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Biology subjects

Beusch, C. M.

Publications and source records attributed to Beusch, C. M..

5 recordsLinked to original sources

A scalable proteogenomic framework for dissecting phospho-signaling pathways in primary immune cells

Signaling networks modulated by post-translational modifications orchestrate cellular responses to external cues. Traditional approaches to study these pathways lack the throughput to systematically capture the causal architecture of these signaling pathways at scale. Here, we present an integrated proteogenomic framework that combines saturating genetic perturbations with high-throughput proteomics to systematically map cytokine-induced signaling in primary human T cells. Supporting this framework is simplePhos, a streamlined, low-input phosphoproteomics workflow that enables scalable, time-resolved analysis without the requirement for specialized equipment or robotics. We extensively validate the simplePhos pipeline by applying inflammatory stimuli, including type I and II interferons, lipopolysaccharide, and Sendai virus to primary T cells and myeloid cells, establishing foundational datasets in these treatment contexts. Ultimately, using type I interferon signaling in genetically modified T cells as a model, we demonstrate that combined application of genetic alterations and proteomic analyses can map key signaling nodes in primary immune cells. This represents a powerful strategy to mechanistically interrogate phospho-signaling networks in human immune cells, with broad applications in translational immunology and therapeutic development.

systems biology↗

Global analysis of protein turnover dynamics in single cells

Even with recent improvements in sample preparation and instrumentation, single-cell proteomics (SCP) analyses mostly measure protein abundances, making the field unidimensional. In this study, we employ a pulsed stable isotope labeling by amino acids in cell culture (SILAC) approach to simultaneously evaluate protein abundance and turnover in single cells (SC-pSILAC). Using state-of-the-art SCP workflow, we demonstrated that two SILAC labels are detectable from [~]4000 proteins in single HeLa cells recapitulating known biology. We investigated drug effects on global and specific protein turnover in single cells and performed a large-scale time-series SC-pSILAC analysis of undirected differentiation of human induced pluripotent stem cells (iPSC) encompassing six sampling times over two months and analyzed >1000 cells. Abundance measurements highlighted cell-specific markers of stem cells and various organ-specific cell types. Protein turnover dynamics highlighted differentiation-specific co-regulation of core members of protein complexes with core histone turnover discriminating dividing and non-dividing cells with potential in stem cell and cancer research. Our study represents the most comprehensive SCP analysis to date, offering new insights into cellular diversity and pioneering functional measurements beyond protein abundance. This method distinguishes SCP from other single-cell omics approaches and enhances its scientific relevance in biological research in a multidimensional manner.

systems biology↗

Longitudinal proteomic analysis of T cell differentiation in vivo reveals dynamic changes of the interactome

CD8 T cell exhaustion impedes immune responses to cancer and chronic infections, and a biochemical understanding of exhaustion is essential to improving immunotherapy. Here, we present the first longitudinal protein abundance and phosphoproteomic analysis of antigen-specific CD8 T cells undergoing differentiation in vivo during acute (LCMV-Armstrong) and chronic (LCMV-Clone 13) infection. Comparing protein abundance across the two infection conditions identified over 180 known and novel exhaustion-associated proteins, including proteins missed by transcriptional analyses. Phosphoproteomic analysis identified >900 differentially regulated phosphosites on >400 proteins, including known inhibitory phosphosites on PD1, PAG1, SHP-1/PTPN6, SLAMF1/CD150. We also calculated phosphosite conservation across mammals, to direct follow-up studies towards sites with likely essential function. Lastly, our analysis uncovers exhaustion-associated kinases with clinical-stage inhibitors, underscoring the translational utility of our dataset to guide immunotherapy development. Together, our datasets define a biochemical atlas of T cell exhaustion in vivo, shedding light on the molecular mechanisms of T cell dysfunction.

immunology↗

Do light eaters live shorter lives? The case of ultralight Caenorhabditis elegans

The idea that ingesting heavy stable isotopes can increase longevity emerged shortly after the discovery of deuterium in the early 1930s and has been extensively tested since then on animals. Here we present the first experimental evidence for the opposite. Growing C. elegans on bacteria E. coli that are in turn fed on a diet depleted of heavy isotopes of C, H, N and O produced ultralight worms that grow and mature faster but have a shorter lifespan. Based on the differences in expression and solubility of proteins, we established an aging pseudo-time scale. Notably, the newly born ultralight worms appear to be significantly "younger" than their normal counterparts, while at day 10 they are significantly "older". Pathway analysis revealed involvement of mitochondria; analysis of reactive oxygen species (ROS) confirmed significant ROS overproduction in ultralight worms that increases further with age. These findings provide a new modality of affecting the lifespan in this important animal model of human diseases and aging.

biochemistry↗

System-wide profiling by proteome integral solubility alteration assay of drug residence times for target characterization

Most drugs used in the clinic and drug candidates target multiple proteins, and thus detailed characterization of their efficacy targets is required. While current methods rely on quantitative measurements at thermodynamic equilibrium, kinetic parameters such as the residence time of a drug on its target provide a better proxy for efficacy in vivo. Here, we present Residence Time Proteome Integral Solubility Alteration (ResT-PISA) assay which provides monitoring temporal protein solubility profiles after drug removal ("off-curve") in cell lysate or intact cells, quantifying the lifetime of drug-target interaction. A compressed version of the assay measures the integral under the off-curve enabling the multiplexing of binding affinity and residence time assessments into a single proteomic analysis. We introduce a combined scoring system for three parametric dimensions to improve prioritization of targets. By providing complementary information to other characteristics of drug-target interaction, ResT-PISA approach will be useful in drug development and precision medicine.

biochemistry↗