The aim of the project is to define the contribution of individual glycoproteins to protective immunity to herpesviruses. Central is the development of an engineered vaccine to bovine Herpesvirus type 1 (BHV1). Antigenic and immunogenic properties of herpesviral glycoproteins will be tested following expression of individual genes by vaccinia recombinants and subsequent immunization of cattle.
Highly specific and sensitive tests were developed to study mucosal immunity after bovine herpesvirus type 1 (BHV-1) vaccination and infection, to identify viral glycoproteins including a specific cytotoxic T-lymphocyte (CTL) response in herpesvirus infected animals and to evaluate the contribution of individual glycoproteins of BHV-1 and glycoprotein B of murine cytomegalovirus were isolated and, with the exception of the ORF for gE(BHV-1), integrated into the genome of vaccinia virus.
Tests were developed to study the antibody responses against BHV-1 on the mucosae of infected or vaccinated cattle. If this mucosal immunity is correlated with the induced protection by vaccination, which is presently determined in challenge experiments, it may make the severe experimental infections in cattle no longer necessary. Concerning the design of a BHV-1 marker vaccine that contains a deletion of a nonessential glycoprotein gene, the results obtained so far with the recombinant vaccinia viruses indicate that both gG and gI are not suitable for this purpose because gG shows a significant strain heterogeneity in the amino acid sequence and gI appears to be at least weak immunogenic with respect to the humoral immune response.
Herpesvirus associated diseases cause high economic losses in the farm animal husbandry and are highly prevalent in the human community. Virus diseases of the respiratory tract present a threat to cattle husbandry. Frequently bovine Herpesvirus type 1 is involved and is considered the major infectious agent, capable of producing alone a respiratory disease. This herpesvirus causes two clinical syndromes:
a disease (infectious bovine rhinotracheitis, IBR) characterized by rhinitis and tracheitis, fever, a drop in milk production and abortion;
a veneral disease (infectious pustular vulvovaginitis/ balanopostitis, IPV) characterized by pustular lesions of the genital tract of cows and bulls.
The goals of the project are to determine the prerequisites for the development of an engineered vaccine to bovine Herpesvirus type 1 (BHV1) by defining the contribution of individual glycoproteins to protective immunity and to construct deletion mutants of BHV1 that provide the basis for a safe and efficacious vaccine. The immunological role (isotype specific systemic and mucosal antibody response, cell mediated immunity) of isolated herpesviral glycoproteins will be studied in vitro and in vivo using small laboratory animals and cattle. Each of the genes coding for the probably nonessential glycoproteins gC, gE, gG and gI (nomenclature of the herpes simplex homologs) will be deleted from the viral genome and the resulting viral variants will be tested for virulence in specified pathogen free calves. The combined immunological, pathological and molecular biological results will be used to fotmulate the requirements for a second generation vaccine against BHV1 infections of cattle.
Funding SchemeCSC - Cost-sharing contracts
8200 AB Lelystad