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Biology subjects

Muraro, M. J.

Publications and source records attributed to Muraro, M. J..

7 recordsLinked to original sources

Persistent Microglial HIV Infection Drives Neuroinflammation Despite Viral Suppression: Insights from Rapid Postmortem Brain Biopsies

Despite suppressive antiretroviral therapy (ART), HIV persists in the central nervous system (CNS) and contributes to HIV-associated neurocognitive disorder (HAND), but cell type-specific effects remain poorly defined. Using fluorescence-activated nuclei sorting of postmortem brain tissue of aviremic and viremic deceased people with HIV (DPWH) and HIV-negative individuals, we quantified the size of the HIV CNS reservoir and transcriptional alterations. Microglia were identified as the dominant CNS reservoir, harboring 103-10 HIV DNA copies per million cells by ddPCR-LTR assay in both aviremic and viremic DPWH. Bulk RNA-sequencing revealed immune pathway upregulation specifically in microglia, and downregulation of synaptic and homeostatic pathways across cell-types in viremic compared to aviremic individuals. ART partially mitigated microglial transcriptional dysregulation, but transcriptional profiles did not restore profiles to HIV-negative levels. Notably, persistent microglial infection was associated with transcriptional changes in other cell-types, underscoring microglia as a key therapeutical target for CNS-directed HIV cure strategies.

neuroscience↗

SARS-CoV-2 Omicron efficiently infects human airway, but not alveolar epithelium

In late 2021, the highly mutated SARS-CoV-2 Omicron variant emerged, raising concerns about its potential extensive immune evasion, increased transmissibility and pathogenicity. Here, we used organoids of the human airways and alveoli to investigate Omicrons fitness and replicative potential in comparison with earlier SARS-CoV-2 variants. We report that Omicron replicates more rapidly in the airways and has an increased fitness compared to the early 614G variant and Delta. In contrast, Omicron did not replicate productively in human alveolar type 2 cells. Mechanistically, we show that Omicron does not efficiently use TMPRSS2 for entry or spread through cell-cell fusion. Altogether, our data show that Omicron has an altered tropism and protease usage, potentially explaining its higher transmissibility and decreased pathogenicity.

microbiology↗

Human organoid systems reveal in vitro correlates of fitness for SARS-CoV-2 B.1.1.7

A new phase of the COVID-19 pandemic has started as several SARS-CoV-2 variants are rapidly emerging globally, raising concerns for increased transmissibility. As animal models and traditional in vitro systems may fail to model key aspects of the SARS-CoV-2 replication cycle, representative in vitro systems to assess variants phenotypically are urgently needed. We found that the British variant (clade B.1.1.7), compared to an ancestral SARS-CoV-2 clade B virus, produced higher levels of infectious virus late in infection and had a higher replicative fitness in human airway, alveolar and intestinal organoid models. Our findings unveil human organoids as powerful tools to phenotype viral variants and suggest extended shedding as a correlate of fitness for SARS-CoV-2. One-Sentence SummaryBritish SARS-CoV-2 variant (clade B.1.1.7) infects organoids for extended time and has a higher fitness in vitro.

microbiology↗

Human Prostate Cancer-Associated Macrophage Subtypes with Prognostic Potential Revealed by Single-cell Transcriptomics

Macrophages in the tumor microenvironment are causally linked with prostate cancer development and progression, yet little is known about their composition in neoplastic human tissue. By performing single cell transcriptomic analysis of human prostate cancer resident macrophages, three distinct populations were identified in the diseased prostate. Unexpectedly, macrophages isolated from the tumor-adjacent site of the prostatectomy specimen were identical to those from the tumorous site. Markers associated with canonical M1 and M2 macrophage phenotypes were identifiable, however these were not the main factors defining unique subtypes. The genes selectively associated with each macrophage cluster were used to develop a gene signature which was highly associated with both recurrence-free and metastasis-free survival. These results highlight the relevance of tissue-specific macrophage subtypes in the tumour microenvironment for prostate cancer progression and demonstrates the utility of profiling single-cell transcriptomics in human tumor samples as a strategy to design gene classifiers for patient prognostication.

immunology↗

Cell type purification by single-cell transcriptome-trained sorting

Traditional cell type enrichment using fluorescence activated cell sorting (FACS) relies on methods that specifically label the cell type of interest. Here we propose GateID, a computational method that combines single-cell transcriptomics for unbiased cell type identification with FACS index sorting to purify cell types of choice. We validate GateID by purifying various cell types from the zebrafish kidney marrow and the human pancreas without resorting to specific antibodies or transgenes.

bioinformatics↗

Combined quantification of intracellular (phospho-)proteins and transcriptomics from fixed single cells.

Environmental stimuli often lead to heterogeneous cellular responses and transcriptional output. We developed single-cell RNA and Immunodetection (RAID) to allow combined analysis the transcriptome and intracellular (phospho-)proteins from fixed single cells. RAID successfully recapitulated differentiation-state changes at the protein and mRNA level in human keratinocytes. Furthermore, we show that differentiated keratinocytes that retain high phosphorylated FAK levels, a feature associated with stem cells, also express a selection of stem cell associated transcripts. Our data demonstrates that RAID allows investigation of heterogenenous cellular responses to environmental signals at the mRNA and phospho-proteome level.

genomics↗

Sharq, a versatile preprocessing and QC pipeline for Single Cell RNA-seq

Despite the meteoric rise of single cell RNA-seq, only a few preprocessing pipelines exist that are able to perform all steps from the original fastq files to a gene expression table ready for further analysis. Here we present Sharq, a versatile preprocessing pipeline designed to work with plate-based 3-end protocols that include Unique Molecular Identifiers (UMIs). Sharq performs stringent step-wise trimming of reads, assigns them to features according to a flexible hierarchical model, and uses the barcode and UMI information to avoid amplification biases and produce gene expression tables. Additionally, Sharq provides an extensive plate diagnostics report for quality control and troubleshooting, including that of spatial artefacts. The diagnostics report includes measures of the quality of the individual plate wells as well as a robust assessment which of them contain material from live cells. Collectively, the innovative approaches presented here provide a valuable tool for processing and quality control of single cell RNA-seq data.

bioinformatics↗