Effects of canine distemper virus infection on lymphoid function in vitro and in vivo.

In the present study, the immunodepressive effects of canine distemper virus (CDV) infection of dogs on two parameters of lymphocyte function, namely phytomitogen-induced cellular proliferation and skin allograft rejection, were investigated. Infection of susceptible gnotobiotic dogs with virulent R252-CDV resulted in a depression of peripheral blood lymphocyte mitogen response as measured by (3H)thymidine incorporation for up to 10 weeks after inoculation. This effect coincided with the appearance of viral antigen by immunofluorescence in leukocytes but persisted after the virus was no longer detectable.

Biological properties of a canine distemper virus isolate associated with demyelinating encephalomyelitis.

A canine distemper virus (CDV), DESIGNATED R252, originally recovered from a dog with demyelinating encephalomyelitis was shown to reproduce this disease in gnotobiotic dogs with a high incidence as compared to other CDV strains, which produced an acute fatal infection. In this investigation, R252 was propagated for the first time in Vero cells and compared to two known strains of CDV, Snyder-Hill (SH) and Onderstepoort (Ond). The results of this study revealed that intracellular R252 accumulated more slowly than either SH or Ond.

Experimental canine distemper virus-induced lymphoid depletion.

Thirty-four gnotobiotic dogs were used to study the effects of R252 canine distemper virus (CDV) infection on the lymphoid system. Twenty-one dogs were inoculated parenterally, and 6 dogs were infected by contact exposure to inoculated littermates. Seven littermate dogs were maintained as uninfected controls.

Myelin-specific autoantibodies associated with central nervous system demyelination in canine distemper virus infection.

Sera from dogs with spontaneously occurring and experimentally produced canine distemper virus-associated demyelinating encephalitis were examined for antibodies to central nervous system myelin by the complement fixation and indirect immunofluorescent methods. Complement-fixing immunoglobulin M antibodies and non-complement-fixing immunoglobulin G antibodies were found in 97% of the spontaneous cases. In comparison, only 28% of control sera contained these antibodies; furthermore, mean antibody titers in the control groups were significantly lower (P < 0.