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Published on: September 27, 2012
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Molecular components of the circadian clock regulate HIV-1 replication
Helene Borrmann1, Görkem Ulkar1, Anna E Kliszczak1
1Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
Iscience
|August 3, 2023
Summary
The study reveals that the body's internal clock, or circadian rhythm, influences human immunodeficiency virus 1 (HIV-1) replication. This discovery may lead to new time-based therapies for HIV-1 infection.
Area of Science:
- Virology
- Chronobiology
- Molecular Biology
Background:
- Human immunodeficiency virus 1 (HIV-1) presents a significant global health challenge with no current cure or vaccine.
- Circadian rhythms, the body's internal daily cycles, are crucial for coordinating responses to environmental changes and pathogens.
- Diurnal variations in peripheral HIV-1 viral loads are observed, but the mechanisms driving this rhythmicity are not understood.
Purpose of the Study:
- To investigate the role of the cell-intrinsic circadian clock in regulating HIV-1 replication.
- To elucidate the molecular mechanisms underlying the time-of-day variations in HIV-1 viral loads.
Main Methods:
- Utilized circadian-synchronized systems to study HIV-1 replication.
- Employed gene silencing techniques to investigate the role of the circadian activator Bmal1.
- Performed chromatin immunoprecipitation assays to detect BMAL1 binding to the HIV-1 promoter.
- Analyzed the binding of nuclear receptors REV-ERB and ROR to the HIV-long terminal repeat.
- Conducted bioinformatic analyses to identify circadian-regulated host factors.
Main Results:
- Demonstrated that the cell-intrinsic clock regulates rhythmic HIV-1 replication.
- Showed that silencing Bmal1 abolished the rhythmic replication of HIV-1.
- Confirmed BMAL1 binding to the HIV-1 promoter.
- Revealed differential binding of REV-ERB and ROR to the HIV-long terminal repeat at various circadian times.
- Identified circadian regulation of host factors involved in HIV-1 replication.
Conclusions:
- The circadian clock plays a significant role in regulating HIV-1 replication.
- BMAL1 and its associated nuclear receptors (REV-ERB, ROR) are key components in the time-of-day regulation of HIV-1 transcription.
- Circadian regulation of host factors provides an additional layer of control over rhythmic viral replication.
- Understanding these circadian mechanisms can pave the way for novel, time-based therapeutic strategies against HIV-1.
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