A recent study, led by the Advanced Molecular Virology Unit (Institut Pasteur) and combining virology, structural biology, and immunology, has uncovered a key mechanism involved in the establishment of an efficient infection and evasion of innate immunity of HIV-1 virus (responsible for AIDS disease) in the organism.

The authors focused their work on HIV-1 condensates, called HIV-1 membraneless organelles (HIV-1-MLOs) which are tiny structures composed of viral genetic material and proteins that form in the nucleus of infected cells.

Key results

Researchers have discovered HIV-1 MLOs exist in vivo and act as a shield, allowing viral DNA to hide from cellular DNA sensors that trigger a pathway of our antiviral immune response when they detect a foreign DNA.

These structures can regulate the temporal and spatial conditions to create the perfect environment for reverse transcription (RNA to DNA conversion), a crucial step for the virus to replicate and spread in the organism.

New perspectives

These discoveries open new perspectives for:

• Enhancing our understanding of how HIV-1 escapes immune detection.
• Developing treatments targeting the formation of HIV-1 MLOs in the early stages of infection.
• Exploring similar mechanisms in other viruses.

Microscopy imaging: a key player

Advanced microscopy techniques were essential in visualizing the formation and function of these structures, including:

• Confocal microscopy (Pasteur PBI platform) – to study host-pathogen interactions in live-cell imaging and visualize the existence of HIV-1-MLOs in vivo.
• Transmission electron microscopy (Electron Microscopy Platform of the University of Tours) and tomography (Pasteur UBI platform) – to reveal ultrastructural details at the molecular level.

France-BioImaging’s Pasteur PBI and UBI platforms (Paris-Centre Node) in collaboration with the Electron Microscopy Platform of the University of Tours provided cutting-edge expertise and equipment, playing a central role in unraveling this viral strategy. By enabling researchers to see what was once invisible, imaging technologies continue to be at the heart of discoveries that push the boundaries of infectious disease research!

Read the full article here: https://pubmed.ncbi.nlm.nih.gov/39623137/