Biology subjects

Berkhout, B.

Publications and source records attributed to Berkhout, B..

3 recordsLinked to original sources

bioRxiv2025

Pure CD32+ CD4+ Cells Are Cytotoxic Memory CD4+ T Lymphocytes Highly Enriched for HIV-1 DNA

The elusive viral reservoir is the major obstacle to an HIV-1 cure. Cell surface protein CD32 has been proposed to pinpoint cells with a very high proviral enrichment, potentially providing a tool for selective therapeutic targeting of the reservoir. However, this finding has been challenged by subsequent reports. In order to clarify the nature of CD32 expression on CD4+ T cells, here we designed a purification strategy allowing single-cell analysis using state-of-the-art technologies. The established multilevel sorting strategy allowed to characterize a rare (median 0.06% of CD4+ T cells) but bona fide CD32+ CD4+ T-cell population. In vitro cell stimulation could not lead to CD32 upregulation. Detailed phenotyping revealed that CD32+ T cells reside mostly in the memory T-cell compartment with heightened levels of acute and chronic activation markers. Single-cell RNA sequencing identified that CD32+ CD4+ T cells are mostly highly cytotoxic CD4+ cells. Importantly. in HIV-1 infected donors under suppressive antiretroviral therapy, we found that these cells are highly enriched for HIV-1 provirus, harbor a clear cytotoxic memory T-cell transcriptome, as well as TCR clonal enrichment. These findings indicate that CD32 remains a promising candidate marker of the HIV-1 reservoir and underline the importance of further investigation of this marker during latent infection.

immunology↗

bioRxiv2021

Novel Role of UHRF1 in DNA methylation-mediated repression of latent HIV-1

The multiplicity, heterogeneity and dynamic nature of HIV-1 latency mechanisms are reflected in the current lack of functional cure for HIV-1 and in the various reported ex vivo potencies of latency- reversing agents. Here, we investigated the molecular mechanisms underlying the potency of the DNA methylation inhibitor 5-aza-2-deoxycytidine (5-AzadC) in HIV-1 latency reversal. Doing so, we uncovered specific demethylation CpG signatures induced by 5-AzadC in the HIV-1 promoter. By analyzing the binding modalities to these CpG, we revealed the recruitment of the epigenetic integrator UHRF1 to the HIV-1 promoter. We further demonstrated the role of UHRF1 in DNA methylation- mediated silencing of the latent HIV-1 promoter. As a proof-of-concept to this molecular characterization, we showed that pharmacological downregulation of UHRF1 in ex vivo HIV+ patient cell cultures resulted in potent reactivation of latent HIV-1. Together, we identify UHRF1 as a novel actor in HIV-1 gene silencing and highlight that it constitutes a new molecular target for HIV-1 curative strategies.

microbiology↗

bioRxiv2016

Easy and Accurate Reconstruction of Whole HIV Genomes from Short-Read Sequence Data

Next-generation sequencing has yet to be widely adopted for HIV. The difficulty of accurately reconstructing the consensus sequence of a quasispecies from reads (short fragments of DNA) in the presence of rapid between- and within-host evolution may have presented a barrier. In particular, mapping (aligning) reads to a reference sequence leads to biased loss of information; this bias can distort epidemiological and evolutionary conclusions. De novo assembly avoids this bias by effectively aligning the reads to themselves, producing a set of sequences called contigs. However contigs provide only a partial summary of the reads, misassembly may result in their having an incorrect structure, and no information is available at parts of the genome where contigs could not be assembled. To address these problems we developed the tool shiver to preprocess reads for quality and contamination, then map them to a reference tailored to the sample using corrected contigs supplemented with existing reference sequences. Run with two commands per sample, it can easily be used for large heterogeneous data sets. We use shiver to reconstruct the consensus sequence and minority variant information from paired-end short-read data produced with the Illumina platform, for 65 existing publicly available samples and 50 new samples. We show the systematic superiority of mapping to shivers constructed reference over mapping the same reads to the standard reference HXB2: an average of 29 bases per sample are called differently, of which 98.5% are supported by higher coverage. We also provide a practical guide to working with imperfect contigs.

bioinformatics↗