Secreted expression of nonstructural protein gene 3ABC of foot-and-mouth disease virus in Sf9 cells and activity analysis / 生物工程学报

Entire 3ABC sequence of FMDV containing a 6 x his tag coding sequence at the N-terminal was obtained through PCR amplification using a pair of specific primers, subcloned into shuttle plasmid of pMelBac-B with a melittin secretion signal sequence and finally constructed recombinant plasmid of pMel-3ABC. After co-transfected the recombinant plasmid and linearized Bac-N-Blue DNA into Sf9 insect cell under intermediary agent of the Cellfectin, the result showed that we have already acquired recombinant baculovirus by screen of plaque assay and identification of PCR. Though the recombinant baculovirus infecting the Sf9 cells again, experiments indicated that 3ABC gene could express in insect cells and the expressed protein was secreted in the supernatant of Sf9 cell culture possessing favourable biological activities detected by adopting two methods of SDS-PAGE and Western blot. The result verified that the protein could respond with sera derived from FMDV infected animals, but have no responsibility with sera derived from health animals and vaccinated animals detected by indirect ELISA using antigen of expressed protein after purification with Ni-NTA his bind resin. Therefore, this study has established a solid foundation for establishing an effective diagnosis method to discriminating the FMDV infected animals from vaccinated animals.

Comparison of Three ELISA Kits for the Differentiation of Foot-and-mouth Disease Virus-infected from Vaccinated Animals / 中国病毒学

A study was performed to validate 3 FMDV 3ABC-I-ELISA kits developed in China for the differentiation of FMDV infected and vaccinated animals.Sets of sera from naive and vaccinated cattle as well as from cattle that had been infected were tested for antibodies against nonstructural proteins (NSPs) of FMDV by commercial diagnosis kits,Ceditest(R)FMDV-NS (Ceditest(R) kit),UBI(R) FMDV NONSTRUCTURAL PROTEIN ELISA DIRECTION INSERT (UBI(R) kit) and a FMDV 3ABC-I-ELISA kitdeveloped at the Lanzhou Veterinary Research Institute.The test parameters (sensitivity and specificity) of the three kits were determined,and the result obtained from FMD 3ABC-I-ELISA kit was compared with that obtained from two foreign kits.The results indicated that the coincidence rate between the FMDV 3ABC-I-ELISA and Ceditest(R) kits was 98.05%,and the coincidence rate between the FMDV 3ABC-I-ELISA and UBI(R) kits was 94.4%; the sensitivity of both Ceditest(R) and FMDV 3ABC-I-ELISA kit was 100%.However,the sensitivity of the UBI(R) kit was only 81.8%.With sera from naive or vaccinated non-infected animals,the specificity of all tests exceeded 90%.

Prediction of Secondary Structure and B Cell Epitope for Capsid Protein of SVDV / 中国生物工程杂志

The secondary structure of Capsid protein was predicted by the methods of Chou-Fasman,Garnier-Robson and Karplus-Schultz based on the sepuence of capsid protein gene of Swine Vesicular Disease Virus (SVDV) and hydrophilicity. Surface probility plot and antigenic index for capsid protein were obtained by the methods of Kyte-Doolittle, Emini and Jameson-wolf, respectively, Combining the results according to these methods, the B cell epitopes for capsid protein of SVDV were predicted. The results showed that there are much flexible region such as coil region and turn region in capsid protein of SVDV, there are more predominant B cell epitopes in VP1 than in VP2 and VP3. This study would be helpful for identification of B cell epitopes for capsid protein using experimental methods and research of reverse vaccine of SVDV.

Expression of recombinant plasmid pcDNA3.1/P12X3C with multi-genes of foot-and-mouth disease virus in BHK-21 cells / 生物工程学报

In order to obtain the gene P12X3C of Foot-and-Mouth Disease Virus (FMDV) that includes full length P1, 2A, 3C and a part of 2B, the site mutation strategy was used. After being digested by Kpn I and Xba I respectively, the gene P12X3C was cloned into the pcDNA3.1 (+) expression vector. The recombinant plasmid was checked by restriction enzyme analysis and nucleic acid sequencing, and then named pcDNA3.1/P12X3C. Further, BHK-21 cells was transfected with pcDNA3.1/P12X3C by using lipoid. The proteins of Foot-and-Mouth Disease Virus, which were expressed in BHK-21 cells, were confirmed by sandwich-ELISA and fluoroscopy. The result shows the gene P12X3C is cloned into eukaryotic expression plasmid, and the recombinant eukaryotic expression plasmid pcDNA3.1/P12X3C could express proteins of Foot-and-Mouth Disease Virus in BHK-21 cells, which have immunocompetence. This study demonstrates that delivery of a recombinant eukaryotic expression plasmid containing P12X3C coding regions results in the assembly of FMDV capsid structures, which will offer experimental base to DNA vaccine of FMDV.

Recent Advances on Reverse Genetics of Foot-and-mouth Disease Virus / 微生物学通报

Usage of reverse genetic techniques in the research area of the fundamental etiology of foot-and-mouth disease virus (FMDV), has resolved the issue about the function of viral gene of FMDV on genomic integer level. At present, a further recognition and apprehension for the molecular etiology of FMDV based on the development in reverse genetics was made. Combined with the research work in our labs, we reviewed international advances about the molecular pathogenic mechanism, the relationship be-tween virulence and variation in the genomes, influencing factors for the viral replication, and the develop-ment of new-type gene vaccine of FMD in this article, and propose the potential research aspects in reverse genetics of FMDV in the future.