Search results for "T cell"
showing 10 items of 2228 documents
Diffuse Type of Giant-Cell Tumor of Tendon Sheath: An Ultrastructural Study of Two Cases With Cytogenetic Support
2002
Two cases of the diffuse type of giant-cell tumor of the tendon sheath (GCTTS) are described. Both tumors arose in the vicinity of large joints of the lower extremity, showing similar clinical and radiological features. Histologically, a proliferation of polygonal mononuclear cells was seen, together with osteoclastlike giant cells, foam cells, and siderophages. The tumors were poorly delineated, displaying an infiltrative pattern into the neighboring soft tissues. Immunohistochemically, strong expression of vimentin, neuron-specific enolase, A1-antitrypsin, and CD68 was found in both mono- and multinucleated tumor cells. At the ultrastructural level, mononuclear cells revealed a diverse mo…
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…
Immune-mediated necrotizing myopathy is characterized by a specific Th1-M1 polarized immune profile.
2012
Immune-mediated necrotizing myopathy (IMNM) is considered one of the idiopathic inflammatory myopathies, comprising dermatomyositis, polymyositis, and inclusion body myositis. The heterogeneous group of necrotizing myopathies shows a varying amount of necrotic muscle fibers, myophagocytosis, and a sparse inflammatory infiltrate. The underlying immune response in necrotizing myopathy has not yet been addressed in detail. Affected muscle tissue, obtained from 16 patients with IMNM, was analyzed compared with eight non-IMNM (nIMNM) tissues. Inflammatory cells were characterized by IHC, and immune mediators were assessed by quantitative real-time PCR. We demonstrate that immune- and non–immune-…
Stimulation of T cells by autologous mononuclear leukocytes and epidermal cells in psoriasis.
1986
Based on reports suggesting aberrant cell-mediated immunity and altered infiltration of immunocompetent cells into the skin in psoriasis, we studied the stimulation of T cells by autologous non-T mononuclear leukocytes (autologous mixed lymphocyte reaction, AMLR) and by epidermal cells isolated from lesional and clinically uninvolved skin in psoriasis (autologous mixed epidermal cell lymphocyte reaction, AMECLR). Age- and sex-matched individuals served as controls. We found that the AMLR in psoriasis (n = 11) was similar to that in healthy controls (n = 16); furthermore, cell proliferation was alike in the presence of either 5% AB-serum or autologous serum. By contrast, while the AMECLR in …
Presence of estrogen-binding sites on macrophage-like synoviocytes and cd8+, cd29+, cd45ro+ t lymphocytes in normal and rheumatoid synovium
1993
Objective. To study the presence of estrogen-binding sites (EBS) in the synovial tissues of male and female patients with rheumatoid arthritis (RA) and in age and sex-matched healthy controls. Methods. Both type 1 (high affinity, low binding capacity) and type 2 (reduced affinity, higher binding capacity) EBS were investigated in both soluble and nuclear fractions of homogenized synovial tissue samples by a dextran-coated charcoal method. To determine what type of synovial cell was positive for EBS, cryosections of synovial tissues were immunostained with a specific monoclonal anti–estrogen receptor antibody (anti-ER MAb) using both immunofluorescence and immunoperoxidase techniques. Double…
IL-10 and IL-10 receptor overexpression in oral giant cell lesions
2010
Objective: Central giant cell lesions (CGCL) and peripheral giant cell lesions (PGCL) occur in the jaws and contain osteoclast-like giant cells and mononuclear cells positive for the macrophage marker CD68. The participation of immune-inflammatory mechanisms has been proposed in the lesions development. As IL-10 is one of the most important anti-inflammatory cytokines and it is also an inhibitory cytokine to macrophage function and bone resorption, the purpose of the present study was to investigate its expression together with its receptor (IL-10R?) in CGCL and PGCL. Study Design: Six fragments of CGCL and seven fragments of PGCL were obtained by surgical excision. Frozen specimens were cu…
Clinicopathologic features of nasopalatine duct cysts: A retrospective study in two Brazilian oral and maxillofacial pathology referral centers
2021
Background Nasopalatine duct cyst (NDC) is the most common non-odontogenic cyst in the oral cavity. Clinically it is not difficult to suspect these lesions based on clinical and radiographic appearance. However, the histopathological diagnosis may be difficult due to the broad morphological diversity of these lesions. The objective was to analyze the clinicopathological features of NDCs diagnosed in two oral and maxillofacial pathology services in the Brazilian northeast. Material and Methods A retrospective clinicopathologic study was performed. A total of 18,121 clinical records of oral lesions from two oral and maxillofacial pathology services in Brazil were analyzed (2000-2020). All NDC…
Functional profile of cytomegalovirus (CMV)-specific CD8+ T cells and kinetics of NKG2C+ NK Cells associated with the resolution of CMV DNAemia in al…
2011
Immune mechanisms involved in control of cytomegalovirus (CMV) infection in the allogeneic stem cell transplantation setting have not been fully disclosed. CMV pp65 and IE-1-specific CD8(+) T cells expressing IFN-γ, TNF-α, and CD107a, alone or in combination, and NKG2C(+) NK cells were prospectively enumerated during 13 episodes of CMV DNAemia. The expansion of monofunctional and polyfunctional CD8(+) T cells was associated with CMV DNAemia clearance. The size and functional diversity of the expanding CD8(+) T-cell population was greater in self-resolved episodes than in episodes treated with antivirals. These differences were related to the magnitude of expansion of cognate antigen IFN-γ C…
Accumulation of dysfunctional effector CD8+T cells in the liver of patients with chronic HCV infection
2005
Background/Aims Hepatitis C virus (HCV) causes a chronic infection that can lead to fibrosis and carcinoma. Immune responses mediated by cytotoxic T lymphocytes (CTLs) could be involved in viral clearance or persistence, and therefore in determining the course of the disease. Methods Intrahepatic and peripheral blood CD8+T cells were obtained from 32 HCV-chronically infected patients and analysed by flow-cytometry for surface markers of differentiation, IFNγ and TNFα production, degranulation capacity and perforin content, after CD3 triggering. Results were compared with those obtained from 13 patients with a non-viral liver disease. Results Intrahepatic CD8+T cells of HCV-infected patients…
Reduction of plasma granzyme A correlates with severity of sepsis in burn patients.
2009
The risk of mortality is high in burn patients and correlates with age, burn area extent, and sepsis. Immunosuppression has been reported to occur after severe burn. Cytotoxic cells possess specialized granules containing perforin and a group of serine proteases (granzymes). Granzyme A is a serine protease constitutively expressed by gammadelta and NK cells, in agreement with their functional cytolytic potential. In vitro studies have shown that GrA may be released extracellularly during cytotoxic cell degranulation, indicating the activation of cytotoxic cells. The aim of our study was to determine plasma GrA activity in burned patients and to verify if decreased GrA levels were associated…