Related Experiment Video
Updated: Sep 5, 2025
12:03
Evaluation of the Efficacy And Toxicity of RNAs Targeting HIV-1 Production for Use in Gene or Drug Therapy
Published on: September 5, 2016
8.0K
Two lymphoid cell lines potently silence unintegrated HIV-1 DNAs
Franziska K Geis1,2,3, Demetra P Kelenis1,2, Stephen P Goff4,5,6
1Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY, USA.
Retrovirology
|July 9, 2022
Summary
Mammalian cells silence viral DNA, but K562 cells show extreme efficiency in silencing unintegrated HIV-1 DNA. This distinct mechanism involves specific histone modifications and resistance to HDAC inhibitors, unlike HeLa cells.
Area of Science:
- Molecular Biology
- Virology
- Cell Biology
Background:
- Mammalian cells possess defense mechanisms against viral infections.
- Transcriptional silencing of viral DNA, including unintegrated retroviral DNA, is a key defense strategy.
- Cellular differences in silencing efficiency are not fully understood.
Purpose of the Study:
- To investigate the efficiency and mechanism of viral DNA silencing in different mammalian cell lines.
- To compare the silencing phenotype of K562 and Jurkat cells against HIV-1 DNA with HeLa cells.
- To elucidate the role of histone modifications and HDAC inhibitors in viral DNA silencing.
Main Methods:
- Infection of K562, Jurkat, and HeLa cells with non-integrating HIV-1 vectors.
- Quantification of viral gene expression using fluorescence reporters.
- Analysis of histone modifications (H3K9 trimethylation, H3 acetylation, H3K27 trimethylation) on viral DNA.
- Treatment with histone deacetylase (HDAC) inhibitor trichostatin A.
Main Results:
- K562 and Jurkat cells exhibited significantly higher silencing of unintegrated HIV-1 DNA compared to HeLa cells.
- K562 cells displayed an extreme silencing phenotype, with reduced reporter gene expression despite equal or higher viral DNA levels.
- Silencing in K562 cells was associated with high H3K9 trimethylation, low H3 acetylation, and low H3K27 trimethylation on viral DNA.
- Trichostatin A treatment only partially relieved silencing in K562 cells, contrasting with HeLa cells.
Conclusions:
- The capacity for silencing viral DNA varies significantly between different cell lines.
- K562 cells employ a distinct and potent mechanism for silencing unintegrated HIV-1 DNA, involving specific epigenetic marks.
- The differential response to HDAC inhibitors suggests mechanistic differences in viral DNA silencing pathways across cell types.
Related Concept Videos
01:29Viruses with RNA Genomes
107
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
107
01:26Size and Structure of Viral Genomes
129
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
129
03:18Non-LTR Retrotransposons
11.8K
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
11.8K