Search

Objective.Rheumatoid arthritis (RA) is associated with damage of the articular cartilage and the periarticular bone. While imaging of bone damage has substantially improved in recent years, direct imaging of the articular cartilage of the hand joints in patients with RA is still challenging. The study used T2 mapping of the finger joints to assess cartilage damage in RA.Methods.Magnetic resonance imaging (MRI) at 3 Tesla was done in 30 patients with RA, and T2 relaxation times visualizing alteration in the collagen network and hydration of articular cartilage were mapped in 6 cartilage regions of the metacarpophalangeal (MCP) joints 2 and 3. Values were related to autoantibody status [anticitrullinated protein antibodies (ACPA), rheumatoid factor (RF)], disease duration, and disease activity as well as sex and age of the patients.Results.T2 relaxation times could be reliably measured in the 6 regions of the MCP joints. Significantly higher relaxation times indicating more advanced cartilage alterations were observed in the metacarpal heads of ACPA-positive (p = 0.001–0.010) and RF-positive patients (p = 0.013–0.025) as well as those with longer disease duration (> 3 yrs; p = 0.028–0.043). Current disease activity, sex, and age did not influence T2 relaxation times.Conclusion.These data show that cartilage damage can be localized and quantified in the hand joints of patients with RA by T2 mapping. Further, ACPA and RF positivity as well as disease duration appear to be the crucial factors influencing cartilage damage.

BACKGROUND: Human rhinoviruses (HRV) are one of the main causes of virus induced asthma exacerbations. Infiltration of B lymphocytes into the subepithelial tissue of the lungs has been demonstrated during rhinovirus infection in allergic individuals. However, the mechanisms through which HRVs modulate the immune responses of monocytes and lymphocytes are not yet well described. OBJECTIVE: To study the dynamics of virus uptake by monocytes and lymphocytes, and the ability of HRVs to induce activation of in vitro cultured human peripheral blood mononuclear cells. METHODS: Flow cytometry was used for the enumeration and characterization of lymphocytes. Proliferation was estimated using (3) H-thymidine or CFSE labelling and ICAM-1 blocking. We used bead based multiplex assays and quantitative PCR for cytokine quantification. HRV accumulation and replication inside B lymphocytes was detected by a combination of in situ hybridation (ISH), immunofluorescence and with PCR for positive strand and negative strand viral RNA. Cell images were acquired with imaging flow cytometry. RESULTS: By means of imaging flow cytometry, we demonstrate a strong and quick binding of HRV types 16 and 1B to monocytes, and slower interaction of these HRVs with CD4+ T cells, CD8+ T cells and CD19+ B cells. Importantly, we show that HRVs induce the proliferation of B cells while addition of anti-ICAM-1-antibody partially reduces this proliferation for HRV16. We prove with ISH that HRVs can enter B cells, form their viral replication centers and the newly formed virions are able to infect HeLa cells. In addition, we demonstrate that similarly to epithelial cells, HRVs induce the production of pro-inflammatory cytokines in PBMCs. CONCLUSION: Our results demonstrate for the first time that HRVs enter and form viral replication centers in B lymphocytes and induce the proliferation of B cells. Newly formed virions have the capacity to infect other cells (HeLa). These findings indicate that the regulation of human rhinovirus induced B cell responses could be a novel approach to develop therapeutics to treat the virus-induced exacerbation of asthma. This article is protected by copyright. All rights reserved.

