Prokaryotic Expression And Immunological Characteristics Studies Of The GD Gene From Infectious Bovine Rhinotracheitis Virus

Infectious Bovine Rhinotracheitis Virus(IBRV),also known as Bovine herpesvirus type 1(BHV-1),causes an acute,febrile and contact infectious disease after infecting cattle,mainly with high fever,dyspnea,rhinitis,sinusitis and upper respiratory tract inflammation,known as Infectious Bovine Rhinotracheitis(IBR),also known as "red nose disease" or "necrotic rhinitis"[1].World Organisation for Animal Health(OIE)lists IBR as a statutory report animal disease.gD protein is the main structural protein of IBRV,which can induce humoral and cellular immunity at the same time.gD also plays an important role in the process of virus adsorption and invasion into host cells.It is the essential gene for virus replication and the main glycoprotein that stimulates the body to produce neutralizing antibodies.Therefore,gD is the first choice for the study of IBRV specific antigens in all IBR proteins.This study was based on IBRV isolated from the pastures in Hohhot in 2017 and was named IBRV NMHS-1.Using the IBRV NMHS-1 genome as a template,primer-specific amplification of gD gene was designed and linked to the expression vector pET32(+).The recombinant vector was successfully constructed,and the induction conditions were optimized to make the recombinant protein soluble expression.An animal model of IBRV NMHS-1 was established by successfully infecting rabbits.The purified recombinant protein was prepared into a vaccine,and animal immunity test was carried out on rabbits.Experiments showed that rabbits successfully resisted the virus infection after two immunizations.Western Blot proved that the recombinant protein had good reactogenicity,and indirect ELISA was used to detect the titer of rabbit serum antibody,which proved that the recombinant protein had good immunogenicity.In summary,this study successfully isolated a strain IBRV and named as IBRV NMHS-1 strain.The gD gene was successfully induced and expressed,and the gD protein expressed in soluble form.IBRV NMHS-1 successfully infected rabbits to establish an animal model and the prepared subunit vaccine can effectively protect experimental animals from virulent attack.It provides a possibility for the development of IBRV subunit vaccine.