Biology subjects

Le Gallou, S.

Publications and source records attributed to Le Gallou, S..

3 recordsLinked to original sources

bioRxiv2022

Single-cell profiling identifies clinically relevant interactions between tumor associated macrophages and blood endothelial cells in diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) are the two most common B-cell lymphomas and are characterized by a dynamic crosstalk between tumor B cells and a heterogeneous tumor-supportive microenvironment, including immune, endothelial, and stromal components. Although their impact on the pathogenesis and prognosis of B-cell lymphoma has been acknowledged for years, tumor-associated macrophages (TAM) have not been extensively explored in DLBCL and FL. Herein, we investigate mononuclear phagocytes (MNP) heterogeneity at the single cell level and their potential co-regulation with the stromal and endothelial compartments in B-cell lymphoma lymph nodes compared to reactive secondary lymphoid organs, using a combination of mass cytometry, single cell RNA sequencing, and in silico approaches. We reveal a co-regulation between TAM and blood endothelial cells (BEC) in lymphoma. Moreover, we identify a specific interaction between Annexin A1 (ANXA1)-expressing BEC and formyl-peptide receptors (FPR1/2)-expressing monocytes/macrophages in DLBCL, which we confirm in situ by multiplex immunofluorescence and imaging mass cytometry. This crosstalk is associated to an immunosuppressive tumor microenvironment and an adverse prognosis in DLBCL.

immunology↗

bioRxiv2021

Nonclassical monocytes are prone to migrate into tumor in diffuse large B-cell lymphoma

Absolute count of circulating monocytes has been proposed as an independent prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, monocyte nomenclature includes various subsets with pro-, anti-inflammatory, or suppressive functions, and their clinical relevance in DLBCL has been poorly explored. Herein, we broadly assessed circulating monocyte heterogeneity in 91 DLBCL patients. Classical- (cMO, CD14pos CD16neg) and intermediate- (iMO, CD14pos CD16pos) monocytes accumulated in DLBCL peripheral blood and exhibited an inflammatory phenotype. On the opposite, nonclassical monocytes (ncMO, CD14low CD16pos) were decreased in peripheral blood. Tumor-conditioned monocytes presented similarities with ncMO phenotype from DLBCL and were prone to migrate in response to CCL3, CCL5, and CXCL12, and presented similarities with DLBCL-infiltrated myeloid cells, as defined by mass cytometry. Finally, we demonstrated the adverse value of an accumulation of nonclassical monocytes in 2 independent cohorts of DLBCL. Key pointsO_LINonclassical monocytes are prone to migrate to DLBCL tumor C_LIO_LIHigh count of circulating nonclassical monocytes is an independent adverse event in DLBCL C_LI

immunology↗

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↗