Intron-containing RNA from the HIV-1 provirus activates type I interferon and inflammatory cytokines

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Antiviral therapy suppresses HIV-1 viremia to undetectable levels, preventing AIDS.
• However, HIV-1 establishes latent reservoirs in long-lived CD4+ memory T cells, hindering complete viral eradication.
• The innate immune system's role in detecting persistent HIV-1 infection requires further elucidation.

Purpose of the Study:

• To investigate whether the HIV-1 provirus activates innate immune signaling pathways.
• To identify the specific viral components and mechanisms responsible for this immune activation.
• To explore potential therapeutic strategies targeting HIV-1 RNA metabolism.

Main Methods:

• Isolation of dendritic cells, macrophages, and CD4+ T cells.
• Analysis of innate immune signaling activation in response to HIV-1 proviral expression.
• Investigation of the role of HIV-1 RNA structure, transcription, and post-transcriptional regulation (e.g., Rev/RRE pathway) in immune activation.

Main Results:

• HIV-1 proviral transcription and expression of unspliced, Rev-dependent HIV-1 RNA activate innate immune signaling in immune cells.
• Immune activation is dependent on specific cis-acting sequences within the HIV-1 RNA, not necessarily all viral coding sequences.
• The complex post-transcriptional regulation of HIV-1 RNA is recognized as a danger signal by the innate immune system.

Conclusions:

• The HIV-1 provirus actively engages innate immune signaling, potentially contributing to viral persistence or immune dysregulation.
• Targeting HIV-1 transcription or RNA metabolism represents a promising strategy to enhance current antiviral therapies.
• Understanding HIV-1 RNA as a danger signal opens new avenues for controlling latent viral reservoirs.