Glycoprotein-specific immune responses in cats after exposure to feline herpesvirus-1

To obtain synchronous infection, 10 cats were inoculated with feline herpesvirus-1 (FHV-1) on the oral, nasal, and conjunctival mucosa. Swab specimens of the nasal, conjunctival, and pharyngeal mucosa were obtained for virus isolation from each cat before inoculation and at 3-day intervals thereafter until postinoculation day 21. Recovery of virus and evidence of clinical signs were used to document FHV-1 infection. Serum was obtained from blood samples collected sequentially from each cat between day 0 and postinoculation day 90. Virus-neutralizing antibody titer was determined in all serum specimens. Immunoprecipitation with [35S]methionine- and [14C]glucosamine-labeled viral antigens, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was performed on each specimen. Three precipitation bands with approximate molecular weights of 105,000, 68,000, and 60,000 were separated from [14C]glucosamine- and [35S]methionine-labeled immunoprecipitates. The concurrent detection of virus-neutralizing antibody and glycoprotein-specific immunoprecipitins implied that in cats, the FHV-1 glycoproteins were important in the induction of virus-neutralizing antibodies to FHV-1.