Search results for "pathogen"
showing 10 items of 1657 documents
Increased Goodpasture antigen-binding protein expression induces type IV collagen disorganization and deposit of immunoglobulin A in glomerular basem…
2007
Increased expression of Goodpasture antigen-binding protein (GPBP), a protein that binds and phosphorylates basement membrane collagen, has been associated with immune complex-mediated pathogenesis. However, recent reports have questioned this biological function and proposed that GPBP serves as a cytosolic ceramide transporter (CERTL). Thus, the role of GPBP in vivo remains unknown. New Zealand White (NZW) mice are considered healthy animals although they convey a genetic predisposition for immune complex-mediated glomerulonephritis. Here we show that NZW mice developed age-dependent lupus-prone autoimmune response and immune complex-mediated glomerulonephritis characterized by elevated GP…
Analysis of the antibody repertoire in tears of dry-eye patients.
2001
<i>Purpose:</i> It has recently been suggested that dry-eye disease has an underlying autoimmune mechanism. This hypothesis is further supported by the successful treatment of the disease with immunomodulatory drugs such as cyclosporin A. Although it is known that tears contain antibodies, very little is known about the antibody repertoires in tears. It was the aim of this study to analyze the IgA antibody repertoire against ocular antigens in the tears of patients suffering from dry-eye disease and compare it to those of healthy volunteers. <i>Methods:</i> Two groups were examined: 20 healthy volunteers (controls) and 28 patients suffering from dry-eye disease. The …
Immunohistological differential diagnosis of inflammatory colonic diseases.
1984
Immunohistological investigations were carried out on human colonic tissue from, I healthy mucosa, 2 slightly inflamed mucosa, 3 mucosa with ulcerative colitis, 4 mucosa with Crohn's colitis, using antibodies against immunoglobulins and complement components. All our antibodies, including F(ab')2 fragments, demonstrated a progressive increase of labelled cells from healthy mucosa through slightly inflamed mucosa to mucosa with ulcerative colitis, in contrast to a complete absence of labelled cells in cases of Crohn's disease. The results are discussed with regard to their pathogenesis and their clinical significance for the differentiation of ulcerative colitis and Crohn's colitis.
Macrophages Escape Inhibition of Major Histocompatibility Complex Class I-Dependent Antigen Presentation by Cytomegalovirus
2000
ABSTRACTThe mouse cytomegalovirus (MCMV)m152- andm06-encoded glycoproteins gp40 and gp48, respectively, independently downregulate major histocompatibility complex (MHC) class I surface expression during the course of productive MCMV infection in fibroblasts. As a result, presentation of an immediate-early protein pp89-derived nonapeptide toH-2Ld-restricted CD8+cytotoxic T cells is completely prevented in fibroblasts. Here we demonstrate that MCMV-infected primary bone marrow macrophages and the macrophage cell line J774 constitutively present pp89 peptides during permissive MCMV infection to cytotoxic T lymphocytes (CTL). In contrast to fibroblasts, expression of them152andm06genes in macr…
Toll-like receptors – sentries in the B-cell response
2009
Summary Toll-like receptors (TLR) play a central role in the initiation of the innate immune response to pathogens. Upon recognition of molecular motifs specific for microbial molecules TLR mediate pro-inflammatory cytokine secretion and enhance antigen presentation; in B cells they further promote expansion, class switch recombination and immunoglobulin secretion. As a result of their adjuvant properties, TLR ligands have become an integral component of antimicrobial vaccines. In spite of this, little is known of the direct effects of TLR engagement on B-lymphocyte function. The scope of this review is to outline the differences in TLR expression and reactivity in murine and human B-cell s…
B cell activating factor (BAFF): Structure, functions, autoimmunity and clinical implications in Systemic Lupus Erythematosus (SLE)
2020
The B cell activating factor (BAFF), or B lymphocyte stimulator (BLyS), is a B cell survival factor which supports autoreactive B cells and prevents their deletion. BAFF expression is closely linked with autoimmunity and is enhanced by genetic alterations and viral infections. Furthermore, BAFF seems to be involved in adipogenesis, atherosclerosis, neuro-inflammatory processes and ischemia reperfusion (I/R) injury. BAFF is commonly overexpressed in Systemic Lupus Erythematosus (SLE) and strongly involved in the pathogenesis of the disease. The relationship between BAFF levels, disease activity and damage accrual in SLE is controversial, but growing evidence is emerging on its role in renal …
Interferon-regulatory factor 4 is essential for the developmental program of T helper 9 cells.
