How viruses infiltrate the central nervous system.

Area of Science:

• Neuroscience
• Virology
• Immunology

Background:

• The blood-brain barrier (BBB) protects the central nervous system (CNS) and is part of the neurovascular unit.
• Viruses can breach the BBB, leading to CNS invasion and dysfunction.
• BBB dysfunction includes increased permeability, inflammation, and encephalopathy.

Purpose of the Study:

• To review the mechanisms by which viruses cross the blood-brain barrier.
• To summarize the cellular responses of neurons and glial cells to viral infections within the CNS.

Main Methods:

• Literature review of viral entry mechanisms into the brain.
• Compilation of known viruses that infect the CNS.
• Summary of host cell responses to viral neuroinvasion.

Main Results:

• Viruses utilize paracellular, transcellular, or "Trojan horse" pathways to cross the BBB.
• Numerous viruses, including HIV-1, influenza, herpes simplex virus, and arboviruses, can infect the CNS.
• Viral entry triggers inflammatory responses and affects neuronal and glial cell function.

Conclusions:

• Understanding viral BBB traversal is crucial for combating neurotropic infections.
• Viral invasion of the CNS leads to complex interactions between the virus and host cells.
• Further research is needed to elucidate specific viral pathways and host responses.