Prolonged Viral Antigen Retention in the Brain of a Gnotobiotic Dog Experimentally Infected with Canine Distemper Virus
Year: 1987
Type: article
Abstract: Chronic canine distemper virus (CDV) infection, expressed either as delayed-onset demyelinating encephalomyelitis (Old Dog Encephalitis, ODE) or as chronic polioencephalitis is a well known sequela to acute CDV infection, and may arise following an acute symptomatic episode, clinically inapparent infection, or vaccination.Delayed-onset encephalitis2 is distinguished by multiple sites of intracellular viral antigen deposition,' which occur in the presence of an antiviral immune response.f5It is presumed that delayed manifestations of CDV encephalitis involve persistent viral infection, although in most naturally occurring cases re-exposure to wild type virus cannot be excluded.Viral expression in these cases occurs in the presence of high titers of virus neutralizing antibody,6 similar to the situation in subacute sclerosing panencephalitis, a persistent measles virus infection of humans,6 and in CDV infection of mi~e.~,~Caninedistemper virus persistence may be a common event in recovered animals.Observations indicate elevated titers of antiviral antibody are sustained for long periods of time following live-virus vaccination of conventional dogs sheltered from contact with virus, in contrast to the limited antiviral response of conventional dogs immunized with killed CDV.9These observations, together with reports of CDV isolation from tissues of apparently normal dogslo and preliminary evidence of prolonged antiviral immunoresponsiveness in gnotobiotic dogs (unpublished observations) suggest continual restimulation of the host's immune system by viral antigens following contact with live but not killed virus.This immunological evidence is supported by the presence of sev-
Source: Veterinary Pathology
Authors: G. C. Johnson, S. Krakowka, M. K. Axthelm
Language: English
Topic: Virology and Viral Diseases
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1509752143