Prediction Of FMDV Various Types Epitope In Embedded Protein SLP-Multi VP1 And Effects On IgG Subtypes In Different Strain Mice

Foot-and-mouth disease(FMD) is a kind disease with huge infectivity, mainly caused by FMDV(Foot-and-Mouth Disease Virus), and cloven-hoofed animals are susceptible. It has caused economic loss in livestock breeding. With the rapid development of biotechnology, the FMD vaccines has shifted from traditional vaccines to new vaccine, like the epitope vaccine, which has presented many advantages, such as, be identified and combined by MHC molecular that has a variety of genetic background easily, then, transport the antigen efficiently. So, it holds advantages when dealing with the variability of pathogenic microorganisms and the complex process of immune response. Our experiment as follows:1. The three-dimensional structure of embedded protein SLP-Multi VP1 was successfully predicted by Swiss-Model and Swiss-Pbd Viewer through acquired amino acid sequence of the embedded-type protein SLP-Multi VP1, and three FMDV epitope sites were marked.2. 6-weeks-old Kunming mice were vaccinated by embedded protein SLP-Multi VP1 and recombinant protein SLP, PBS was injected as negative group. After three times of vaccination, lymphocytes of the spleen tissue was isolated. Treated by established methodologies, and the quantity of CD4+ and CD8+ T cell of each group was analyzed by flow cytometry. The results showed that: the number of CD4+ and CD8+ T cell of vaccinated group were much higher than and PBS group, and the difference was significant(P<0.05). The results suggested that the embedded protein SLP-Multi VP1 can induce immune response.3. 6-week-old BALB/ and Kunming mice were immunized by embedded protein SLP-Multi VP1 and recombinant protein SLP, then the Ig G levels of each group were determined by indirect ELISA assay. The results suggested that SLP-Multi VP1 protein can stimulate two kinds of mice to produce high level of Ig G, showed good antigenicity, and there was no significant difference between BALB/c and Kunming groups on Ig G level(P>0.05), which showed no existence of species specificity.4. Collected the serum of BALB/c and Kunming mice after the third immunization and Ig G subtypes was detected by ELISA kit, then analyzed with SPSS. Results showed: In both mice immunized animal model, the Ig G2 a and Ig G1 level of the embedded protein SLP-Multi VP1 group was higher than SLP immunized group, and the difference was significant(P<0.05). In addition, the level of Ig G2 a was much higher than Ig G1(P<0.05) in embedded protein SLP-Multi VP1 immunized group. In SLP group, the level of Ig G1 and Ig G2 a were no difference(P>0.05), the results suggested that embedded protein SLP-Multi VP1 tend to stimulate Th1 type cell-mediated immune response.This study provide views for further research about characteristic of each types of FMDV VP1 epitope embedded with SLP-Multi VP1 protein.