Project description:B cells with regulatory functions have been described both in immune homeostasis in healthy volunteers and in different pathological conditions. Whereas Il-10 secreting B cells represent the main subset described, recently, a subset of B cells secreting granzyme B (GZMB+) was evidenced in a growing numbers of immunological contexts, autoimmunity, chronic infections and neoplasias. Until now, no phenotype has been evidenced for these GZMB+ B cells and their regulatory functions as well are still to clarify.
Project description:Transcriptional profiling of human peripheral B cell subsets sorted by flow cytometry based on the secretion of IL-10 in response to CpG2006 stimulation. Goal was to identify molecular markers to distinguish IL-10-producing B cells form non-IL-10-producing B cells. Two-condition experiment, non-IL-10-secreting B cells vs. IL-10-secreting B cells. Healthy donors. Biological replicates: 6
Project description:Proteoglycans (PGs) are proteins with glycosaminoglycan (GAG) chains, such as chondroitin sulfate (CS) or heparan sulfate (HS), attached to serine residues. We have earlier shown that prohormones can carry CS, thus, constituting a novel class of PGs. The mapping of GAG modifications of proteins in endocrine cells may thus assist us in delineating possible roles of PGs in endocrine cellular physiology. With this aim, we applied a glycoproteomic approach to identify PGs, their GAG chains and their attachment sites in insulin-secreting cells. Glycopeptides carrying GAG chains were enriched from human pancreatic islets, rat (INS-1 832/13) and mouse (MIN6, NIT-1) insulinoma cell lines by ion exchange chromatography, depolymerized with GAG lyases, and analyzed by nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS). We identified CS modifications of chromogranin-A, islet amyloid polypeptide, secretogranin 1 and secretogranin 2, immunoglobulin superfamily member 10, and protein AMBP. Additionally, we identified two HS-modified prohormones (chromogranin-A and secretogranin-1), which was surprising, as prohormones are not typically regarded as HSPGs. For chromogranin-A, the glycosylation site carried either CS or HS, making it a so-called hybrid site. Additional HS sites were found on syndecan-1, syndecan-4, nerurexin-2, protein NDNF, and testican-1. These results demonstrate that several prohormones, and other constituents of the insulin-secreting cells are PGs. Cell-targeted mapping of the GAG glycoproteome forms an important basis for better understanding of endocrine cellular physiology, and the novel CS and HS sites presented here provide important knowledge for future studies.
Project description:Resistance towards anti-angiogenic therapy (AAT) still represents a substantial clinical challenge. We report here that tumor-infiltrating mast cells (MC) are powerful mediators decreasing efficacy of AAT in mice and cancer patients. They act in a cell-extrinsic manner by secreting granzyme B, which liberates pro-angiogenic mediators from the extracellular matrix. In addition, MC also diminish efficacy of anti-angiogenic agents in a cell-autonomous way, which can be blocked by the mast cell degranulation inhibitor cromolyn. Our findings are relevant in humans because patients harboring higher numbers of MC in their tumors have an inferior outcome after anti-angiogenic treatment in the Gepar Quinto randomized Phase 3 clinical trial. Thus, MC-targeting might represent a novel promising approach to increase efficacy of AAT.
Project description:We measured genes expression differences in antibody secreting cells from LynKO mice in following treatment with a BMI-1 inhibitor (PTC-028) or a vehicle control. BMI-1 inhibition lead to a reduction in antibody secreting cells in LynKO mice and in humans donors. We performed RNA sequencing to understand the impact of BMI-1 inhibition on antibody secreting cells in LynKO mice.
Project description:Corticotropin (ACTH)-secreting pituitary adenomas give rise to a severe endocrinological disorder, i.e., Cushing’s disease, with multifaceted clinical presentation and treatment outcomes. Experimental studies suggested that disease variability is inherent to the pituitary tumor, thus pointing to the need for further studies into tumor biology. Aim of the present study was to evaluate transcriptome expression pattern in a large series of ACTH-secreting pituitary adenoma specimens, in order to identify molecular signatures of these tumors. Gene expression profiling of formalin-fixed paraffin-embedded specimens from 40 human ACTH-secreting pituitary adenomas revealed significant expression of genes involved in protein biosynthesis and ribosomal function, in keeping with neuroendocrine cell profile. Unsupervised cluster analysis identified three distinct gene profile clusters and several genes were uniquely overexpressed in a given cluster, accounting for different molecular signatures. Of note, gene expression profiles were associated with clinical features such as age and size of the tumor. Altogether, our study shows that corticotrope tumors are characterized by neuroendocrine gene expression profile and present subgroup-specific molecular features.
Project description:Following activation by cognate antigen, B cells undergo fine-tuning of their antigen receptors and may ultimately differentiate into antibody-secreting cells (ASCs). While antigen-specific antibodies from B cell receptor (BCR) expressing B cells can be readily cloned and sequenced following flow sorting, antigen-specific plasma cells that lack surface BCR cannot be easily profiled in a high-throughput way. Here, we report an approach, TRAPnSeq (antigen specificity mapping through Ig secretionTRAPandSequencing), that allows capture of secreted antibodies on the surface of ASCs, which in turn enables high-throughput screening of single ASCs against large antigen panels and recovery of paired VH:VL antibody sequences. This approach incorporates flow cytometry, standard microfluidic platforms and DNA barcoding technologies to isolate and characterize antigen-specific ASCs through single cell V(D)J, RNA and antigen barcode sequencing. We show the utility of TRAPnSeq by profiling antigen-specific IgG and IgE plasma cells from mouse and humans and validate antigen binding by ELISA. TRAPnSeq can easily be combined with existing B cell platforms to accelerate antibody discovery from ASCs and can further be expanded to any protein secreting-cells.
Project description:The CD19 positive antibody secreting cells (ASC) in both bone marrow (BM) have the capacity to provide immune memory in addition to cells traditionally considered long-lived, the CD19-negative BM ASC. We performed flow cytometry (FCM) immunophenotyping, fluorescence-activated cell sorting (FACS) for cell subset isolation, ELISpot assays detecting the isotype of antibody secretion as well as antibodies against vaccine derived antigens, and comparative gene expression analyses of CD19- ASC, CD19+ ASC, CD20- B cells, and CD20+ B cells from BM. The findings may aid in the understanding of the differential cell subsets created through vaccination and lead to improved vaccine strategies and production. FACS sorted tissue B cells and antibody secreting cell subset gene expression.