Biology subjects

Dulong, J.

Publications and source records attributed to Dulong, J..

3 recordsLinked to original sources

bioRxiv2026

NFATc2 potentiates DNA double-strand breaks repair by interaction with Ku80 in radiotherapy patients

A fraction of patients treated with radiotherapy are known to be more sensitive to ionizing radiations. Skin fibroblasts from such radiosensitive individuals exhibit a higher cellular toxicity after irradiation and a delay in DNA repair. Deciphering the molecular mechanisms underlying these cellular defects is thus of major importance. We previously observed that the transcription factor NFATc2 is expressed at a reduced level in fibroblasts from radiosensitive patients. The present work aimed to elucidate the role of NFATc2 in the regulation of DNA repair, particularly the repair of radiation-induced double-strand breaks. We demonstrate an interaction of NFATc2 with the NHEJ repair protein Ku80 and observe that the NFATc2 RHD domain is necessary and sufficient for this interaction. Moreover, we show that NFATc2-Ku80 complexes are not colocalized to DNA double-strand breaks sites suggesting an involvement upstream of the DNA repair pathway. The silencing of NFATc2 impairs the NHEJ repair activities by delaying Ku70-Ku80 interaction in the early steps of this pathway. Finally, stable over-expression of NFATc2 in patients fibroblasts partially rescues their defective DNA repair phenotype, especially in the most radiosensitive cells. Altogether, our data reveal that NFATc2 is a regulator of DNA repair in skin fibroblasts and therefore a potential modulator of cellular radiosensitivity.

cell biology↗

bioRxiv2024

Senescent fibroblasts support tumor growth by inducing immune cell death in humanized models

Syngeneic mouse tumor models have shown that senescence influences the tumor immune response in multiple ways, including the induction of an immunosuppressive microenvironment or the promotion of immune cell recruitment. Yet, the impact of senescence on the tumor immune response in a humanized setting remains largely unexplored. To address this, we employed tumor spheroids and mice bearing tumors immunogenic to human immune cells derived from the same donor. We found that senescent fibroblasts exert a dual effect by enhancing the recruitment of immune cells into the tumor microenvironment while simultaneously promoting the apoptosis of T and NK cells. Mechanistically, we demonstrate that this apoptosis is primarily due to increased Fas ligand (FasL) expression on the surface of senescent fibroblasts. Deletion of FasL on fibroblasts was sufficient to prevent immune cell death and increase tumor cell killing. Our results highlight the importance of evaluating the impact of therapy-induced senescence in humanized models to understand and predict the outcome of cancer treatments.

cancer biology↗

bioRxiv2020

Mass cytometry and artificial intelligence define CD169 as a specific marker of SARS-CoV2-induced acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is the main complication of COVID-19, requiring admission to Intensive Care Unit (ICU). Despite recent immune profiling of COVID-19 patients, to what extent COVID-19-associated ARDS specifically differs from other causes of ARDS remains unknown, To address this question, we built 3 cohorts of patients categorized in COVID-19negARDSpos, COVID-19posARDSpos, and COVID-19posARDSneg, and compared their immune landscape analyzed by high-dimensional mass cytometry on peripheral blood followed by artificial intelligence analysis. A cell signature associating S100A9/calprotectin-producing CD169pos monocytes, plasmablasts, and Th1 cells was specifically found in COVID-19posARDSpos, unlike COVID-19negARDSpos patients. Moreover, this signature was shared by COVID-19posARDSneg patients, suggesting severe COVID-19 patients, whatever they experienced or not ARDS, displayed similar immune dysfunctions. We also showed an increase in CD14posHLA-DRlow and CD14lowCD16pos monocytes correlated to the occurrence of adverse events during ICU stay. Our study demonstrates that COVID-19-associated ARDS display a specific immune profile, and might benefit from personalized therapy in addition to standard ARDS management. One Sentence SummaryCOVID-19-associated ARDS is biologically distinct from other causes of ARDS.

immunology↗