Search results for "B-Lymphocytes"
showing 10 items of 186 documents
Histomorphological and Immunophenotypic Features of Pill-Induced Esophagitis.
2015
The aim of this study was to investigate histomorphological and immunophenotypic features in pill-induced esophagitis. We comparatively evaluated the histomorphological, immunophenotypic features of pill-induced esophagitis vs. reflux esophagitis, as well as clinical information and endoscopic findings. Fifty-two tissue pieces from 22 cases of pill-induced esophagitis, 46 pieces from 20 reflux esophagitis, and 16 pieces from 14 control samples were subjected to immunohistochemistry for inflammatory infiltrates (CD3 for T lymphocyte, CD20 for B lymphocyte, CD56 for NK cell, CD68 for macrophage, CD117 for mast cell) and eosinophil chemotaxis-associated proteins (Erk, leptin, leptin receptor, …
Local reactions to tick bites
2008
A retrospective histological and immunohistochemical study has been carried out in 25 cases of tick bites recorded in our Departments. The samples that included an attached tick showed a cement cone anchoring the mouthparts to the skin and a blood-soaked, spongiform appearance of the superficial dermis, with a mild neutrophilic and eosinophilic infiltration. The vessels displayed a loose multilayered endothelial proliferation, with plump endothelia, permeated with erythrocytes. A few of them were severed, allowing copious blood extravasation. The established lesions included the following: erythema chronicum migrans-like cases, foreign body granulomas-sometimes containing remnants of the mo…
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-…
Tumour necrosis factor (TNF) production by T cell receptor-primed T lymphocytes is a target for low dose methotrexate in rheumatoid arthritis
1999
SUMMARYMethotrexate (MTX) is an effective immunosuppressive agent in various chronic inflammatory diseases such as rheumatoid arthritis (RA). However, its mechanisms of action are only partially understood. In this study, we assessed the effects of MTX on the differentiation of peripheral blood (PB) CD4+CD45RA ‘naive’ and CD4+CD45RO ‘memory’ T cells from healthy controls and patients with RA. Accordingly, purified T cells were primed and restimulated in vitro via the T cell receptor (TCR) in the presence of IL-2 to generate effector T cells secreting large amounts of Th1 and Th2 cytokines. We observed that low doses of MTX strongly suppress TNF and to a lesser extent interferon-gamma (IFN-γ…
Competition between clonal plasma cells and normal cells for potentially overlapping bone marrow niches is associated with a progressively altered ce…
2011
Disappearance of normal bone marrow (BM) plasma cells (PC) predicts malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) into symptomatic multiple myeloma (MM). The homing, behavior and survival of normal PC, but also CD34 hematopoietic stem cells (HSC), B-cell precursors, and clonal PC largely depends on their interaction with stromal cell-derived factor-1 (SDF-1) expressing, potentially overlapping BM stromal cell niches. Here, we investigate the distribution, phenotypic characteristics and competitive migration capacity of these cell populations in patients with MGUS, SMM and MM vs healthy adults (HA) aged 60 years. Our result…
Interleukin-5 production by mononuclear cells from aged individuals: implication for autoimmunity.
1999
It is well known that in the elderly a deterioration of immune functions may occur. Particularly, stimulation of T cells from aged individuals leads to different kind and/or size of responses if compared with the responses obtained from T cells from young individuals. At the same time, an increase in prevalence of autoantibodies occurs in elderly. The altered production of certain cytokines might explain this paradox of decreased responsiveness to foreign antigens in the face of an increased response to self-antigens. We and others have suggested that this kind of immune response might depend on an age-associated impairment of Th-1 type function that selectively affects production of cytoki…
Immunologic effects of rituximab on the human spleen in immune thrombocytopenia
2011
Abstract Immune thrombocytopenia (ITP) is an autoimmune disease with a complex pathogenesis. As in many B cell–related autoimmune diseases, rituximab (RTX) has been shown to increase platelet counts in some ITP patients. From an immunologic standpoint, the mode of action of RTX and the reasons underlying its limited efficacy have yet to be elucidated. Because splenectomy is a cornerstone treatment of ITP, the immune effect of RTX on this major secondary lymphoid organ was investigated in 18 spleens removed from ITP patients who were treated or not with RTX. Spleens from ITP individuals had follicular hyperplasia consistent with secondary follicles. RTX therapy resulted in complete B-cell de…
B cells in the aged: CD27, CD5, and CD40 expression.
2003
Ageing is characterized by numerous changes in lymphocyte subpopulations. In the present paper we have focused on B cells carrying the surface markers CD27, CD5 and CD40. CD27 is considered a marker of primed (memory) cells and its engagement promotes the differentiation of memory B cells into plasma cells. CD5 is expressed on B1 cells, which are considered to be responsible for T cell-independent antibody production other than autoantibodies. The CD40 molecule binds CD40L (CD154) and is necessary for T-dependent antibody responses. Here we show that the absolute number of CD5+ and CD40+ B cells is decreased in the elderly, while CD27+ B lymphocytes only marginally decrease in centenarians.…
Immunoregulatory role of Jα281 T cells in aged mice developing lupus-like nephritis
2007
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the emergence of autoreactive T cells. Humans and mice with SLE have reduced numbers of CD1d-restricted invariant natural killer T (iNKT) cells, suggesting a key role for these cells in its immunopathogenesis. This subset uses an invariant TCR constituted by Valpha14 Jalpha281 chains paired with some Vbeta domains. The regulatory role for iNKT cells in non-autoimmune mice was suggested by our previous results showing that aged Jalpha281 knockout (KO) mice produce anti-dsDNA. Here we show that old Jalpha281 KO mice have proteinuria and antibodies against dsDNA and cardiolipin. Histological analysis of Jalpha281 KO m…
Activation by mitogens and superantigens of axolotl lymphocytes: functional characterization and ontogenic study.
1996
Urodele amphibians have weak and slow immune responses compared to mammals and anuran amphibians. Using new culture conditions, we tested the ability of lymphocytes of a well-studied salamander, the Mexican axolotl (Ambystoma mexicanum) to proliferate in vitro with diverse mitogenic agents. We demonstrated that the axolotl has a population of B lymphocytes that proliferate specifically and with a high stimulation index to the lipopolysaccharide (LPS) known as a B-cell mitogen in mammals. This proliferative capacity is observed without significant changes throughout ontogenesis. In the presence of LPS, axolotl B lymphocytes are able to synthesize and secrete both isotopes of immunoglobulin d…