Pathogenicity of Mengo virus to mice. III. Potentiation of infection by immunosuppressants.

Mengo virus has been described to cause, in dependence on the virus dose, lethal panencephalomyelitis and exocrine pancreatitis in mice after i.p. inoculation. Two immunosuppressive agents, cyclophosphamide and 1,3-bis(piperidinomethyl)-5-ethyl-5-phenyl-barbituric acid (ZIMET 176/68), were shown to potentiate Mengo virus infection as demonstrated by histopathology and enhanced mortality. Organotropism of Mengo virus did not change under the drug treatment. However, the histological lesions in brain, spinal cord and pancreas failed to exhibit any inflammatory reaction in case of cyclophosphamide, due to its antiphlogistic properties. Considering the mode of action of the drugs employed and the pathogenesis of Mengo virus infection in mice, it is concluded that in the system used both cyclophosphamide and ZIMET 176/68 exert their potentiating effects by interfering with primary virus-macrophage interaction.