Where does HIV hide? A focus on the central nervous system.

Area of Science:

• Neuroscience
• Virology
• Immunology

Background:

• The brain serves as a significant reservoir for human immunodeficiency virus (HIV).
• Understanding HIV's behavior within the central nervous system is crucial for effective treatment and eradication strategies.
• The unique environment of the brain influences viral evolution and pathogenesis.

Purpose of the Study:

• To review existing literature on HIV infection and evolution within the brain.
• To elucidate the nature of the brain's viral reservoir.
• To understand the consequences of HIV's adaptation to the brain environment.

Main Methods:

• Literature review of studies on HIV infection and evolution in the brain.
• Analysis of viral adaptation mechanisms within brain compartments.
• Examination of viral genetic mutations specific to the brain.

Main Results:

• HIV-1 evolves in distinct compartments within the brain, specifically in macrophages/microglia and astrocytes.
• The virus undergoes adaptation, acquiring brain-specific mutations across its genome to infect these resident cells.
• Evidence suggests HIV evolves towards increased neurovirulence within the brain.

Conclusions:

• The brain represents an ideal, immune-privileged reservoir for HIV due to the blood-brain barrier limiting drug access.
• Long-lived cells like macrophages and astrocytes are infected by HIV, with minimal observed cytopathology.
• Strategies for HIV eradication must address the brain reservoir, focusing on maintaining viral latency to prevent adverse outcomes.