺中IgA ASCs数量显著增加;皮下途径诱导产生较高滴度的IgG抗体;常规铝佐剂疫苗相比于HEVAg-PLGA纳米颗粒抗原诱导较强的IgG抗体水平,未诱导产生黏膜免疫应答;HEVAg-PLGA纳米颗粒抗原诱导产生较强细胞免疫应答,皮下接种途径IFN-γ、IL-4生成细胞数量显著高于其它免疫组。与铝佐剂疫苗相比,HEVAg-PLGA纳米颗粒抗原能有效诱导产生系统免疫及黏膜免疫应答,显示HEVAg-PLGA有潜力成为备选HEV黏膜疫苗抗原,同时展示PLGA颗粒作为黏膜系统抗原递送载体及黏膜佐剂的优越性。

The aim of this study was to determine whether immunization with HEVAg-PLGA might lead to enhanced immune response including mucosal and system response in mice.HEVAg-PLGA nanoparticles（NPs）,hepatitis E virus ORF2 aa368~606 peptide（HEVAg）-poly-lactide-co-glicolide acid（PLGA）,were prepared and administrated into Balb/c mice in a prime-boost regimen through oral,intranasal and subcutaneous route.The conventional aluminum-adjuvant vaccine（Al2 O3-Ag）was used to immunize mice as control groups.In certain time interval,the immune responses of immunized mice were detected.The HEVAg-PLGA nanoparticles could successfully enhance humoral and cellular immunity in Balb/c mice.Compared with the conventional aluminum adjuvant group,NPs inoculated via oral,intranasal route induced antigen specific IgA Ab in mucosal samples.IgA ASCs increased significantly（P0.05 VS Al2 O3-Ag）in nasal cavity and salivary gland.Both NPs and Al2 O3-Ag induced high titer of antigen specific IgG Ab via subcutaneous route.NPs induced enhanced cellular immunity,IFN-γ、IL-4 producing cells increased significantly in subcutaneous route（P0.05 VS Al2 O3-Ag）.Compared to the Al2 O3-Ag,the HEVAg-PLGA nanoparticles induced effective immune response,especially the mucosal immune response.This study suggests that NPs is a promising mucosal vaccine candidate for HEV,and highlight the effective vaccine carrier and adjuvant properties of PLGA.