Biology subjects

Granjeaud, S.

Publications and source records attributed to Granjeaud, S..

3 recordsLinked to original sources

bioRxiv2026

ADAM10 tailors extracellular vesicles for content transfer rather than signaling by contact

Etxtracellular vesicles (EVs) support cell-to-cell communication, both in physiological and pathological contexts and emerge as new biomarkers and potential therapeutics. Yet, despite EVs holding huge promises, our understanding of core mechanisms governing EV signaling remains significantly underdeveloped. Our previous work indicated that syndecans and their cytosolic adaptor syntenin control the biogenesis of a major subset of small EVs (sEVs). Here we show that syndecans control the accumulation of ADAM10 into sEVs. ADAM10 promotes the formation of sEVs enriched in cleaved receptors (reducing sEV corona), supports the sorting of proteins with intracellular functions, and tailors sEVs for the delivery of their internal content, e.g. syntenin, into the cytosol of recipient cells. Conversely, inhibition of ADAM10 favors the production of sEVs bearing full-length, signaling-competent receptors/ligands and enhances contact-dependent signaling. These findings uncover a protease-regulated switch that tailors sEV composition and signaling modality, providing important new mechanistic insights into the core molecular pathways supporting EV-mediated communication.

cell biology↗

bioRxiv2025

Build heatmaps of cell frequencies and marker intensities for correct interpretations

High-content cytometry is an important technique in clinical research, producing data that is rich and complex to analyze. The resulting clusters of cells must be profiled to determine their role and function, and analyzed to identify changes in cell frequency or marker intensity. The heat map is the most suitable tool for presenting this information in a synthetic way. However, its construction must be adapted to the information and the objective. Here we describe the step-by-step construction of heat maps of marker intensity and cell frequency using Excel, Phantasus or R, including the conversion of numbers to colors and the organization of rows and columns. Researchers who master these steps will be able to correctly interpret heat maps and derive the most benefit from high-content cytometry.

bioinformatics↗

bioRxiv2020

Two new immature and dysfunctional neutrophil cell subsets define a predictive signature of sepsis useable in clinical practice

Sepsis is the leading cause of death in adult intensive care units. At present, sepsis diagnosis relies on non-specific clinical features. It could transform clinical care to have objective immune cell biomarkers that could predict sepsis diagnosis and guide treatment. For decades, neutrophil phenotypes have been studied in sepsis, but a diagnostic cell subset has yet to be identified. Here, high dimensional mass cytometry was used to reveal for the first time a specific neutrophil signature of sepsis severity that does not overlap with other inflammatory biomarkers, and that distinguishes patients with sepsis from those with non-infectious inflammatory syndrome. Unsupervised analysis of 42-dimesional mass cytometry data characterized previously unappreciated heterogeneity within the CD64+ immature neutrophils and revealed two new subsets distinguished by CD123 and PD-L1 expression. These immature neutrophils exhibited diminished activation and phagocytosis functions. The proportion of CD123-expressing neutrophils also correlated with clinical severity. Critically, this study showed that these two new neutrophil subsets were specific to sepsis and detectable by routine flow cytometry using seven markers. The demonstration here that a simple blood test distinguishes sepsis from other inflammatory conditions represents a key biological milestone that can be immediately translated into improvements in patient care. One Sentence SummaryCD123+ and/or PD-L1+ immature and dysfunctional neutrophil subsets identified by mass cytometry, define an early human blood signature of sepsis

immunology↗