With the development of vaccine research and development technologies, novel vaccines have been widely used in the prevention of various infectious diseases. Due to the excellent safety, novel vaccines have unique advantages in the application of vaccines against virulent pathogens. The major premise of developing novel vaccines is to screen protective antigens. With the development of various omics research, cutting-edge bioinformatics tools for eukaryotes have been well developed, while the much simpler structure of viruses compared with eukaryotic cells corresponds to relatively simple research methods. Strategies for screening protective antigens need to combine the advantages of both bioinformatics methods and traditional molecular biology methods. In this review, the strategies for screening virus protective antigens were discussed from the perspective of host and virus, and a series of bioinformatics tools developed based on eukaryotic cells that may be used for screening protective antigens were listed. This review also summarized the cases of using protective antigens to design novel vaccines, in order to better understand the strategies for screening virus protective antigens and facilitate the research and development of novel vaccines.
Antigens ; Antigens, Viral/genetics* ; Computational Biology ; Research ; Vaccines ; Viral Vaccines/genetics*

Antigens, Viral ; genetics ; Humans ; Mutation ; Orthomyxoviridae ; classification ; genetics ; immunology

OBJECTIVETo clone the glycoprotein G gene and its specific fragment with high conservation and antigenicity by culturing and amplifying herpes simplex virus type 2 and extracting its whole genome.

METHODSWe obtained a great deal of suspension with HSV-2 virus after infecting the cultured Hela cells with HSV-2 virus, extracted the whole genome of the virus by the phenol-chloroform method, and amplified the US4 gene coding gG-2 by PCR. Then we selected the specific target fragment according to the amino acid sequence alignment of the gG-2 gene and cloned it with the designed primers with restricted endonuclease sites.

RESULTSWe successfully obtained a lot of suspension with HSV-2 virus, and cloned the gG-2 gene from the whole genuine and its specific target fragment. Sequencing showed that both the sequences were identical with those printed in the GenBank.

CONCLUSIONIt is feasible to obtain the virus genome and specific fragment of the gG-2 gene from virus-infected cells, especially for HSV-2 virus with relatively stable hereditary trait. It has prepared the ground for further constructing the expression plasmid of the specific fragment, expressing related proteins and identifying their antigenicity.

Antigens, Viral ; genetics ; Cloning, Molecular ; DNA, Viral ; HeLa Cells ; Herpesvirus 2, Human ; genetics ; Humans ; Viral Envelope Proteins ; genetics ; Virus Cultivation

Foot-and-mouth disease (FMD) is an acute, severe, and highly contagious infectious disease caused by foot-and-mouth disease virus (FMDV), which seriously endangers the development of animal husbandry. The inactivated FMD vaccine is the main product for the prevention and control of FMD, which has been successfully applied to control the pandemic and outbreak of FMD. However, the inactivated FMD vaccine also has problems, such as the instability of antigen, the risk of spread of the virus due to incomplete inactivation during vaccine production, and the high cost of production. Compared with traditional microbial and animal bioreactors, production of antigens in plants through transgenic technology has some advantages including low cost, safety, convenience, and easy storage and transportation. Moreover, since antigens produced from plants can be directly used as edible vaccines, no complex processes of protein extraction and purification are required. But, there are some problems for the production of antigens in plants, which include low expression level and poor controllability. Thus, expressing the antigens of FMDV in plants may be an alternative mean for production of FMD vaccine, which has certain advantages but still need to be continuously optimized. Here we review the main strategies for expressing active proteins in plants, as well as the research progress on the expression of FMDV antigens in plants. We also discuss the current problems and challenges encountered, with the aim to facilitate related research.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Foot-and-Mouth Disease/prevention & control* ; Antigens, Viral/genetics* ; Viral Vaccines

E2 gene of classical swine fever virus (CSFV) was cloned into secretory pPIC9K Pichia pastoris expression vector. After being linearized by digestion, the vector was transformed into Pichia pastoris by electroporation to integrate with the genome, the transformants with high copies were screened by G418 and were induced to express with methonal. The results of SDS-PAGE and Western blot demonstrated that the supernatant of the induced P. pastoris culture contained protein E2. The results of the study on the immunological activity indicated that the protein E2 expressed in P. pastoris can elicit animal bodies to produce antibodies against protein E2.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Classical swine fever virus ; genetics ; immunology ; Cloning, Molecular ; Gene Expression ; Pichia ; Rabbits ; Swine ; Viral Envelope Proteins ; genetics ; immunology

BACKGROUNDTo determine the antigenicity of HGV NS5 recombinant proteins expressed in E.coli.

METHODSHGV NS5a,NS5b and core/NS5b fusion genes were cloned into pThioC vector. Three expression plasmids were transformed into JM109(DE3) competent cells then expressed with induction by IPTG. Western blot and ELISA were used to determine the antigenicity after the three recombinant proteins were purified.

