Functional discrimination between normal centroblast and centrocyte obtained from human inflamed tonsils after cell sorting.
CXCR4 expression functionally discriminates centroblasts versus centrocytes within human germinal center B cells.
Specimen part
View SamplesTo explore events that govern the differentiation of human nave B cells (NBCs) into memory B cells and plasma cells (PCs), we designed an in vitro 2-step culture model leading non-switched NBC precursors to differentiate into two cell compartments: CD20loCD38hi and CD20+CD38+.
IL-2 requirement for human plasma cell generation: coupling differentiation and proliferation by enhancing MAPK-ERK signaling.
Specimen part, Subject, Time
View SamplesAkirin2 is an evolutionally conserved nuclear protein involved in the regulation of a set of inflammatory gene expression in various cell types.
Akirin2 is critical for inducing inflammatory genes by bridging IκB-ζ and the SWI/SNF complex.
Specimen part
View SamplesGEP on Affymetrix Genechip HTA 2.0 microarrays was performed on ex vivo cell-sorted GC-Tfh and pre-Tfh from TONS and FL
Human Lymphoid Stromal Cells Contribute to Polarization of Follicular T Cells Into IL-4 Secreting Cells.
Specimen part, Treatment
View SamplesGEP on Affymetrix U133+2.0 microarrays was performed on in vitro expanded stromal cells
Human Lymphoid Stromal Cells Contribute to Polarization of Follicular T Cells Into IL-4 Secreting Cells.
Specimen part
View SamplesTumor infiltrating neutrophils (TAN) have been shown to exert both pro- and anti-tumoral activities and their recruitment and polarization are triggered by tumor-derived signals. Resident mesenchymal stromal cells (MSC) could contribute to tumor-supportive cell niche and have been shown to display tumor-specific transcriptomic, phenotypic, and functional features compared to normal tissue. In our study, we investigate whether these two cell subsets establish a bidirectional crosstalk in the context of B-cell lymphoma.
Neutrophils trigger a NF-κB dependent polarization of tumor-supportive stromal cells in germinal center B-cell lymphomas.
Treatment
View SamplesFCRL4 is an immunoregulatory receptor that belongs to the Fc receptor-like (FCRL) family. In healthy individuals, this protein is specifically expressed by memory B cells (MBCs) and is preferentially localized in subephitelial regions of lymphoid tissues. An expansion of FCRL4+ B cells has been shown in blood or other tissues in various infectious or autoimmune pathologies. In the present work, we generated and characterized in vitro FCRL4+ B cells from purified MBCs using T-dependent and/or T-independent stimulation. FCRL4+ B cells account for 17% of cells generated at day-4 of culture. Transcriptomic and phenotypic analysis of FCRL4+ cells show that they are closely related to FCRL4+ tonsillar MBCs. Interestingly, these cells highly express inhibitory receptors genes as described for exhausted FCRL4+ MBCs in the blood of HIV-viremic individuals. In agreement, in vitro generated FCRL4+ B cells show a significant underexpression of cell cycle genes with a two fold weaker number of cell division compared to FCRL4- cells. Finally, resulting from their reduced proliferation and differentiation potential, we show that FCRL4+ cells are not prone to generate plasma cells, contrary to FCRL4- cells. Given the difficulty to access to in vivo FCRL4+ cells, our in vitro model could be of major interest to study the biology of normal and pathological FCRL4+ cells.
Characterization of human FCRL4-positive B cells.
Specimen part
View SamplesGEP on Affymetrix U133+2.0 microarrays was performed on ex vivo cell-sorted Tfh from FL or TONS
CD10 delineates a subset of human IL-4 producing follicular helper T cells involved in the survival of follicular lymphoma B cells.
Specimen part, Treatment
View SamplesHuman bone marrow mesenchymal stromal cells (BM-MSC) could be committed toward a functional lymphoid-like stroma by a combination of TNFalpha (TNF) and Lymphotoxin alpha1/beta2 (LT) (Am-Thomas et al Blood 2007).
Mesenchymal stromal cells orchestrate follicular lymphoma cell niche through the CCL2-dependent recruitment and polarization of monocytes.
Sex, Specimen part, Treatment
View SamplesBRAF oncogene is mutated in ~50% of human cutaneous melanomas. The BRAF V600E mutation leads to constitutive activation of the mitogen-activated protein kinase (MAPK) pathway fuelling cancer growth. The inhibitors of BRAF V600E (BRAFi), lead to massive and high response rate. However, BRAFi-resistant cells that operate as a cellular reservoir for relapses severely limits the duration of the clinical response. The recent depiction of these resistant cells did not identify druggable targets to ensure long-term survival under BRAFi. Here, we identify the aryl hydrocarbon receptor (AhR) as a target to eradicate resistant cells. We show that BRAFi bind to AhR on a new site, named beta-pocket, and reprogram gene expression independently of its partner ARNT. beta-pocket activation induces a pigmentation signature, which is associated to BRAFi-induced cell death of sensitive BRAF V600E melanoma cells and tumour shrinkage. Intriguingly, in resistant cells, BRAFi does not induced a pigmentation signature since these cells display another AhR program; AhR-ARNT dependant. By this way, AhR directs several key BRAFi-resistant genes. At single cell level, this constitutive activation of AhR-ARNT is identified in rare cells before BRAFi-treatment of melanoma tumours and an enrichment of these alpha-cells is observed under BRAFi. Our data strongly suggest that an endogenous AhR ligand activates AhR-ARNT via the canonical AhR pocket (alpha-pocket), thus favouring BRAFi-resistant gene expression. Importantly, we identify the clinically compatible AhR antagonist, the resveratrol (RSV), able to abrogate the deleterious constitutive activation of AhR and to reduce the cellular reservoir for the relapse. Taken together, this work reveals that constitutive AhR signalling drives BRAFi resistance and constitutes a therapeutic target to achieve long-term patient survival under BRAFi. More broadly, the constitutive activation of AhR by endogenous ligands is in line with the ability of UV radiations to generate potent AhR ligands and to favour melanoma onset. Overall design: Total RNA isolated from 12 human melanoma cell lines (501Mel) after different treatments was subjected to multiplexed RNA-sequencing using Illumina NextSeq500 sequencing tehnology.
Sustained activation of the Aryl hydrocarbon Receptor transcription factor promotes resistance to BRAF-inhibitors in melanoma.
Specimen part, Cell line, Subject
View Samples