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Biology subjects

Huck, W. T. S.

Publications and source records attributed to Huck, W. T. S..

6 recordsLinked to original sources

Quantifying the deformability of malaria-infected red blood cells using deep learning trained on synthetic cells

Several haematologic diseases, including malaria, diabetes, and sickle cell anaemia, result in a reduced red blood cell deformability. This deformability can be measured using a microfluidic device with channels of varying width. Nevertheless, it is challenging to algorithmically recognise large numbers of red blood cells and quantify their deformability from image data. Deep learning has become the method of choice to handle noisy and complex image data. However, it requires a significant amount of labelled data to train the neural networks. By creating images of cells and mimicking noise and plasticity in those images, we generate synthetic data to train a network to detect and segment red blood cells from video-recordings, without the need for manually annotated labels. Using this new method, we uncover significant differences between the deformability of RBCs infected with different strains of Plasmodium falciparum, providing clues to the variation in virulence of these strains.

microbiology↗

Integrated single-cell (phospho-)protein and RNA detection uncovers phenotypic characteristics of human antibody secreting cells.

Antibody-secreting cells (ASCs) secrete IgM, IgA, or IgG antibodies and are key components of humoral immunity; however, little is known about unique characteristics of the Ig-classes due to limited availability of material and challenges to quantify many intracellular molecular modalities at a single-cell resolution. We combined a method to in vitro differentiate peripheral B-cells into ASCs with integrated multi-omic single-cell sequencing technologies to quantify subclass-specific hallmark surface markers, transcriptional profiles and signaling transduction pathway components. Our approach detected differential expression of plasmablast and plasma cell markers, homing receptors and IL-2, IL-6, JAK/STAT and mTOR signaling activity across Ig-subclasses. Taken together, our integrated multi-omics approach allowed high-resolution phenotypic characterization of single cells in a complex sample of in vitro differentiated human ASCs. Our strategy is expected to further our understanding of human ASCs in healthy and diseased samples and provide a valuable tool to identify novel biomarkers and potential drug targets. TeaserIntegrated single-cell analysis allows tri-modal phenotypic analysis of in-vitro generated human antibody-secreting cells.

immunology↗

Cell-Free Characterization of Coherent Feed-Forward Loop-Based Synthetic Genetic Circuit

Regulatory pathways inside living cells employ feed-forward architectures to fulfill essential signal processing functions that aide in the interpretation of various types of inputs through noise-filtering, fold-change detection and adaptation. Although it has been demonstrated computationally that a coherent feed-forward loop (CFFL) can function as noise filter, a property essential to decoding complex temporal signals, this motif has not been extensively characterized experimentally or integrated into larger networks. Here we use post-transcriptional regulation to implement and characterize a synthetic CFFL in an Escherichia coli cell-free transcription-translation system and build larger composite feed-forward architectures. We employ microfluidic flow reactors to probe the response of the CFFL circuit using both persistent and short, noise-like inputs and analyze the influence of different circuit components on the steady-state and dynamics of the output. We demonstrate that our synthetic CFFL implementation can reliably repress background activity compared to a reference circuit, but displays low potential as a temporal filter, and validate these findings using a computational model. Our results offer practical insight into the putative noise-filtering behavior of CFFLs and show that this motif can be used to mitigate leakage and increase the fold-change of the output of synthetic genetic circuits.

synthetic biology↗

Single-cell intracellular epitope and transcript detection revealing signal transduction dynamics

Current high-throughput single-cell multi-omics methods cannot concurrently map changes in (phospho)protein levels and the associated gene expression profiles. We present QuRIE-seq (Quantification of RNA and Intracellular Epitopes by sequencing) and use multi-factor omics analysis (MOFA+) to map signal transduction over multiple timescales. We demonstrate that QuRIE-seq can trace the activation of the B-cell receptor pathway at the minute and hour time-scale and provide insight into the mechanism of action of an inhibitory drug, Ibrutinib.

molecular biology↗

Energy Expenditure during Cell Spreading Induces AMPK Activation and Regulates the Mechanoresponse of Stem Cells

Cells respond to the mechanical properties of the extracellular matrix (ECM) through formation of focal adhesions (FAs), re-organization of the actin cytoskeleton and adjustment of cell contractility. These are energy-demanding processes, but a potential causality between mechanical cues (matrix stiffness) and cellular (energy) metabolism remains largely unexplored. Here, we culture human mesenchymal stem cells (hMSCs) on stiff (20 kPa) or soft (1 kPa) substrate and demonstrate that cytoskeletal reorganization and FA formation spreading on stiff substrates lead to a drop in intracellular ATP levels, correlates with the activation of AMP-activated protein kinase (AMPK). The resulting increase in ATP levels further facilitates cell spreading and reinforces cell tension of the steady state, and coincides with nuclear localization of YAP/TAZ and Runx2. While on soft substrates (1 kPa), lowered ATP levels limit these cellular mechanoresponses. Furthermore, genetic ablation of AMPK lowered cellular ATP levels on stiff substrate and strongly reduced responses to substrate stiffness. Together, these findings reveal a hitherto unidentified relationship between energy expenditure and the cellular mechanoresponse, and point to AMPK as a key mediator of stem cell fate in response to ECM mechanics.

cell biology↗

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↗