2010
Summary Interferon-regulatory factor 4 (IRF4) is essential for the development of T helper 2 (Th2) and Th17 cells. Herein, we report that IRF4 is also crucial for the development and function of an interleukin-9 (IL-9)-producing CD4 + T cell subset designated Th9. IRF4-deficient CD4 + T cells failed to develop into IL-9-producing Th9 cells, and IRF4-specific siRNA inhibited IL-9 production in wild-type CD4 + T cells. Chromatin-immunoprecipitation (ChIP) analyses revealed direct IRF4 binding to the Il9 promoter in Th9 cells. In a Th9-dependent asthma model, neutralization of IL-9 substantially ameliorated asthma symptoms. The relevance of these findings is emphasized by the fact that the ind…
Novel Paraoxonase 2-Dependent Mechanism Mediating the Biological Effects of the Pseudomonas aeruginosa Quorum-Sensing Molecule N-(3-Oxo-Dodecanoyl)-l…
2015
ABSTRACT Pseudomonas aeruginosa produces N -(3-oxo-dodecanoyl)- l -homoserine lactone (3OC12), a crucial signaling molecule that elicits diverse biological responses in host cells thought to subvert immune defenses. The mechanism mediating many of these responses remains unknown. The intracellular lactonase paraoxonase 2 (PON2) hydrolyzes and inactivates 3OC12 and is therefore considered a component of host cells that attenuates 3OC12-mediated responses. Here, we demonstrate in cell lines and in primary human bronchial epithelial cells that 3OC12 is rapidly hydrolyzed intracellularly by PON2 to 3OC12 acid, which becomes trapped and accumulates within the cells. Subcellularly, 3OC12 acid acc…
Enrichment of Immediate-Early 1 (m123/pp89) Peptide-Specific CD8 T Cells in a Pulmonary CD62LloMemory-Effector Cell Pool during Latent Murine Cytomeg…
2000
ABSTRACTInterstitial cytomegalovirus (CMV) pneumonia is a clinically relevant complication in recipients of bone marrow transplantation (BMT). Recent data for a model of experimental syngeneic BMT and concomitant infection of BALB/c mice with murine CMV (mCMV) have documented the persistence of tissue-resident CD8 T cells after clearance of productive infection of the lungs (J. Podlech, R. Holtappels, M.-F. Pahl-Seibert, H.-P. Steffens, and M. J. Reddehase, J. Virol. 74:7496–7507, 2000). It was proposed that these cells represent antiviral “standby” memory cells whose functional role might be to help prevent reactivation of latent virus. The pool of pulmonary CD8 T cells was composed of two…
Complex Cellular Responses of Helicobacter pylori-Colonized Gastric Adenocarcinoma Cells ▿
2011
ABSTRACT Helicobacter pylori is an important class I carcinogen that persistently infects the human gastric mucosa to induce gastritis, gastric ulceration, and gastric cancer. H. pylori pathogenesis strongly depends on pathogenic factors, such as VacA (vacuolating cytotoxin A) or a specialized type IV secretion system (T4SS), which injects the oncoprotein CagA (cytotoxin-associated gene A product) into the host cell. Since access to primary gastric epithelial cells is limited, many studies on the complex cellular and molecular mechanisms of H. pylori were performed in immortalized epithelial cells originating from individual human adenocarcinomas. The aim of our study was a comparative anal…