The Characterization of Neutralizing and Non-neutralizing Monoclonal Antibodies against Equid Herpesvirus Type 1

Seven monoclonal antibodies (MAbs) were produced which recognized equid herpesvirus type 1 (EHV-1). Three MAbs neutralized the subtype 1virus (strain Army 183) in the presence of complement, but did not neutralize the subtype 2 virus (strain MD). All three MAbs immunoprecipitated an Mr 83K glycoprotein from a detergent-solubilized virion envelope preparation of the subtype 1 virus. The target antigens of the four non-neutralizing MAbs (6Fll, 2A4, 1F10 and 8D9) were identified by immunoblotting a ainst purified EHV-1 virions and had respective apparent Mr values of> 205K,> 205K, 97K and 13K. Equid herpesvirus type 1 (EHV-1) is a member of the alphaherpesvirus group, and is composed of two subtypes. In the natural host, subtype 1viruses are associated with respiratory disease, abortion and paresis, whereas subtype 2 viruses are predominantly associated with respiratory disease (Allen & Bryans, 1986). Immunity stimulated by natural infection or vaccination is generally short-lived and, consequently, horses may suffer repeated infections resulting in serious economic losses to the equine industry. Although there is considerable antigenic cross-reactivity between the two subtypes of EHV-