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Expression of poliovirus receptor in human spinal cord and muscle
M E Leon-Monzon1, I Illa, M C Dalakas
1Medical Neurology Branch, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
Abstract:
Because a prerequisite for infection of a cell with the poliovirus is the presence of poliovirus receptor (PVR), we examined its tissue localization in the human muscle, spinal cord, and muscle cultures using a specific monoclonal antibody against PVR in immunocytochemical studies on serial sections. We found weak expression of PVR in the motor neurons but not the axons. In normal muscle, PVR was expressed at the end plate as confirmed by immunolocalization in serial sections with alpha-bungarotoxin. In neurogenic conditions and in myopathies, PVR was found in occasional denervated muscle fibers and in several regenerating ones. Human myotubes expressed PVR and were susceptible to the poliovirus infection. We conclude that PVR is present at the motor end-plate that can serve as one of the routes of entry of the virus to the motor neurons. The presence of PVR in the regenerating muscle fibers is in accord with clinical observations that muscle injuries can predispose patients to paralytic poliomyelitis.
Insights
Poliovirus receptor (PVR) is present in human motor neurons and muscle end plates, facilitating poliovirus entry. Regenerating muscle fibers also express PVR, explaining how muscle injuries can increase susceptibility to paralytic poliomyelitis.
Area of Science:
- Neuroscience
- Virology
- Immunology
Background:
- Poliovirus infection requires poliovirus receptor (PVR) expression.
- Understanding PVR tissue distribution is crucial for elucidating poliovirus pathogenesis.
Purpose of the Study:
- To investigate the tissue localization of PVR in human muscle and spinal cord.
- To determine PVR expression in normal, neurogenic, and myopathic muscle conditions.
- To assess the susceptibility of human myotubes to poliovirus infection.
Main Methods:
- Immunocytochemical studies using a specific monoclonal antibody against PVR.
- Analysis of serial sections from human muscle and spinal cord.
- Immunolocalization using alpha-bungarotoxin to identify motor end plates.
Main Results:
- Weak PVR expression was observed in motor neurons, but not axons.
- PVR was localized at the motor end plate in normal muscle.
- PVR was found in denervated and regenerating muscle fibers in neurogenic conditions and myopathies.
- Human myotubes expressed PVR and were susceptible to poliovirus infection.
Conclusions:
- The motor end plate serves as a potential entry route for poliovirus into motor neurons.
- PVR expression in regenerating muscle fibers correlates with increased susceptibility to paralytic poliomyelitis following muscle injury.