Search results for "T cell"
showing 10 items of 2228 documents
Impaired cellular immune responses in chronic renal failure: Evidence for a T cell defect
1986
Impaired cellular immune responses in chronic renal failure: Evidence for a T cell defect. Cellular immune responses in vitro were studied in 24 patients on chronic hemodialysis and 16 healthy volunteers with normal kidney function. Patients on maintenance hemodialysis had lymphopenia with diminished numbers of both T4 + and T8 + T-lymphocytes. The T4/T8 ratios were within the normal range. Peripheral blood lymphocytes (PBL) showed a diminished proliferative response upon stimulation with concanavalin A, phytohemagglutinin and poke weed mitogen. When cell surface antigens were used for stimulation (mixed lymphocyte culture) uremic lymphocytes also showed a lower proliferation rate. Although…
Vaccination with Mage-3a1 Peptide–Pulsed Mature, Monocyte-Derived Dendritic Cells Expands Specific Cytotoxic T Cells and Induces Regression of Some M…
1999
Dendritic cells (DCs) are considered to be promising adjuvants for inducing immunity to cancer. We used mature, monocyte-derived DCs to elicit resistance to malignant melanoma. The DCs were pulsed with Mage-3A1 tumor peptide and a recall antigen, tetanus toxoid or tuberculin. 11 far advanced stage IV melanoma patients, who were progressive despite standard chemotherapy, received five DC vaccinations at 14-d intervals. The first three vaccinations were administered into the skin, 3 × 106 DCs each subcutaneously and intradermally, followed by two intravenous injections of 6 × 106 and 12 × 106 DCs, respectively. Only minor (less than or equal to grade II) side effects were observed. Immunity t…
The viral clearance in interferon-treated chronic hepatitis C is associated with increased cytotoxic T cell frequencies
1999
Abstract Background/Aims: Cytotoxic T lymphocytes have been demonstrated in peripheral blood and liver tissue of patients with chronic hepatitis C virus infection, but their significance for viral clearance is unknown. Therefore, we analyzed hepatitis C virus-specific cytotoxic T lymphocyte precursor frequencies in chronic hepatitis C virus carriers during interferon-α treatment. Methods: Blood mononuclear cells or CD8+ T cells from HLA-A2 positive and negative patients and controls were analyzed in chromium-release assays using a panel of 18 synthetic peptides from the HCV core, E1 and NS4 antigens bearing HLA-A2 binding motifs. Specific cytotoxic T lymphocyte precursor frequencies were st…
Relevance of gamma interferon, tumor necrosis factor alpha, and interleukin-10 gene polymorphisms to susceptibility to Mediterranean spotted fever.
2009
Several studies have demonstrated that cellular immunity plays a critical role in the protective immune response against Rickettsia conorii. Immune CD4+ and CD8+ T cells are both involved in the control of rickettsial infection (38). Perivascular infiltrated CD4+ and CD8+ T lymphocytes, macrophages, and natural killer cells produce chemokines and cytokines that activate endothelial rickettsicidal activities. Infected human cells, including endothelial cells, hepatocytes, and macrophages, activated by gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β), kill intracellular rickettsiae by one or a combination of three mechanisms, involving nitric oxide syn…
NK/T-cell lymphomas 'nasal type': an italian multicentric retrospective survey
2006
Abstrac Objective: To evaluate the clinical characteristics and outcome of NK/T-cell lymphoma ‘nasal type’ developed in Italian patients. Patients: Between 1997 and 2004, 26 new cases of NK/T-cell lymphoma ‘nasal type’ were diagnosed in 10 Italian Hematology institutions. Results: All patients were Caucasian, male/female ratio was 19/7, with a median age of 50 years (range 20–80). In 23 cases presentation at the onset was in the nasal cavity or adjacent structures, in two cases the lymphoma onset with skin lesions was followed successively by rhynopharyngeal dissemination, while the remaining case had bone marrow and lymph node involvement followed by oro-pharyngeal involvement. Regarding t…
Characterization of the Microenvironment in Positive and Negative Sentinel Lymph Nodes from Melanoma Patients
2015
Melanomas are aggressive skin tumors characterized by high metastatic potential. Our previous results indicate that Natural Killer (NK) cells may control growth of melanoma. The main defect of blood NK cells was a decreased expression of activating NCR1/NKp46 receptor and a positive correlation of NKp46 expression with disease outcome in stage IV melanoma patients was found. In addition, in stage III melanoma patients, we identified a new subset of mature NK cells in macro-metastatic Lymph nodes (LN). In the present studies, we evaluated the numbers of NK cells infiltrating primary cutaneous melanoma and analyzed immune cell subsets in a series of sentinel lymph nodes (SLN). First, we show …
Expression of Matrix-Degrading Cysteine Proteinase Cathepsin K in Cholesteatoma
2001
Cholesteatoma is a nonneoplastic lesion of the middle ear space or mastoid that is histologically characterized by a progressive bone erosion of the ossicles and surrounding bone. Several matrix-degrading enzymes have been implicated as mediators of this bone erosion. Because the novel cysteine proteinase cathepsin K has been shown to play a central role in bone resorption, we examined the expression of this enzyme in tissue specimens of cholesteatoma. Tissue specimens of 9 patients with cholesteatoma were obtained during middle-ear surgery. Expression of cathepsin K mRNA was determined by RT-PCR using specific primers. Immunohistochemical analysis of cathepsin K protein expression in tissu…
Flow cytometric analysis of conjunctival epithelium in ocular rosacea and keratoconjunctivitis sicca
2000
Abstract Purpose To investigate by flow cytometry and impression cytology (IC) specimens the inflammatory status of the conjunctival epithelium and goblet cell density in two series of patients with rosacea and dry eye syndrome compared with a population of healthy subjects. Design Nonrandomized, prospective, comparative case series. Participants Twenty-six eyes of 13 patients with rosacea, 26 eyes of 13 patients with dry eye syndrome, and 24 eyes of 12 control subjects were included in this study. Methods IC specimens were collected after clinical examination of the ocular surface and analyzed by flow cytometry, using antibodies directed to human lymphocyte antigen-DR (HLA-DR), intercellul…
Involvement of the CD95 (APO-1/Fas) receptor and ligand system in Helicobacter pylori-induced gastric epithelial apoptosis.
1998
Helicobacter pylori infection is associated with chronic gastritis, peptic ulceration, and gastric carcinoma. The potential role of CD95-mediated apoptosis was investigated in a panel of gastric biopsies obtained from patients with H. pylori-associated chronic gastritis (n = 29) and with noninfected normal mucosa (n = 10). Immunohistochemistry revealed increased CD95 receptor expression in epithelial and lamina propria cells in chronic gastritis. By in situ hybridization, CD95 ligand mRNA was absent or low in normal mucosa but expressed at high levels in lamina propria lymphocytes and, unexpectedly, in epithelial cells in chronic gastritis. Apoptotic cells were rare in normal mucosa but wer…
The effect of surgical suture material on osteoclast generation and implant-loosening
2020
Background: Implant loosening - either infectious or aseptic- is a still a major complication in the field of orthopaedic surgery. In both cases, a pro-inflammatory peri-prosthetic environment is generated by the immune system - either triggered by bacteria or by implant wear particles - which leads to osteoclast differentiation and osteolysis. Since infectious cases in particular often require multiple revision surgeries, we wondered whether commonly used surgical suture material may also activate the immune system and thus contribute to loss of bone substance by generation of osteoclasts. Methods: Tissue samples from patients suffering from infectious implant loosening were collected intr…