Construction of a Recombinant Bovine Herpesvirus 4 as a Delivery System for Ovine Herpesvirus 2 Glycoprotein B

Primary author: Emily Cole
Faculty sponsor: Dr. Cristina Cunha

Primary college/unit: College of Veterinary Medicine
Campus: Pullman


Ovine herpesvirus 2 (OvHV-2) causes a frequently fatal disease called malignant catarrhal fever (MCF) in several ungulates, such as bison, cattle, pigs and deer. Vaccine development is a major goal for MCF research because there are no treatment options. However, the inability to propagate OvHV-2 in in-vitro systems has hindered the development of a vaccine. Since the virus cannot be modified or attenuated in-vitro, alternative approaches for delivering OvHV-2 antigens for immunization are of utmost importance. OvHV-2 glycoproteins, gB, gH, and gL, are necessary for viral entry and can stimulate neutralizing antibody responses capable of protecting animals from disease. This makes them ideal vaccine candidates. Additionally, bovine herpesvirus 4 (BoHV-4) has been evaluated as a vaccine vector for several viral diseases with promising results in delivering heterologous antigen that confer immunity.The purpose of this study was to construct and evaluate a recombinant BoHV-4 for the expression of OvHV-2 gB. To do this, the bacterial artificial chromosome recombineering galK selection system was used and confirmed with PCR, sequencing, and restriction enzyme digestion. Then viral growth curves were used to assess reconstitution of the infectious virus in various cell types. Also, western-blot analysis and immune-fluorescence assays were used to confirm OvHV-2 gB expression. The construction of this recombinant BoHV-4 virus will allow further MCF research regarding vaccine efficacy, as this vector virus could provide a means of delivering OvHV-2 gB in vivo. Vaccine development is vital considering this is an untreatable, global disease that economically effects agriculture, particularly bison production.