Die Technische Universitaet (TU) Darmstadt stellt eine Untersuchung vor, deren erster Teil zu Leuchtdichtemessungen von kuenstlich verschmutzten Scheinwerfern im Labor bei der SAE-Tagung 2010 praesentiert wurde. Der vorliegende Beitrag beschreibt eine Feldstudie zur Wirksamkeit und zum Nutzen von Scheinwerferreinigungsanlagen (SRA) im Strassenverkehr. Bei niedrigen Verschmutzungsgraden im Sommer zeigte sich kein Nutzen, jedoch stellte sich bei hoeheren Verschmutzungsgraden und anderer Zusammensetzung des Schmutzes im Winter eine mittlere Reinigungswirkung ein. Die Blendung wird verringert und die Ausleuchtung durch die Scheinwerfer verbessert. Eine Modellrechnung sagt einen Zugewinn bei der Erkennbarkeitsentfernung vorher. Sehr viele Faktoren beeinflussen allerdings den Reinigungsprozess. Ziel ist es die mittlere Reinigungswirkung im Winter zu erhoehen und die grosse Streuung zu reduzieren. Die Ergebnisse werden dargestellt und die Auswirkungen auf Blendung und Erkennbarkeitsentfernung abgeschaetzt.

A restriction endonuclease activity from Sulfolobus islandicus REN2H1 was purified by phosphocellulose and cation exchange chromatography. The enzyme cuts DNA at the recognition site GCwGC as could be shown by restriction analysis of plasmids and short synthetic duplex DNA. The cleavage occurs after the first guanosine base and is inhibited by 5-methyl-cytosine methylation. The restriction activity is salt-sensitive and has an optimal activity around 70 degrees C.

Calcium is a key regulator of cardiac function and is modulated through the Ca2+-sensor protein S100A1. S100 proteins are considered to exert both intracellular and extracellular functions on their target cells. Here we report the impact of an increased intracellular S100A1 protein level on Ca2+-homeostasis in neonatal ventricular cardiomyocytes in vitro. Specifically, we compare the effects of exogenously added recombinant S100A1 to those resulting from the overexpression of a transduced S100A1 gene. Extracellularly added S100A1 enhanced the Ca2+-transient amplitude in neonatal ventricular cardiomyocytes (NVCMs) through a marked decrease in intracellular diastolic Ca2+-concentrations ([Ca2+]i). The decrease in [Ca2+]i was independent of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) activity and was probably the result of an increased sarcolemmal Ca2+-extrusion through the sodium-calcium exchanger (NCX). At the same time the Ca2+-content of the sarcoplasmic reticulum (SR) decreased. These effects were dependent on the uptake of extracellularly added S100A1 protein and its subsequent routing to the endosomal compartment. Phospholipase C and protein kinase C, which are tightly associated with this subcellular compartment, were found to be activated by endocytosed S100A1. By contrast, adenoviral-mediated intracellular S100A1 overexpression enhanced the Ca2+-transient amplitude in NVCMs mainly through an increase in systolic [Ca2+]i. The increased Ca2+-load in the SR was based on an enhanced SERCA2a activity while NCX function was unaltered. Overexpressed S100A1 colocalized with SERCA2a and other Ca2+-regulatory proteins at the SR, whereas recombinant S100A1 protein that had been endocytosed did not colocalize with SR proteins. This study provides the first evidence that intracellular S100A1, depending on its subcellular location, modulates cardiac Ca2+-turnover via different Ca2+-regulatory proteins.

Background Allergen specific immunotherapy (SIT) faces problems related to side effects and limited efficacy. Direct administration of allergen extracts into lymph nodes induces increased specific IgG production and T cell responses using significantly lower allergen doses. Methods In this study mechanisms of immune regulation by MAT vaccines in vitro and in allergen SIT of cat Allergic rhinitis patients who received 3 inguinal intra lymph node injections of MAT Fel d 1 vaccine were investigated in PBMC and cell cultures for specific T cell proliferation Fel d 1 tetramer specific responses and multiple immune regulatory molecules. Results MAT Fel d 1 vaccine was efficiently internalized by antigen presenting cells. This was followed by precaspase 1 cleavage to caspase 1 and secretion of IL 1ß indicating inflammasome activation. Mat Fel d 1 induced specific T cell proliferation and an IL 10 and IFN ? dominated T cell responses with decreased Th2 cytokines at 100 times lower doses than Fel d 1. Induction of immune tolerance by MAT Fel d 1 ILIT involved multiple mechanisms of immune suppression. Early Fel d 1 specific T cell activation was followed by full T cell unresponsiveness to allergen after 1 year in the MAT Fel d 1 group characterized by increased allergen specific T regulatory cells decreased circulating Fel d 1 tetramer positive cells increased IL 10 and FOXP3 expression and change in the HR2/HR1 ratio toward HR2. Conclusions This study demonstrates the induction of allergen tolerance after 3 intra lymph node injections of MAT Fel d 1 vaccine mediated by increased cellular internalization of the allergen activation of inflammasome and generation of allergen specific peripheral T cell tolerance. © 2014 John Wiley Sons A/S. Published by John Wiley Sons Ltd.

