Search results for "Follicular dendritic cells"
showing 10 items of 30 documents
Distinctive Histogenesis and Immunological Microenvironment Based on Transcriptional Profiles of Follicular Dendritic Cell Sarcomas
2017
Abstract Follicular dendritic cell (FDC) sarcomas are rare mesenchymal tumors with variable clinical, morphologic, and phenotypic characteristics. Transcriptome analysis was performed on multiple FDC sarcomas and compared with other mesenchymal tumors, microdissected Castleman FDCs, and normal fibroblasts. Using unsupervised analysis, FDC sarcomas clustered with microdissected FDCs, distinct from other mesenchymal tumors and fibroblasts. The specific endowment of FDC-related gene expression programs in FDC sarcomas emerged by applying a gene signature of differentially expressed genes (n = 1,289) between microdissected FDCs and fibroblasts. Supervised analysis comparing FDC sarcomas with mi…
Ectopic expression of CXCL13, BAFF, APRIL and LT-ß is associated with artery tertiary lymphoid organs in giant cell arteritis
2016
ObjectivesTo investigate whether artery tertiary lymphoid organs (ATLOs) are present in giant cell arteritis (GCA) and that their formation is associated with the ectopic expression of constitutive lymphoid tissue-homing chemokines.MethodsReverse transcriptase PCR, immunohistochemical and immunofluorescence analysis were used to determine the presence of ectopic ATLOs in GCA and the expression of chemokines/chemokine receptors and cytokines involved in lymphoneogenesis in the temporal artery samples obtained from 50 patients with GCA and 30 controls. The presence of lymphatic conduits, of follicular dendritic cells (FDCs) precursors and lymphoid tissue inducer cells was also investigated. F…
Follicular dendritic cells display microvesicle-associated LMP1 in reactive germinal centers of EBV+ classic Hodgkin lymphoma
2018
Expression of the latent membrane protein-1 (LMP1) of Epstein-Barr virus (EBV) was investigated in 153 cases of EBV+ classic Hodgkin lymphoma (cHL); 120 cases were pediatric patients (< 14 years of age) from Iraq, and 33 cases were adult patients from Italy. We describe for the first time the presence of LMP1 protein in EBV-encoded RNA (EBER)-negative follicular dendritic cells (FDCs) of reactive germinal centers (GC) associated with EBV+ cHL. Presence of LMP1+ GCs was independent of geographic region and age of patients. Variable numbers of reactive GCs were present in 22.2% of cases (34 of 153), whereas LMP1 staining of FDCs was present in about a third of cases (10 of 34) with reactiv…
Monocyte-derived inflammatory Langerhans cells and dermal dendritic cells mediate psoriasis-like inflammation
2016
Dendritic cells (DCs) have been implicated in the pathogenesis of psoriasis but the roles for specific DC subsets are not well defined. Here we show that DCs are required for psoriasis-like changes in mouse skin induced by the local injection of IL-23. However, Flt3L-dependent DCs and resident Langerhans cells are dispensable for the inflammation. In epidermis and dermis, the critical DCs are TNF-producing and IL-1β-producing monocyte-derived DCs, including a population of inflammatory Langerhans cells. Depleting Ly6Chi blood monocytes reduces DC accumulation and the skin changes induced either by injecting IL-23 or by application of the TLR7 agonist imiquimod. Moreover, we find that IL-23-…
Focal lymphocytic aggregates in chronic hepatitis C: occurrence, immunohistochemical characterization, and relation to markers of autoimmunity.
1995
Intrahepatic lymphocytic aggregates are observed in chronic hepatitis C as well as in autoimmune chronic hepatitis. Autoantibodies and autoimmune manifestations may occur in hepatitis C. It has been suggested that the lymphocytic aggregates play a role in the liver injury of chronic hepatitis C by an immune-mediated mechanism. We studied the occurrence of intrahepatic lymphocytic aggregates and of autoantibodies in a consecutive series of 128 patients with chronic hepatitis C. For the phenotypic characterization of the lymphocytic aggregates cryostat sections and microwaved paraffin embedded sections were immunostained with monoclonal antibodies directed against T cell subsets, B cells, kil…
A Follicular Dendritic Cell Sarcoma of the Mediastinum With Immature T Cells and Association With Myasthenia Gravis
2010
Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypic features of FDCs. It occurs primarily in lymph nodes but also in extranodal sites. So far, there have been no reports on FDC sarcoma associated with myasthenia gravis. In the following we will present a case of an FDC tumor of the mediastinum associated with paraneoplastic myasthenia gravis in a 39-year-old man. The tumor contained a major proportion of immature T cells, which may be connected to this patient's very unusual clinical presentation with autoimmune phenomena. Extranodal FDC sarcomas still seem hardly noticed, and their clinical and pathologic characteristics remain to be better de…
Mast Cells Induce Migration of Dendritic Cells in a Murine Model of Acute Allergic Airway Disease
2009
<i>Background: </i>The migration of dendritic cells (DCs) from the lungs to the regional lymph nodes is necessary for the development of allergic airway disease. Following activation, mast cells release a variety of stored or de novo-produced inflammatory mediators, several of them being capable of activating DCs. In this study, the role of mast cells on DC migration from the lungs to the thoracic lymph nodes was investigated in sensitized mice. <i>Methods:</i> Mast cell-deficient mice (Kit<sup>W-sh/W-sh</sup>) and their wild-type counterparts were sensitized intraperitoneally with ovalbumine (OVA) in saline and challenged by a single intranasal administr…
The matricellular protein SPARC supports follicular dendritic cell networking toward Th17 responses.
2011
Abstract Lymphnode swelling during immune responses is a transient, finely regulated tissue rearrangement, accomplished with the participation of the extracellular matrix. Here we show that murine and human reactive lymph nodes express SPARC in the germinal centres. Defective follicular dendritic cell networking in SPARC-deficient mice is accompanied by a severe delay in the arrangement of germinal centres and development of humoral autoimmunity, events that are linked to Th17 development. SPARC is required for the optimal and rapid differentiation of Th17 cells, accordingly we show delayed development of experimental autoimmune encephalomyelitis whose pathogenesis involves Th17. Not only h…
The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of human hematopoietic progenitor cells capable to differentiate into funct…
2000
Abstract Objective . Hyper-IL-6, a fusion protein of interleukin-6 and its specific receptor, together with stem cell factor leads to the proliferation of primitive hematopoietic progenitor cells. Based on these findings, the current study examined whether hyper-IL-6 promotes the growth of precursor cells that can be further differentiated into dendritic cells in the presence of additional cytokines. Methods . Dendritic cell cultures were generated from CD34 + hematopoietic progenitor cells derived either from bone marrow or from peripheral blood. CD34 + cells were cultured in the presence of cytokines for 2 weeks and then used for phenotyping and T-cell stimulation assays. Results . Hyper-…
Inhibitors of β-catenin affect the immuno-phenotype and functions of dendritic cells in an inhibitor-specific manner
2015
Many tumors are characterized by mutation-induced constitutive activation of β-catenin which promotes tumor growth and survival. Consequently, the development of specific β-catenin inhibitors for tumor therapy has come into the focus of drug development. β-Catenin was also shown to contribute to the tolerance-promoting function of unstimulated dendritic cells (DCs). In response to activation, DCs acquire potent T cell stimulatory capacity and induce profound tumor antigen-specific immune responses. Here we asked for effects of pre-clinically established β-catenin inhibitors (CCT-031374, iCRT-5, PNU-75654) on mouse bone marrow-derived (BM)DCs. All three inhibitors moderately increased surfac…