The E protein of dengue virus type Ⅱ was presented on ferritin of Helicobacter pylori to construct a novel dengue nanoparticle vaccine candidate,and the immunological indexes of the vac-cine were evaluated,aiming to provide new ideas for the development of dengue vaccine.The re-combinant plasmid of E-Ferritin was optimized and synthesized,and then transfected into HEK-293F cells.The recombinant protein was expressed,identified,purified and analyzed.Mice were im-munized with E-Ferritin nanoparticle vaccine by intramuscular injection on the hind limbs on the day 0,14 and 28.ELISA,neutralization test,flow cytometry and lymphocyte proliferation test were used to detect the levels of specific antibodies,neutralizing antibodies,CD3+,CD4+and CD8+T lymphocytes in spleen cells and the proliferation of spleen lymphocytes after specific stimulation.The target protein with a size of about 69 kDa was expressed in the cells with a single band.The purified protein concentration was 0.407 g/L,and the purity was 82.32％.The results from transmission electron microscopy showed that E-Ferritin protein could be recombined into a particle structure with a particle size of about 50 nm.The results of mouse immune experiments showed that E-Ferritin protein had good immunogenicity.The average specific antibody titer of E-ferritin protein in serum was 1∶92 160 after immunization 42 d.The main subclass of antibody was IgGl.The results of flow cytometry showed that E-Ferritin as an immunogen could induce higher levels of CD4+and CD8+T lymphocyte immune response.In lymphocyte proliferation test,the level of specific stimulation in the vaccine group was significantly higher than that in the non-specific stimulation group.In conclusion,the dengue virus envelope protein ferritin nanoparticle vaccine constructed in this study has good immunogenicity,which can provide reference for the de-velopment of new dengue vaccine candidates.

Bluetongue virus(BTV)is classified as a category Ⅱ animal epidemic disease in China,infecting multiple species and posing significant threats to the ruminant breeding industry.There are 29 serotypes of BTV,with BTV16 being one of the major serotypes currently prevalent in Chi-na.Bluetongue virus infection mainly manifests as a latent infection,making the establishment of ELISA assays crucial for epidemiological detection.In this study;the expression of the BTV16 VP2 protein was achieved using a prokaryotic expression system,and polyclonal antibodies were pre-pared using BALB/c mice.An indirect ELISA assay using VP2 protein as the encapsulated antigen was established and optimized.Clinical samples from the Guangxi Zhuang Autonomous Region were tested and analyzed for compliance with commercial kits.The results showed that the BTV16 VP2 protein was successfully expressed and purified,and the prepared polyclonal antibody exhibi-ted good immunogenicity.The ELISA assay had good specificity,with no cross-reactivity against ruminant diseases such as AKAV,FMDV and GETV.The critical values for negativity and positivity were determined to be 0.314,and the coefficients of variation(Cv)between batches and within batches were both less than 5％,indicating good reproducibility.The ELISA assay revealed a positive rate of 92.4％for 79 samples from the Guangxi Zhuang Autonomous Region,with a compliance rate of 98.7％when compared to the commercialized kit.In conclusion,this study suc-cessfully established an indirect ELISA method for BTV16,facilitating the detection of bovine clin-ical samples.

Bluetongue virus(BTV)is classified as a category Ⅱ animal epidemic disease in China,infecting multiple species and posing significant threats to the ruminant breeding industry.There are 29 serotypes of BTV,with BTV16 being one of the major serotypes currently prevalent in Chi-na.Bluetongue virus infection mainly manifests as a latent infection,making the establishment of ELISA assays crucial for epidemiological detection.In this study;the expression of the BTV16 VP2 protein was achieved using a prokaryotic expression system,and polyclonal antibodies were pre-pared using BALB/c mice.An indirect ELISA assay using VP2 protein as the encapsulated antigen was established and optimized.Clinical samples from the Guangxi Zhuang Autonomous Region were tested and analyzed for compliance with commercial kits.The results showed that the BTV16 VP2 protein was successfully expressed and purified,and the prepared polyclonal antibody exhibi-ted good immunogenicity.The ELISA assay had good specificity,with no cross-reactivity against ruminant diseases such as AKAV,FMDV and GETV.The critical values for negativity and positivity were determined to be 0.314,and the coefficients of variation(Cv)between batches and within batches were both less than 5％,indicating good reproducibility.The ELISA assay revealed a positive rate of 92.4％for 79 samples from the Guangxi Zhuang Autonomous Region,with a compliance rate of 98.7％when compared to the commercialized kit.In conclusion,this study suc-cessfully established an indirect ELISA method for BTV16,facilitating the detection of bovine clin-ical samples.