RESULTSAfter identification by restriction enzyme and sequencing, it was confirmed that the expressed was target proteins espected. Purified expression proteins were found strongly immunoreactive among anti HGV positive sera by Western blot and ELISA. Compared with mixed recombinant antigen (including core, NS5a synthetic peptide and NS3 recombinant proteins), in the 22 positive sera detected with mixed antigen, 68%(15/22), 90%(20/22) and 73%(16/22) were positive by P5a,P5b and Pc?5b antigens; In the 70 negative samples with mixed antigen, 7%(5/70), 1%(1/70) and 6%(4/70) were positive by P5a, P5b and Pc?5b antigens. The positive alone was found among RTPCR positive specimen using these recombinant antigens.

CONCLUSIONSNS5 gene expressed in E.coli?which couldn't be covered with other regions of antigens was one of the essential epitopes to HGV immunologic diagnosis.

Antibodies, Viral ; blood ; Antigens, Viral ; blood ; Epitopes ; immunology ; GB virus C ; genetics ; immunology ; Humans ; Plasmids ; genetics ; Recombinant Proteins ; biosynthesis ; immunology ; Viral Nonstructural Proteins ; genetics ; immunology

OBJECTIVETo construct the virus-like parcel expressing hepatitis B virus (HBV) C gene and identify its immunogenicity.

METHODSHBV C gene was cloned into the shuttle vector pSC11, and the resulted plasmid pSC11-C was transfected into modified vaccinia virus Ankara (MVA).

RESULTSpSC11-C was correctly constructed as verified by sequence analysis and PCR, and the recombinant virus-like parcel possessed good immunogenicity.

CONCLUSIONThe MVA-C expressing HBV C gene has been successfully constructed to provide important basis for gene therapy research of chronic HBV infection.

Genes, Viral ; Genetic Vectors ; Hepatitis B Core Antigens ; genetics ; Recombination, Genetic ; Vaccinia virus ; genetics

BACKGROUNDTo obtain thermal stable, soluble, biologically active hepatitis E virus recombinant antigen using thioredoxin fusion expression system.

METHODSHEV ORF2 gene fragment (6964-7126 nt) was inserted into thioredoxin fusion expression vector pThioHisA. The recombinant plasmid was transformed into E. coli BL21 strain. After induction with IPTG, cells were lysed and the supernatant was subjected to 80 degree treatment for 10 minutes. After centrifugation, the supernatant was tested by ELISA.

RESULTSSDS-PAGE analysis showed the thioredoxin. HEV fusion protein was highly expressed and was thermally stable, soluble. HEV specific ELISA confirmed this fusion protein possessing HEV specific antigenicity.

CONCLUSIONSUsing thioredoxin fusion expression system, a soluble, thermal stable, biologically active HEV recombinant antigen was successfully expressed.

Antigens, Viral ; biosynthesis ; genetics ; Gene Expression ; Genetic Vectors ; Hepatitis E virus ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Thioredoxins ; genetics ; Viral Proteins ; biosynthesis ; genetics

OBJECTIVETo express main neutralization antigen VP7 of human rotavirus serotype G2 and G3 by recombinant adenoviruses on the basis of previous investigation of the prevalence of rotavirus in China.

METHODSOn the basis of successfully expression of human rotavirus protein G1VP7 by recombinant adenovirus vector, the authors constructed some potent recombinant adenovirus strains encoding rotavirus G2 VP7 and G3 VP7 genes which belong to the main rotavirus isolates 97S43 and 97S48.

RESULTSReplication defective recombinant adenoviruses expressing human rotavirus serotype G2 and G3 VP7 genes, named as rvAdG2VP7 and rvAdG3VP7 were successfully constructed. VP7 genes integrated into the viral genome were identified by PCR and Southern blot assay, and specific transcription were detected by RT-PCR in the 293 cells infected with recombinant adenoviruses. Expression of rotavirus VP7 proteins was demonstrated by Western blot assay.

CONCLUSIONThe established recombinant adenoviruses expressing G2 and G3 serotype VP7s laid a significant basis for further animal experiments in the development of multivalent rotavirus vaccines against rotavirus infection.

Adenoviridae ; genetics ; Antigens, Viral ; biosynthesis ; genetics ; Capsid Proteins ; biosynthesis ; genetics ; Humans ; Recombination, Genetic ; Rotavirus ; genetics ; isolation & purification

Antigens, Viral ; genetics ; metabolism ; Cell Line ; Cell Phone ; Gene Expression Regulation, Viral ; radiation effects ; Herpesvirus 4, Human ; physiology ; radiation effects ; Humans ; Immunohistochemistry ; Viral Proteins ; genetics ; metabolism