Biology subjects

Pohl, T.

Publications and source records attributed to Pohl, T..

3 recordsLinked to original sources

bioRxiv2026

Balancing spatial resolution and proteome depth in LC-MS based spatialproteomics

Spatial proteomics aims to resolve protein composition within intact tissues, yet extraction-based liquid chromatography-mass spectrometry (LC-MS) workflows face an inherent trade-off: smaller sampling units increase spatial specificity, whereas larger sampling units provide greater proteome depth and robustness. As analytical sensitivity improves, sampling-unit size therefore becomes a key experimental design parameter. Current extraction-based LC-MS workflows typically rely on laser capture microdissection (LCM), where sample recovery and scalability can become limiting at low input. Spatially resolved laser-activated cell sorting (SLACS) offers an alternative tissue-isolation strategy based on single-pulse near-infrared laser activation. Here, we use SLACS to systematically examine the resolution-sensitivity trade-off across sampling units ranging from single-cell-equivalent to larger low-input tissue regions. Few-cell sampling retained substantial proteomic information relative to larger regions while increasing spatial specificity. Applied to the mouse somatosensory cortex, SLACS generated deep, layer-resolved proteomic profiles from regions corresponding to approximately 60 cells and preserved major layer-specific molecular patterns at inputs as low as approximately 6 cells. These results highlight sampling-unit size as an important experimental design parameter in extraction-based spatial proteomics and support few-cell sampling as a practical compromise between spatial specificity, proteome depth and robustness.

biochemistry↗

bioRxiv2026

Germline-encoded V(D)J gene usage does not impose strict constraints on the epitope-specificity of T cell receptors

The theoretical diversity of T cell receptors (TCRs), generated through V(D)J recombination, is enormous, yet the diversity of TCRs capable of recognizing the same epitope remains unknown. Defining this TCR solution space is essential for uncovering basic principles that govern TCR specificity. Using single-cell RNA and TCR sequencing, we generated ultra-deep (more than 4000 unique TCRs per epitope) epitope-specific TCR libraries derived from 560 immunized C57BL/6 mice, identifying over 27,000 unique epitope-reactive TCRs across three distinct CD8+ T cell epitopes presented by two major histocompatibility complex (MHC) class I alleles. Saturation analyses indicated that the solution space for all studied epitopes comprises many tens of thousands of unique TCRs. Despite highly skewed and peptide-dependent VJ-usage patterns, nearly the entire set of functional germline V/ and J/ segments was detected at least once within each epitope-specific repertoire. Therefore, diversity of epitope-specific TCRs is not limited by distinct germline combinations but rather can emerge from a near-to-complete combinatorial space of - and -chain, V and J segments paired with compatible CDR3 sequences.

immunology↗

bioRxiv2023

Touch sensation requires the mechanically-gated ion channel Elkin1.

The slightest touch to the skin initiates tactile perception that is almost immediate1. The extraordinary speed of touch perception is enabled by mechanically-activated ion channels, the opening of which excites the endings of sensory neurons innervating the skin to initiate sensation. Here we identify a new mechanically-activated ion channel, Elkin12, that, when ablated in mice, leads to a profound behavioural touch insensitivity. Touch insensitivity in Elkin1-/- mice was caused by a loss of mechanically-activated currents (MA-currents) in around half of all sensory neurons that are activated by light touch (low threshold mechanoreceptors, LTMRs). Reintroduction of Elkin1 into sensory neurons from Elkin1-/- mice acutely restored MA-currents. Piezo23-6 is an established mechanosensitive ion channel required for touch sensation. In mice genetic ablation of Piezo2 renders many, but not all, LTMRs insensitive to mechanical force4,5,7. Here we show that Elkin1 underpins PIEZO2-independent touch sensation. Additionally, we find that Elkin1 is present in many nociceptive sensory neurons which detect potentially damaging and painful mechanical force. These nociceptors depend on Elkin1 for effectively communicating information on sustained noxious mechanical forces. We further identified molecular and functional interactions between the known mechanotransduction protein Stoml38,9 and Elkin1 ion channels. Our data identify Elkin1 as a novel core component of touch transduction in mammals. The specific sensory deficits exhibited by Elkin1-/- mice make Elkin1 a highly desirable target that could be harnessed to treat somatic sensory disorders including pain.

neuroscience↗