Dataset Information

SAMHD1 enhances nucleoside-analogue efficacy against HIV-1 in myeloid cells.

ABSTRACT: SAMHD1 is an intracellular enzyme that specifically degrades deoxynucleoside triphosphates into component nucleoside and inorganic triphosphate. In myeloid-derived dendritic cells and macrophages as well as resting T-cells, SAMHD1 blocks HIV-1 infection through this dNTP triphosphohydrolase activity by reducing the cellular dNTP pool to a level that cannot support productive reverse transcription. We now show that, in addition to this direct effect on virus replication, manipulating cellular SAMHD1 activity can significantly enhance or decrease the anti-HIV-1 efficacy of nucleotide analogue reverse transcription inhibitors presumably as a result of modulating dNTP pools that compete for recruitment by viral polymerases. Further, a variety of other nucleotide-based analogues, not normally considered antiretrovirals, such as the anti-herpes drugs Aciclovir and Ganciclovir and the anti-cancer drug Clofarabine are now revealed as potent anti-HIV-1 agents, under conditions of low dNTPs. This in turn suggests novel uses for nucleotide analogues to inhibit HIV-1 in differentiated cells low in dNTPs.

SUBMITTER: Ordonez P

PROVIDER: S-EPMC5318888 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

SAMHD1 enhances nucleoside-analogue efficacy against HIV-1 in myeloid cells.

Ordonez Paula P Kunzelmann Simone S Groom Harriet C T HC Yap Melvyn W MW Weising Simon S Meier Chris C Bishop Kate N KN Taylor Ian A IA Stoye Jonathan P JP

Scientific reports 20170221

SAMHD1 is an intracellular enzyme that specifically degrades deoxynucleoside triphosphates into component nucleoside and inorganic triphosphate. In myeloid-derived dendritic cells and macrophages as well as resting T-cells, SAMHD1 blocks HIV-1 infection through this dNTP triphosphohydrolase activity by reducing the cellular dNTP pool to a level that cannot support productive reverse transcription. We now show that, in addition to this direct effect on virus replication, manipulating cellular SAM ...[more]

PMID: 28220857

Similar Datasets

Project description:BackgroundSAMHD1 mediates resistance to anti-cancer nucleoside analogues, including cytarabine, decitabine, and nelarabine that are commonly used for the treatment of leukaemia, through cleavage of their triphosphorylated forms. Hence, SAMHD1 inhibitors are promising candidates for the sensitisation of leukaemia cells to nucleoside analogue-based therapy. Here, we investigated the effects of the cytosine analogue CNDAC, which has been proposed to be a SAMHD1 inhibitor, in the context of SAMHD1.MethodsCNDAC was tested in 13 acute myeloid leukaemia (AML) cell lines, in 26 acute lymphoblastic leukaemia (ALL) cell lines, ten AML sublines adapted to various antileukaemic drugs, 24 single cell-derived clonal AML sublines, and primary leukaemic blasts from 24 AML patients. Moreover, 24 CNDAC-resistant sublines of the AML cell lines HL-60 and PL-21 were established. The SAMHD1 gene was disrupted using CRISPR/Cas9 and SAMHD1 depleted using RNAi, and the viral Vpx protein. Forced DCK expression was achieved by lentiviral transduction. SAMHD1 promoter methylation was determined by PCR after treatment of genomic DNA with the methylation-sensitive HpaII endonuclease. Nucleoside (analogue) triphosphate levels were determined by LC-MS/MS. CNDAC interaction with SAMHD1 was analysed by an enzymatic assay and by crystallisation.ResultsAlthough the cytosine analogue CNDAC was anticipated to inhibit SAMHD1, SAMHD1 mediated intrinsic CNDAC resistance in leukaemia cells. Accordingly, SAMHD1 depletion increased CNDAC triphosphate (CNDAC-TP) levels and CNDAC toxicity. Enzymatic assays and crystallisation studies confirmed CNDAC-TP to be a SAMHD1 substrate. In 24 CNDAC-adapted acute myeloid leukaemia (AML) sublines, resistance was driven by DCK (catalyses initial nucleoside phosphorylation) loss. CNDAC-adapted sublines displayed cross-resistance only to other DCK substrates (e.g. cytarabine, decitabine). Cell lines adapted to drugs not affected by DCK or SAMHD1 remained CNDAC sensitive. In cytarabine-adapted AML cells, increased SAMHD1 and reduced DCK levels contributed to cytarabine and CNDAC resistance.ConclusionIntrinsic and acquired resistance to CNDAC and related nucleoside analogues are driven by different mechanisms. The lack of cross-resistance between SAMHD1/ DCK substrates and non-substrates provides scope for next-line therapies after treatment failure.

Project description:Analogues and derivatives of natural nucleosides/nucleotides are considered among the most successful bioactive species of drug-like compounds in modern medicinal chemistry, as they are well recognized for their diverse and efficient pharmacological activities in humans, especially as antivirals and antitumors. Coronavirus disease 2019 (COVID-19) is still almost incurable, with its infectious viral microbe, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continuing to wreak devastation around the world. This global crisis pushed all involved scientists, including drug discoverers and clinical researchers, to try to find an effective and broad-spectrum anti-COVID-19 drug. Didanosine (2',3'-dideoxyinosine, DDI) is a synthetic inosine/adenosine/guanosine analogue and highly active antiretroviral therapeutic agent used for the treatment of human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS). This potent reverse-transcriptase inhibitor is characterized by proven strong pharmacological effects against the viral genome, which may successfully take part in the effective treatment of SARS-CoV-2/COVID-19. Additionally, targeting the pivotal SARS-CoV-2 replication enzyme, RNA-dependent RNA polymerase (RdRp), is a very successful tactic to combat COVID-19 irrespective of the SARS-CoV-2 variant type because RdRps are broadly conserved among all SARS-CoV-2 strains. Herein, the current study proved for the first time, using the in vitro antiviral evaluation, that DDI is capable of potently inhibiting the replication of the novel virulent progenies of SARS-CoV-2 with quite tiny in vitro anti-SARS-CoV-2 and anti-RdRp EC50 values of around 3.1 and 0.19 μM, respectively, surpassing remdesivir together with its active metabolite (GS-441524). Thereafter, the in silico computational interpretation of the biological results supported that DDI strongly targets the key pocket of the SARS-CoV-2 RdRp main catalytic active site. The ideal pharmacophoric characteristics of the ligand DDI make it a typical inhibiting agent of SARS-CoV-2 multiplication processes (including high-fidelity proofreading), with its elastic structure open for many kinds of derivatization. In brief, the present results further uphold and propose the repurposing potentials of DDI against the different types of COVID-19 and convincingly motivate us to quickly launch its extensive preclinical/clinical pharmacological evaluations, hoping to combine it in the COVID-19 therapeutic protocols soon.

Dataset Information

SAMHD1 enhances nucleoside-analogue efficacy against HIV-1 in myeloid cells.

Publications

SAMHD1 enhances nucleoside-analogue efficacy against HIV-1 in myeloid cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets