Project description:Expression of germinal center T follicular helper (GC-Tfh) cells and pre-Tfh cells from tonsils (Tons) and follicular lymphoma lymph nodes (FL).
Project description:Human B cell lymphomas such as Follicular Lymphoma (FL) and Chronic Lymphocytic Leukemia/Small lymphocytic lymphoma (CLL) grow in lymph nodes in areas defined as malignant follicles, and proliferation centers, respectively. We used single-cell RNA-sequencing to study the tumor microenvironment of human lymph nodes involved by FL and CLL.
Project description:Here we show a newly identified human Innate Lymphoid Cell population present in the follicles of tonsils and lymph nodes termed follicular regulatory ILCs (ILCFR). ILCFR have a distinct phenotype and transcriptional program when compared to other defined ILCs. Surprisingly, ILCFR inhibit the ability of follicular helper T (Tfh) cells to provide B cell help. The localization of ILCFR to the germinal centers suggests these cells may interfere with germinal center B cell (GC-B) and germinal center Tfh cell (GC-Tfh) interactions through the production of transforming growth factor beta (TGF-b). Intriguingly, under conditions of impaired GC-Tfh-GC-B cell interactions, such as human immunodeficiency virus (HIV) infection, the frequency of these cells is increased. Overall, we predict a role for ILCFR in regulating GC-Tfh-GC-B cell interactions and propose they expand in chronic inflammatory conditions.
Project description:Loss of Elp3 in CD4 T cells hindered the development of an optimal T follicular helper T cell (TFH) response. To understand the molecular pathway by which Elp3 is necessary for TFH responses, mice deficient for Elp3 in T cells and WT littermate were immunized with ovalbumin emulsified with complete Freund Adjuvant. 8 days later, TFH were sorted from the draining lymph nodes and submitted for RNAseq
Project description:To characterize the effect of loss of Ets1 in Non-TFH and TFH cells, we performed gene expression RNAseq analysis for T follicular helper (TFH) and Non-T follicular helper (Non-TFH) cells in WT (Ets1 fl/fl) and Ets1 KO (CD4-cre Ets1 fl/fl) mice.
Project description:GEP on Affymetrix U133+2.0 microarrays was performed on ex vivo cell-sorted Tfh from FL or TONS GEP was performed on 7 Tfh from FL and 7 Tfh from TONS
Project description:Background: Patients with common variable immunodeficiency (CVID) suffer from hypogammaglobulinemia due to an inadequate differentiation of long-lived humoral immunity in germinal centers (GC). Objective: To further characterize the transcriptome and phenotype of T follicular helper (TFH) cells as key players in the GC reaction of CVID patients. Methods: Sorted TFH cells from CVID lymph nodes and healthy control tonsils were analyzed by bulk-RNA-sequencing. Altered protein expression was verified by flow cytometry and CyTOF analysis. Tissue localization of cells was determined by multi-fluorescence imaging. Results: Transcriptome analysis of sorted TFH cells revealed an enrichment of cytotoxicity-associated gene sets in CVID patients. Extended immune phenotyping identified different cytotoxic CD4 memory populations expressing T-bet, EOMES, CRTAM, Perforin, and Granzyme A and B. Two clusters co- expressing markers of TFH differentiation such as CXCR5, ICOS, and PD1 were expanded in CVID lymph nodes. One of them additionally expressed high levels of FoxP3. Histological sections confirmed the increase in Granzyme-B+EOMES+ CD4 cells in GCs of patients’ lymph nodes. Only few of these cells circulate in peripheral blood. Discussion: Our study reports for the first time that the previously reported type 1 polarization in lymph nodes of CVID patients is associated with an expansion of two distinct cytotoxic CD4 TFH cell clusters within GCs which were very rare in peripheral blood. Further investigations directly in secondary tissues are required to explore their role in the GC failure in CVID.
Project description:In this experiment we generated Affymetrix gene expression data for T Follicular Helper (TFH) cells from tonsils of healthy volunteers (4 biological replicates) and naive CD4-positive helper T cells (2 biological replicates). TFH cells provide a model relevant to SLE as TFH operate upstream of the activation of pathogenic autoantibody-producing B cells during the disease. This experiment accompanies promoter capture-C and ATAC-seq experiments on the same cell types.
Project description:Comparison of gene expression profiles of follicular lymphoma vs. reactive lymph nodes. 8 cases of follicular lymphoma; 5 cases of reactive lymph nodes.
