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Updated: Sep 29, 2025
Isolation, Transfection, and Culture of Primary Human Monocytes
Published on: December 16, 2019
Epigenetic Landscape of HIV-1 Infection in Primary Human Macrophage
Fang Lu1, Urvi Zankharia2, Olga Vladimirova1
1The Wistar Institute, Philadelphia, Pennsylvania, USA.
Abstract:
Human immunodeficiency virus (HIV)-infected macrophages are long-lived cells that sustain persistent virus expression, which is both a barrier to viral eradication and contributor to neurological complications in patients despite antiretroviral therapy (ART). To better understand the regulation of HIV-1 in macrophages, we compared HIV-infected primary human monocyte-derived macrophages (MDM) to acutely infected primary CD4 T cells and Jurkat cells latently infected with HIV (JLAT 8.4). HIV genomes in MDM were actively transcribed despite enrichment with heterochromatin-associated H3K9me3 across the complete HIV genome in combination with elevated activation marks of H3K9ac and H3K27ac at the long terminal repeat (LTR). Macrophage patterns contrasted with JLAT cells, which showed conventional bivalent H3K4me3/H3K27me3, and acutely infected CD4 T cells, which showed an intermediate epigenotype. 5'-Methylcytosine (5mC) was enriched across the HIV genome in latently infected JLAT cells, while 5'-hydroxymethylcytosine (5hmC) was enriched in CD4 cells and MDMs. HIV infection induced multinucleation of MDMs along with DNA damage-associated p53 phosphorylation, as well as loss of TET2 and the nuclear redistribution of 5-hydoxymethylation. Taken together, our findings suggest that HIV induces a unique macrophage nuclear and transcriptional profile, and viral genomes are maintained in a noncanonical bivalent epigenetic state. IMPORTANCE Macrophages serve as a reservoir for long-term persistence and chronic production of HIV. We found an atypical epigenetic control of HIV in macrophages marked by heterochromatic H3K9me3 despite active viral transcription. HIV infection induced changes in macrophage nuclear morphology and epigenetic regulatory factors. These findings may identify new mechanisms to control chronic HIV expression in infected macrophages.
Insights
Human immunodeficiency virus (HIV) persists in macrophages, a reservoir for chronic viral production. Despite active transcription, HIV DNA in macrophages exhibits atypical epigenetic silencing, offering potential new therapeutic targets.
Area of Science:
- Virology
- Immunology
- Epigenetics
Background:
- Macrophages are long-lived cells that sustain persistent human immunodeficiency virus (HIV) expression, contributing to viral reservoirs and neurological issues.
- Understanding HIV regulation in macrophages is crucial for viral eradication strategies and managing treatment-resistant infections.
- Antiretroviral therapy (ART) is often insufficient to eliminate HIV reservoirs in macrophages.
Purpose of the Study:
- To compare the epigenetic regulation of HIV-1 in primary human monocyte-derived macrophages (MDMs) with acutely infected CD4 T cells and latently infected Jurkat cells (JLAT).
- To investigate the unique transcriptional and nuclear profile of HIV-infected macrophages.
- To identify novel mechanisms for controlling chronic HIV expression in macrophages.
Main Methods:
- Comparative analysis of HIV-infected primary human monocyte-derived macrophages (MDMs), acutely infected CD4 T cells, and latently infected Jurkat cells (JLAT 8.4).
- Chromatin immunoprecipitation (ChIP) to assess histone modifications (H3K9me3, H3K9ac, H3K27ac, H3K4me3, H3K27me3) across the HIV genome.
- Analysis of DNA methylation patterns (5mC, 5hmC) and associated factors (TET2), and assessment of cellular changes like multinucleation and p53 phosphorylation.
Main Results:
- HIV genomes in MDMs showed active transcription despite heterochromatin (H3K9me3) enrichment and active marks (H3K9ac, H3K27ac) at the LTR, contrasting with JLAT cells (bivalent H3K4me3/H3K27me3) and CD4 T cells (intermediate epigenotype).
- 5'-hydroxymethylcytosine (5hmC) was enriched in CD4 cells and MDMs, while 5'-methylcytosine (5mC) was enriched in JLAT cells.
- HIV infection induced MDM multinucleation, DNA damage (p53 phosphorylation), TET2 loss, and altered nuclear 5-hydroxymethylation patterns.
Conclusions:
- HIV establishes a unique nuclear and transcriptional profile in macrophages, maintaining viral genomes in a noncanonical bivalent epigenetic state.
- Atypical epigenetic control, characterized by heterochromatic H3K9me3 despite active transcription, marks HIV in macrophages.
- HIV-induced changes in macrophage nuclear morphology and epigenetic factors suggest novel targets for controlling chronic HIV expression.
