Biology subjects

Archambault, A.-S.

Publications and source records attributed to Archambault, A.-S..

5 recordsLinked to original sources

bioRxiv2026

Mitochondrial transfer mediates metabolic communication between beta cells and islet macrophages

Pancreatic islet macrophages support islet homeostasis and adapt their metabolic program in response to environmental cues, including beta cell released factors. Intercellular mitochondrial transfer is a biological process that modulates cellular responses. To test whether beta cells, which are strongly secretory, transfer mitochondria to islet macrophages, we generated mice with beta cell-specific expression of mitochondrial GFP (PhAMfloxIns1Cre). We demonstrate that beta cells transfer mitochondria to islet macrophages in vivo and in vitro. Diabetogenic stressors did not alter the frequency of mitochondrial transfer and macrophages containing beta cell-derived GFP exhibit increased protein synthesis rates. RNA-seq identified upregulation of activity-regulated cytoskeleton associated protein (Arc) in macrophages receiving beta cell-derived mitochondria, while disruption of actin cytoskeleton dynamics prevented mitochondrial transfer. Together, these findings identify mitochondrial transfer as a previously unrecognized mechanism of beta cell-macrophage communication that may contribute to islet homeostasis and immune regulation.

cell biology↗

bioRxiv2026

Versatile electroporation protocols enable reproducible CRISPR-RNP delivery across multiple primary mouse cells of the hematopoietic lineage

Genetic engineering of primary hematopoietic cells is essential for mechanistic immunology studies, however the development of cell-based therapies yet remains constrained by two major factors: the fragility of many primary lineages and challenges of viral delivery platforms that are costly, time-intensive, and biologically confounding. Here, we optimized scalable, non-viral CRISPR-Cas9 electroporation workflows using the ExPERT platform across three primary mouse hematopoietic cell types: OT-I CD8 T cells, bone marrow-derived macrophages (BMDMs), and hematopoietic stem cells (HSCs). In activated OT-I CD8 T cells, two electroporation programs supported high-efficiency mRNA and RNP delivery with minimal impact on cell viability or proliferative capacity, with subtle activation-state-dependent sensitivity at higher energy settings. Extending optimization to myeloid and stem cell lineages, we found that BMDMs maintained high viability following electroporation, and a high-performing electroporation program supported robust RNP delivery and efficient target gene knockout while preserving macrophage differentiation. In HSCs, the same program enabled consistent RNP delivery, sustained viability, and reproducible gene knockout. Together, these findings establish ExPERT electroporation as a robust, reproducible, and modular platform for non-viral genome editing across primary mouse hematopoietic lineages, lowering barriers to rapid genetic perturbation for both discovery and translational applications.

cell biology↗

bioRxiv2025

Biosynthetic plasticity enables CD8+ T cell functional resilience under nutrient stress

Summary / AbstractTo maintain lineage-specific functions, cells must acquire and allocate nutrients across diverse cellular processes, even in metabolically-dysregulated environments. The mechanisms allowing CD8+ T cells to maintain immune function in perturbed environments are poorly understood. We find that CD8+ T cells adapt to nutrient stresses over time, reconfiguring gene-regulatory and metabolic networks to license functional recovery. Under acute stress, T cells reorient translational programming, limiting nutrient demand while prioritizing stress-sensitive metabolic and transcriptional responses. Within these responses, the transcription factors ATF4 and CEBPG jointly establish an adaptive metabolic program, promoting amino acid synthesis and uptake while maintaining mitochondrial anaplerosis. Despite diminished energetic capacity under environmental stress, this program prevents failure of central carbon metabolism, mitigating stress amplification and cellular dysfunction to potentiate anti-tumor immunity. Altogether, we demonstrate that biosynthetic plasticity via translational and metabolic reprioritization confers functional resilience to immune cells in unfavorable environments, offering novel strategies to enhance immunotherapies.

immunology↗

bioRxiv2023

Inducing an oxidized redox-balance improves anti-tumor CD8+ T cell function

Cancer immunotherapy using antigen-specific CD8+ T cells depends on long-lasting anti-tumor function of the in vitro expanded T cells. T cell function is intricately linked to the activity of many metabolic pathways directly impacting the ability of CD8+ T cells to kill tumor cells. Metabolic conditioning in vitro better prepares CD8+ T cells for in vivo survival, tumor infiltration and tumor clearance. The mechanism underlying in vitro metabolic conditioning-induced augmented in vivo T cell function remains poorly understood. Here we show that metabolic conditioning of CD8+ effector T cells induces an oxidized cellular redox balance at least in part mediated by increased mitochondrial reactive oxygen species (ROS). This redox shift contributes to enhanced in vivo persistence and tumor clearance. In human tumour-infiltrating T cells, altering the redox balance ex-vivo reinvigorated pro-inflammatory cytokine production. Therefore, we believe that redox alterations present a targetable pathway to increase T cell-based anti-tumor immunotherapy efficacy.

immunology↗

bioRxiv2023

A multi-kingdom genetic barcoding system for precise target clone isolation

Clonal heterogeneity underlies diverse biological processes, including cancer progression, cell differentiation, and microbial evolution. Cell tagging strategies with DNA barcodes have recently enabled analysis of clone size dynamics and clone-restricted transcriptomic landscapes of heterogeneous populations. However, isolating a target clone that displays a specific phenotype from a complex population remains challenging. Here, we present a new multi-kingdom genetic barcoding system, CloneSelect, in which a target cell clone can be triggered to express a reporter gene for isolation through barcode-specific CRISPR base editing. In CloneSelect, cells are first barcoded and propagated so their subpopulation can be subjected to a given experiment. A clone that shows a phenotype or genotype of interest at a given time can then be isolated from the initial or subsequent cell pools stored throughout the experimental timecourse. This novel CRISPR-barcode genetics platform provides many new ways of analyzing and manipulating mammalian, yeast, and bacterial systems. TeaserA multi-kingdom CRISPR-activatable barcoding system enables the precise isolation of target barcode-labeled clones from a complex cell population.

synthetic biology↗