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Updated: May 20, 2025
Intracerebroventricular and Intravascular Injection of Viral Particles and Fluorescent Microbeads into the Neonatal Brain
Published on: July 24, 2016
The microvascular endothelium of the blood-brain barrier is highly restrictive to JC Polyomavirus neuroinvasion
Avraham S Lukacher1, Bethany A O'Hara1, Wenqing Yuan1
1Department of Cell Biology, Biochemistry, and Molecular Biology, Brown University, Providence, Rhode Island, USA.
Abstract:
JC Polyomavirus is the causative agent of progressive multifocal leukoencephalopathy (PML), an often-fatal demyelinating disease. Unfortunately, a diagnosis of PML occurs only after patients have suffered irreversible neuropathologies. The first step in the initiation of PML is viral entry to the brain, but the route and mechanisms responsible for neuroinvasion have not been well established. To gain a better understanding of this, we asked whether purified virus or virus associated with extracellular vesicles (EVs) could penetrate two different cell culture models of the blood-brain barrier. In one model, we used the hCMEC/D3 brain endothelial cell line, and in the other, we used pluripotent stem cells induced to a brain endothelial cell phenotype (iPSC-EC). We found that neither cell type was permissive to viral infection, but the virus bound and was internalized by both in a sialic acid-dependent manner. Despite virus internalization into these cells, very few virions or virus-associated extracellular vesicles (virus-EVs) penetrated the barriers. The small amount of virus or virus-EVs that did pass through either barrier was sufficient to establish infection in human glial cells. Our findings demonstrate that limited amounts of infectious virions and virus-associated EVs can traverse the brain microvascular endothelium and establish infection.IMPORTANCEThe human polyomavirus, JC Polyomavirus (JCPyV), causes a rapidly progressing demyelinating disease in immunocompromised or immunomodulated patients. Demyelinating lesions are often seen surrounding blood vessels in the brain. In this paper, we used two models to recapitulate a minimal blood-brain barrier and found that both were highly restrictive of virus penetration. A small amount of virus succeeded in crossing both barriers and was sufficient to establish infection of human glia. These data have direct implications for mechanisms used by JCPyV to invade the CNS and cause neurological disease.
Insights
JC Polyomavirus (JCPyV) can invade the central nervous system (CNS) by crossing the blood-brain barrier. Even small amounts of JCPyV, including those within extracellular vesicles, are sufficient to initiate infection in glial cells.
Area of Science:
- Neurovirology
- Cellular Biology
- Infectious Diseases
Background:
- JC Polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease.
- Neuroinvasion mechanisms of JCPyV remain poorly understood, hindering early diagnosis and treatment.
- PML diagnosis often occurs after irreversible neuropathology, emphasizing the need to study viral entry into the brain.
Purpose of the Study:
- To investigate the ability of JCPyV, alone or within extracellular vesicles (EVs), to penetrate models of the blood-brain barrier (BBB).
- To determine the efficiency and mechanisms of JCPyV neuroinvasion across the BBB.
Main Methods:
- Utilized two in vitro blood-brain barrier models: hCMEC/D3 brain endothelial cells and induced pluripotent stem cell-derived endothelial cells (iPSC-ECs).
- Assessed JCPyV binding, internalization, and penetration through these BBB models, both as purified virus and associated with EVs.
- Quantified the infectivity of JCPyV that successfully traversed the BBB models using human glial cells.
Main Results:
- Neither BBB model was permissive to JCPyV infection, but both efficiently bound and internalized the virus in a sialic acid-dependent manner.
- Limited quantities of JCPyV virions and virus-associated EVs penetrated the endothelial barriers.
- The small amount of virus that crossed the BBB was sufficient to establish infection in human glial cells.
Conclusions:
- JCPyV can traverse the brain microvascular endothelium, suggesting a viable route for CNS invasion.
- Virus-associated EVs may play a role in JCPyV neuroinvasion.
- These findings provide critical insights into the mechanisms of JCPyV entry into the CNS, potentially informing future therapeutic strategies for PML.
