The mTOR Complex Controls HIV Latency.

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Persistent latent HIV-1 reservoirs in CD4 T lymphocytes are a major obstacle to eradicating HIV, even with antiretroviral therapy.
• Understanding the cellular mechanisms governing HIV latency is crucial for developing effective cure strategies.

Purpose of the Study:

• To identify cellular complexes that regulate the persistence of latent HIV genomes.
• To investigate the role of the identified complexes in controlling HIV transcription and latency reversal.

Main Methods:

• A genome-wide screen using a pooled ultracomplex shRNA library was performed.
• An in vitro system modeling HIV latency was utilized to identify modulators.
• Experiments involved knockdown of mTOR complex subunits and pharmacological inhibition of mTOR activity.
• HIV transcription levels were assessed in various HIV-1 latency models and patient-derived cells.

Main Results:

• The mechanistic target of rapamycin (mTOR) complex was identified as a key regulator of HIV latency.
• Inhibition of mTOR complex subunits or activity significantly suppressed the reversal of HIV latency.
• mTOR inhibitors reduced HIV transcription through both Tat-dependent and Tat-independent pathways.
• Inhibition of mTOR signaling led to decreased phosphorylation of CDK9, a critical cofactor for HIV transcription.

Conclusions:

• The mTOR signaling pathway plays a significant role in controlling HIV latency.
• Targeting the mTOR complex presents a promising therapeutic avenue for HIV eradication strategies.
• Further research into mTOR inhibitors could lead to novel treatments for latent HIV infection.