Introduction: Hyporesponsiveness of human lamina propria immune cells to microbial and nutritional antigens represents one important feature of intestinal homeostasis. It is at least partially mediated by low expression of the innate response receptors CD11b, CD14, CD16 as well as the cystine-glutamate transporter xCT on these cells. Milieu-specific mechanisms leading to the down-regulation of these receptors on circulating monocytes, the precursor cells of resident macrophages, are mostly unknown.
View Article and Find Full Text PDFThe potential advantage of using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) methodology to detect metastasis in sentinel lymph nodes (SLNs) of breast cancer (BC) patients was evaluated in this prospective study. We measured the expression of relevant gene transcripts in SLNs using an innovative algorithm and compared the results of single-marker assays versus multi-marker assays with conventional histological detection methods. SLNs from women aged ≥ 18 years diagnosed with unilateral BC were examined by haematoxylin-eosin staining and immunohistochemistry and analysed for transcripts of several relevant genes using qRT-PCR (learning group).
View Article and Find Full Text PDFBackground: Pancreatic cancer (PaCa) is a fatal human cancer due to its exceptional resistance to all current anticancer therapies. The cytoprotective enzyme heme oxygenase-1 (HO-1) is significantly overexpressed in PaCa and seems to play an important role in cancer resistance to anticancer treatment. The inhibition of HO-1 sensitized PaCa cells to chemo- and radiotherapy in vitro.
View Article and Find Full Text PDFBackground & Aims: T-cell receptor reactivity of intestinal lamina propria T cells (LP-T) critically depends on the capacity of local accessory cells to secrete cysteine. For T cells, cysteine is the limiting precursor for glutathione synthesis, a prerequisite for antigen-dependent proliferation. We aimed to determine the role of the redoxactive microenvironment for hyporeactivity of LP-T in normal human gut vs hyperreactivity of LP-T in inflammatory bowel disease.
View Article and Find Full Text PDFRecently, we established a pharmacodynamic assay to monitor immunosuppressive effectiveness of cyclosporine A (CsA) in patients on standard CsA regimen. The aim of the present study was to extend this correlation to reduced CsA regimen and to compare pharmacodynamic and kinetic parameters to allow prediction of rejections and infections. In 53 heart allograft recipients, nuclear factor of activated T cells (NFAT)-regulated gene expression was quantified at trough (C0) and 2-h post-CsA dose (C2).
View Article and Find Full Text PDFBackground: Concentrations of proinflammatory cytokines are increased in the intestinal mucosa of patients with active Crohn's disease (CD). In a prospective study we investigated whether cytokines can predict long-term remission (>6 months) in patients with steroid-refractory CD receiving treatment with infliximab or cyclophosphamide, followed by azathioprine or methotrexate.
Methods: Cytokine transcripts were quantified using real-time polymerase chain reaction (PCR) in mucosal biopsies from 19 patients with active, steroid-refractory CD before and 8 weeks after initiation of therapy.
Background: It has been suggested that Crohn's disease (CD) is associated with an exaggerated T-helper 1 cytokine response manifested by increased production of interleukin (IL)-12. IL-12 is a heterodimeric protein comprising 2 disulfide-linked subunits designated p35 and p40. Recently, IL-12-related cytokines, IL-23 and IL-27, were described.
View Article and Find Full Text PDFThioredoxin (TRX) is a ubiquitous oxidoreductase with strong co-cytokine, chemoattractant and anti-apoptotic activities. TRX expression was found to be particularly elevated in the intestinal mucosa, where its physiologic function is entirely unknown. Here, we demonstrate a high level of TRX expression in lamina propria T cells (LP-T) as opposed to autologous peripheral blood T lymphocytes (PB-T).
View Article and Find Full Text PDFOxidative compounds that are physiologically generated in vivo can induce natural defense mechanisms to enhance the elimination of pathogens and to limit inflammatory tissue damage in the course of inflammation. Here, we have investigated WF10, a chlorite-based non-toxic compound for its functional activities on human PBMC in vitro. WF10 exerts potent immune-modulatory effects through generating endogenous oxidative compounds such as taurine chloramine.
View Article and Find Full Text PDFTreatment with the anti-tumour necrosis factor alpha chimeric monoclonal antibody infliximab is highly effective in the treatment of refractory and fistulising Crohn's disease. Infliximab has been tolerated well, with minimal and short-lived adverse effects. The likelihood of severe reactions to infliximab, such as acute and delayed hypersensitivity infusion reactions, is small; nevertheless, if they do occur, they are life-threatening.
View Article and Find Full Text PDFThe formation of supramolecular activation clusters within the immunological synapse, crucial for sustained signaling and T lymphocyte activation, requires costimulation-dependent reorganization of the actin cytoskeleton. Here we have identified the actin-remodeling protein cofilin as a key player in this process. Cell-permeable peptides that block costimulation-induced cofilin/F-actin interactions in untransformed human T lymphocytes impair receptor capping and immunological synapse formation at the interface between T cells and antigen-presenting cells.
View Article and Find Full Text PDFBackground And Aims: Immunoregulatory properties of cytokines may contribute to pathological immune reactions in inflammatory bowel disease. There is an urgent need for a simple and dependable means for quantitating inflammatory activity in mucosal biopsies and assessing relapse risk particularly in patients with active Crohn's disease (CD).
Patients And Methods: Cytokine and chemokine transcripts were quantified using real-time PCR in mucosal biopsy specimens from 70 patients with active inflammatory bowel disease (CD, n=45; ulcerative colitis n=25) and 16 patients with specific colitis (ischemic colitis, infectious colitis).
Arzneimittelforschung
August 2003
Functional characterization and quality control of complex biological pharmaceuticals are currently difficult to achieve. Classical analytical methods are not suitable due to the heterogeneity of such substances. Conventional biological assays based on the detection of proteins and functional physiologic responses are highly variable in sensitivity and therefore, difficult to standardize.
View Article and Find Full Text PDFTo define mediator profiles in inflamed and noninflamed areas in inflammatory bowel disease (IBD) we analyzed the expression of 35 messenger-RNAs (mRNAs) encoding cytokines, chemokines, and some related molecules in transmural gut tissues (n=138) from patients with ulcerative colitis (UC), Crohn's disease (CD), and inflammatory and normal controls by real-time quantitative reverse transcription polymerase chain reaction. Using sample collectives with a comparable degree of inflammation, most parameters investigated showed similarly increased mRNA expression levels in both active UC and CD. This included proinflammatory cytokines, but also interferon (IFN) gamma and several IFN-gamma inducible chemokines.
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