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Palbociclib, a selective inhibitor of cyclin-dependent kinase4/6, blocks HIV-1 reverse transcription through the control of sterile α motif and HD domain-containing protein-1 (SAMHD1) activity.
- Source :
-
AIDS (London, England) [AIDS] 2014 Sep 24; Vol. 28 (15), pp. 2213-22. - Publication Year :
- 2014
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Abstract
- Background: Sterile α motif and HD domain-containing protein-1 (SAMHD1) inhibits HIV-1 reverse transcription by decreasing the pool of intracellular deoxynucleotides. SAMHD1 is controlled by cyclin-dependent kinase (CDK)-mediated phosphorylation. However, the exact mechanism of SAMHD1 regulation in primary cells is unclear. We explore the effect of palbociclib, a CDK6 inhibitor, in HIV-1 replication.<br />Methods: Human primary monocytes were differentiated into macrophages with monocyte-colony stimulating factor and CD4 T lymphocytes stimulated with phytohaemagglutinin (PHA)/interleukin-2. Cells were treated with palbociclib and then infected with a Green fluorescent protein-expressing HIV-1 or R5 HIV-1 BaL. Viral DNA was measured by quantitative PCR and infection assessed by flow cytometry. Deoxynucleotide triphosphate (dNTP) content was determined using a polymerase-based method.<br />Results: Pan-CDK inhibitors AT7519, roscovitine and purvalanol A reduced SAMHD1 phosphorylation. HIV-1 replication was blocked by AT7519 (66.4 ± 3.8%; n = 4), roscovitine (47.3 ± 3.9%; n = 4) and purvalanol A (55.7 ± 15.7%; n = 4) at subtoxic concentrations. Palbociclib, a potent and selective CDK6 inhibitor, blocked SAMHD1 phosphorylation, intracellular dNTP levels, HIV-1 reverse transcription and HIV-1 replication in primary macrophages and CD4 T lymphocytes. Notably, treatment of macrophages with palbociclib led to reduced CDK2 activation, measured as the phosphorylation of the T-loop at the Thr160. The antiviral effect was lost when SAMHD1 was degraded by Vpx, providing further evidence for a role of SAMHD1 in mediating the antiretroviral effect.<br />Conclusions: Our results indicate that SAMHD1-mediated HIV-1 restriction is controlled by CDK as previously suggested but point to a preferential role for CDK2 and CDK6 as mediators of SAMHD1 activation. Our study provides a new signaling pathway susceptible for the development of new therapeutic approaches against HIV-1 infection.
- Subjects :
- Cells, Cultured
Cyclin-Dependent Kinase 2 metabolism
Cyclin-Dependent Kinase 6 metabolism
DNA, Viral analysis
Humans
Leukocytes, Mononuclear virology
Real-Time Polymerase Chain Reaction
SAM Domain and HD Domain-Containing Protein 1
Anti-HIV Agents metabolism
HIV-1 physiology
Monomeric GTP-Binding Proteins antagonists & inhibitors
Piperazines metabolism
Protein Kinase Inhibitors metabolism
Pyridines metabolism
Reverse Transcription
Subjects
Details
- Language :
- English
- ISSN :
- 1473-5571
- Volume :
- 28
- Issue :
- 15
- Database :
- MEDLINE
- Journal :
- AIDS (London, England)
- Publication Type :
- Academic Journal
- Accession number :
- 25036183
- Full Text :
- https://doi.org/10.1097/QAD.0000000000000399