Study On Imunnological Enhancement Of Two Th Epitope On The Synthetic Peptide Vaccines Of Type O Foot And Mouth Disease

Foot-and-mouth disease（FMD）is a kind of highly contagious and highly fatal disease of cloven-hoofed animalscaused by Foot-and-Mouth Disease Virus（FMDV）.Since the virus research,found seven different kinds of foot-and-mouth disease virus serotype,respectively is O,A,C,Asia1,SAT1,SAT2,and SAT3.Bcecause of many reasons,just like FMDV is spread through sexual contact,the frequency of mutation is very high,and the existing vaccine immunization effect is not perfect,all bring some difficuties in prevention and treatment work about Foot-and-mouth disease in worldwide.By reference to previous research results in the related fields of vaccine adjuvants,we use modern virus analysis software to predict and design two Th epitope groups.Made a tentative study about wheather the Th epitopes have the immune enhancement effect of FMDV synthetic peptide vaccine.In ehe study,we explored and compared the differences of the enhancement effect of different molecular size and framents.In the experiment,we query the Th epitope sequence in NCBI,do the homologous comparison used the DNAMAN 7.0 software,and designed two Th eritope sequences which respectively located in structural protein VP1 protein and non-structural protein 3D protein of FMDV,and connected two sequences in series.Then add the peptide monomer ang series to the synthetic peptide antigen of FMDV,and prepared FMD vaccine emulsion.Finally,immune six week old female BALB/c mice,at the same time,we established the indirect ELISA for detection the antibody of VP1,meanwhile,using MTT assay,flow cytometry parting,cytokine ELISA detection,paraffin method to evaluae the immune enhancement of the two Th epitopes.ELISA-VP1 result shows that Group A added Th_3Dand Group B added Th_3D+Th _VP1epitope peptide can significantly enhance the OD level of VP1 after 14 d and 21d of second immune in serum.Cytokines test shows that:Th_3Dand Th _3D+Th _VP1epitope peptide can significantly improve the level of IFN–gamma and IL-4 in mice serum,and Th_3D+Th_vp1epitope peptide significantly reduced the level of IL-10 in mice serum.In the tissue slice,Group A added Th_3Dand Group B added Th_3D+Th _VP1epitope peptide can inflammed germinal zones ation.Also,these two group increased white pulp part volume and T lymphocyte proliferation rate obviously.The number of CD4⁺T cells of Group B added Th_3D+Th _VP1epitope peptide was 36.21%,which was the highest one.The lowest one was23.495%in the control group.This study compared the immune enhancement effect of two groups of Th epitope peptide with FMDV-O peptides.It can provide reference and reference for FMDV vaccine research.In addition,this experiment shows that Th_3Dand Th_3D+Th _VP1epitope peptide can induce the response of cellular immunity and humoral immune in the body.This study provide strong material for 3 d protein VP1 protein study、prevention and treatment of FMDV.This study has the value of research and practice.