STUDIES OF A MURINE STRAIN OF POLIOMYELITIS VIRUS IN COTTON RATS AND WHITE MICE

Area of Science:

• Virology
• Neuroscience
• Infectious Diseases

Background:

• Poliomyelitis virus (SK strain) is a known neurotropic pathogen affecting humans and primates.
• Understanding viral adaptation and cross-species infectivity is crucial for disease control.
• Previous research focused on primate models for poliomyelitis.

Purpose of the Study:

• To isolate and characterize a neurotropic virus from poliomyelitis virus in murine models.
• To investigate the pathogenicity and immunological relationship of the isolated murine virus to poliomyelitis.
• To explore the potential of the murine virus for immunization against poliomyelitis.

Main Methods:

• Isolation of a neurotropic murine virus by serial passage of poliomyelitis virus (SK strain) from monkeys to cotton rats and white mice.
• Cultivation of the murine virus in embryonic mouse brain tissue culture.
• Pathogenicity studies in various animal models (mice, cotton rats, albino rats, guinea pigs, rabbits, rhesus monkeys).
• Cross-neutralization assays using murine virus, poliomyelitis virus (SK and Aycock strains), and corresponding antisera.
• Immunization experiments in monkeys using live murine virus and subsequent challenge with poliomyelitis virus.

Main Results:

• A neurotropic murine virus was successfully isolated and adapted to mice and cotton rats.
• The murine virus produced symptoms and lesions comparable to poliomyelitis in monkeys and humans.
• The murine virus exhibited differential pathogenicity, being highly infectious for mice and cotton rats but not for albino rats, guinea pigs, or rabbits.
• Cross-neutralization tests confirmed the antigenic relationship between the murine virus and poliomyelitis virus (SK and Aycock strains).
• Immunization with live murine virus conferred partial resistance in monkeys against poliomyelitis virus infection.
• The presence of the murine virus in the central nervous system interfered with the propagation of poliomyelitis virus in monkeys.

Conclusions:

• The isolated neurotropic murine virus is antigenically related to poliomyelitis virus.
• This murine virus serves as a valuable model for studying poliomyelitis pathogenesis and for developing potential vaccines.
• The findings suggest a potential interference phenomenon between the murine virus and poliomyelitis virus within the host.