Primary Development Of The Genetic Engineering Vaccine Against Foot-and-mouth Disease Virus

1,Comparison of Three Assays for detection of antibodiesagainst Foot-and-Mouth Disease Virus Serotype OAntibody level of 125 sera from farms were detected by two ELISA and a IHAassays for detection of antibodies against Foot-and-Mouth Disease Virus Serotype O.The coincidence rate and repeatability of three kits were analyzed o The results indictthat antibody level determined by three kits showed good accordance. The resultsdetected by three kits repeat well.2,Synthesis, expression of representative VP1 gene of FMDVtype O and detection of expression product immunogenicityThe VP1 gene of FMDV type O was designed and synthesized artificiallyaccording to gene sequences of FMDV genetic group 1 that is close relative to diseasecontrol in our country by homology comparison among FMDV oligonucleotidesequence that were published by GeneBank in the past ten years. And the expressionplasmid carrying VP1 gene was obtained by the technology of genetic engineering.The expression vector was transformed into BL21 (DE3)LysS. VP1 was expressed inBL21(DE3)lyss and was analyzed by SDS-PAGE and Western-blot. The resultshowed that the recombinant protein found in inclusion bodieso It had a molecularweight of approximately 30 KD, and the protein was able to react with FMDVpositive serum. The protein was used to vaccinate mice, whose immune responseswere then observed. The protein could induce serum antibody. 3,Expression and immunogenesity analysis of a recombinantfusion protein of LTB and VP1LTB gene fragment was amplified by PCR from plasmid PMDLT, Arecombinant expression plasmid pETLTBVP1 was constructed by inserting LTB genefragment into VP1 gene expression vector pETVP1that was constructed in the secondexperiment. The recombinant expression plasmid pETLTBVP1 was transformed toBL21(DE3)LysS for expression. Identify the expressed product by SDS-PAGE andanalyze its immunoreactivity by Western blot. The results showed the molecularweight of fusion protein was about 39 KD, and the recombinant protein was found ininclusion bodies; The fusion protein was able to react with FMDV positive serum andanti-CT serum of rabbit. Animal experiment result showed that, compared withconventional inactivated vaccines, this fusion protein elicited higher antibody levelsof serum antibody.4,Enhancing Effect of B Subunit of Escherichia coli Heat-labileEnterotoxin on Mucosal Immunity of FMDV VP1 ProteinThe VP1 protein of FMDV type o and fusion protein of VP1 with LTB wereobtain under IPTG induction. The expressed proteins were purified, and Mice wereinoculated with purified proteins VP1 proteins and LTB-VP1 fusion protein by directnasal drops, stomach delivery and rectal instillation respectively, and the antibodylevels of Mice was detected. The results showed that the anti-FMDV antibody in seraof mice immunized with LTB-VP1 fusion protein was higher than mice immunizedwith VP1protein in all of the immunity groups.