La communication scientifique des travaux du LabEx LipSTIC est généralement destinée à un public de spécialistes. Elles font état des travaux en cours et des conclusions disponibles pour la communauté des chercheurs.

février 2, 2022 - Nature Immunology / Bruchard M, Geindreau M, Perrichet A, Truntzer C, Ballot E, Boidot R, Racoeur C, Barsac E, Chalmin F, Hibos C, Baranek T, Paget C, Ryffel B, Rébé C, Paul C, Végran F, Ghiringhelli F

Recruitment and activation of type 3 innate lymphoid cells promote antitumor immune responses

Tumors poorly infiltrated by T cells are more resistant to immunogenic chemotherapies and checkpoint inhibition than highly infiltrated tumors. Using murine models, we found that CCR6+ type 3 innate lymphoid cells (ILC3s) can trigger an increase in the number of T cells infiltrating a tumor. Shortly after administration of cisplatin chemotherapy, production of the chemokine CCL20 and proinflammatory cytokine IL-1β at the tumor site led to the recruitment and activation of ILC3s. Within the tumor, ILC3 production of the chemokine CXCL10 was responsible for the recruitment of CD4+ and CD8+ T lymphocytes to the tumor. ILC3-dependent infiltration of T cells was essential for antitumor immune responses and increased the efficacy of checkpoint inhibition. Thus, we reveal an essential role of CCL20 and IL-1β, which promote ILC3-dependent antitumor immunity and enhance tumor sensitivity to immunotherapy.

septembre 1, 2021 - Biomol Ther (Seoul) / Henusha D Jhundoo / Tobias Siefen / Alfred Liang / Christoph Schmidt / John Lokhnauth / Brice Moulari/ Arnaud Béduneau / Yann Pellequer / Crilles Casper Larsen / Alf Lamprecht

Hyaluronic Acid Increases Anti-Inflammatory Efficacy of Rectal 5-Amino Salicylic Acid Administration in a Murine Colitis Model

5-amino salicylic acid (5-ASA) is a standard therapy for the treatment of mild to moderate forms of inflammatory bowel diseases (IBD) whereas more severe forms involve the use of steroids and immunosuppressive drugs. Hyaluronic acid (HA) is a naturally occurring non-sulfated glycosaminoglycan that has shown epithelium protective effects in experimental colitis recently. In this study, both 5-ASA (30 mg/kg) and HA (15 mg/kg or 30 mg/kg) were administered rectally and investigated for their potential complementary therapeutic effects in moderate or severe murine colitis models. Intrarectal treatment of moderate and severe colitis with 5-ASA alone or HA alone at a dose of 30 mg/kg led to a significant decrease in clinical activity and histology scores, myeloperoxidase activity (MPO), TNF-α, IL-6 and IL-1β in colitis mice compared to untreated animals. The combination of HA (30 mg/kg) and 5-ASA in severe colitis led to a significant improvement of colitis compared to 5-ASA alone. Combined rectal therapy with HA and 5-ASA could be a treatment alternative for severe cases of IBD as it was the only treatment tested that was not significantly different from the healthy control group. This study further underlines the benefit of searching for yet unexplored drug combinations that show therapeutic potential in IBD without the need of designing completely new drug entities.


Are adipokines the missing link between obesity, immune response, and outcomes in severe COVID-19?

Introduction: Obesity is commonly reported in COVID-19 patients and is associated with poorer outcomes. It is suggested that leptin could be the missing link between obesity and severe COVID-19. Our study aimed to unravel the link between adipokines, COVID-19 status, immune response, and outcomes in severe pneumonia.

Methods: In this prospective observational single-center study, 63 immunocompetent patients with severe pneumonia (36 non-COVID-19 and 27 COVID-19) were enrolled, most required intensive care. Clinical and biological characteristics (glucose metabolism, plasma adipokines, and cytokine concentrations) and outcomes were compared.

Results: At similar baseline severity, COVID-19 patients required mechanical ventilation for significantly longer than non-COVID-19 patients (p = 0.0049). Plasma concentrations of leptin and adiponectin were respectively positively and negatively correlated with BMI and glucose metabolism (glycemia and insulinemia), but not significantly different between the two groups. Leptin levels were negatively correlated with IL-1β and IL-6, but the adipokines were not correlated with most other inflammatory mediators, baseline severity (SOFA score), or the duration of mechanical ventilation.

Conclusion: Adipokine levels were correlated with BMI but not with most inflammatory mediators, severity, or outcomes in severe pneumonia, regardless of the origin. The link between obesity, dysregulated immune response, and life-threatening COVID-19 requires further investigation.

Clinical trial: NCT03505281.

avril 28, 2021 - PubMed / Delphine Weil / Vincent Di Martino / Guillaume Mourey / Sabeha Biichle / Adeline Renaudin / Caroline Laheurte / Benoit Cypriani / Eric Delabrousse / Emilie Grandclément / Thierry Thévenot / Philippe Saas / the MICROCIR Study Group

Small Annexin V-Positive Platelet-Derived Microvesicles Affect Prognosis in Cirrhosis: A Longitudinal Study

Introduction: Microvesicles (MVs) with procoagulant properties may favor liver parenchymal extinction, then cirrhosis-related complications and mortality. In a longitudinal cohort of cirrhotic patients, we measured plasma levels of platelet-derived MVs (PMVs), endothelial-derived MVs, and red blood cell-derived MVs, expressing phosphatidylserine (annexin V-positive [AV+]) or not, and evaluated their impact on Model for End-Stage Liver Disease (MELD) score and transplant-free survival.

Methods: MVs were quantified using flow cytometry in plasma from 90 noninfected cirrhotic patients and 10 healthy volunteers matched for age and sex. Impact of plasma microvesicle levels on 6-month transplant-free survival was assessed using log-rank tests and logistic regression.

Results: Microvesicle levels, mostly platelet-derived, were 2.5-fold higher in healthy volunteers compared with cirrhotic patients. Circulating small AV+ PMV levels were lower in cirrhotic patients (P = 0.014) and inversely correlated with MELD scores (R = -0.28; P = 0.0065). During 1-year follow-up, 8 patients died and 7 underwent liver transplantation. In the remaining patients, circulating microvesicle levels did not change significantly. Six-month transplant-free survival was lower in patients with low baseline small AV+ PMV levels (72.6% vs 96.2%; P = 0.0007). In multivariate analyses adjusted for age, ascites, esophageal varices, encephalopathy, clinical decompensation, total platelet counts, MELD score, and/or Child-Pugh C stage, patients with lower small AV+ PMV levels had a significant 5- to 8-fold higher risk of 6-month death or liver transplant. Other PMV levels did not impact on survival.

Discussion: Decreased circulating small AV+ PMV levels are associated with significantly lower transplant-free survival in cirrhotic patients independently of MELD score and platelet counts.