Related Experiment Videos
Polyomavirus-infected oligodendrocytes and macrophages within astrocytes in progressive multifocal
R Mesquita1, M Björkholm, M Ekman
1Immunopathology Laboratory, Department of Pathology, Karolinska Institute/Hospital, Stockholm, Sweden.
Abstract:
Polyomavirus-infected oligodendrocytes and in some instances virus-carrying macrophages were demonstrated within the cytoplasm of astrocytes by double immunostaining of brain lesions in a case of PML following bone marrow transplantation. The infected oligodendrocytes and CD68+ cells were usually partially or completely invested by the cytoplasm of reactive and infected or noninfected giant pleomorphic astrocytes. By electron microscopy (EM), internalized infected oligodendrocytes were shown to release polyomavirus particles possibly infectious to the astrocytes. These observations seem to indicate that astrocytes in PML can become infected by direct contact with internalized infected oligodendrocytes and possibly also by virus-loaded macrophages. Correspondingly, astrocyte/oligodendrocyte/macrophage cell-to-cell interactions appear to play an important role in the pathogenesis of PML lesions.
Insights
In progressive multifocal leukoencephalopathy (PML), astrocytes may become infected by direct contact with polyomavirus-infected oligodendrocytes or macrophages. Cell-to-cell interactions are crucial in PML lesion development.
Area of Science:
- Neurovirology
- Cell Biology
- Immunology
Background:
- Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by JC virus reactivation.
- The precise mechanisms of astrocyte involvement and infection in PML pathogenesis remain incompletely understood.
- Bone marrow transplantation is a known risk factor for PML development.
Observation:
- Polyomavirus-infected oligodendrocytes and virus-carrying macrophages were observed within astrocytes in PML brain lesions.
- Infected oligodendrocytes and CD68+ cells were often enveloped by reactive astrocyte cytoplasm.
- Electron microscopy revealed infected oligodendrocytes releasing polyomavirus particles within astrocytes.
Findings:
- Astrocytes can become infected by polyomavirus through direct contact with internalized infected oligodendrocytes.
- Virus-loaded macrophages may also contribute to astrocyte infection in PML.
- Astrocyte, oligodendrocyte, and macrophage cell-to-cell interactions are implicated in PML pathogenesis.
Implications:
- These findings highlight novel pathways for astrocyte infection in PML.
- Understanding these cell interactions could lead to targeted therapeutic strategies for PML.
- This study provides insights into the complex interplay of glial cells in viral encephalitis.