Background Distinct human IL-10–producing B-cell subsets with immunoregulatory properties have been described. However, the broader spectrum of their direct cellular targets and suppressive mechanisms has not been extensively studied, particularly in relation to direct and indirect IL-10–mediated functions. Objective The aim of the study was to investigate the effects of IL-10 overexpression on the phenotype and immunoregulatory capacity of B cells. Methods Primary human B cells were transfected with hIL-10, and IL-10–overexpressing B cells were characterized for cytokine and immunoglobulin production by means of specific ELISA and bead-based assays. Antigen presentation, costimulation capacity, and transcription factor signatures were analyzed by means of flow cytometry and quantitative RT-PCR. Effects of IL-10–overexpresing B cells on Toll-like receptor–triggered cytokine release from PBMCs, LPS-triggered maturation of monocyte-derived dendritic cells, and tetanus toxoid–induced PBMC proliferation were assessed in autologous cocultures. Results IL-10–overexpressing B cells acquired a prominent immunoregulatory profile comprising upregulation of suppressor of cytokine signaling 3 (SOCS3), glycoprotein A repetitions predominant (GARP), the IL-2 receptor α chain (CD25), and programmed cell death 1 ligand 1 (PD-L1). Concurrently, their secretion profile was characterized by a significant reduction in levels of proinflammatory cytokines (TNF-α, IL-8, and macrophage inflammatory protein 1α) and augmented production of anti-inflammatory IL-1 receptor antagonist and vascular endothelial growth factor. Furthermore, IL-10 overexpression was associated with a decrease in costimulatory potential. IL-10–overexpressing B cells secreted less IgE and potently suppressed proinflammatory cytokines in PBMCs, maturation of monocyte-derived dendritic cells (rendering their profile to regulatory phenotype), and antigen-specific proliferation in vitro . Conclusion Our data demonstrate an essential role for IL-10 in inducing an immunoregulatory phenotype in B cells that exerts substantial anti-inflammatory and immunosuppressive functions.

Background: IL 10 producing regulatory B cells suppress immune responses and lack of these cells leads to exacerbated symptoms in mouse models of chronic inflammation transplantation and chronic infection. IgG4 is a blocking antibody isotype with anti inflammatory potential that is induced in human high dose antigen tolerance models. Objective: We sought to characterize human inducible IL 10 secreting B regulatory 1 (BR1) cells and to investigate their immunoregulatory capacity through suppression of cellular immune responses and production of anti inflammatory immunoglobulins. Methods: Highly purified IL 10 secreting B cells were phenotypically and functionally characterized by means of whole genome expression analysis flow cytometry suppression assay and antibody production. B cells specific for the major bee venom allergen phospholipase A2 (PLA) were isolated from beekeepers who displayed tolerance to bee venom antigens and allergic patients before and after specific immunotherapy. Results: Human IL 10+ BR1 cells expressed high surface CD25 and CD71 and low CD73 levels. Sorting of CD73 CD25+CD71+ B cells allowed enrichment of human BR1 cells which produced high levels of IL 10 and potently suppressed antigen specific CD4+ T cell proliferation. IgG 4 was selectively confined to human BR1 cells. B cells specific for the major bee venom allergen PLA isolated from nonallergic beekeepers show increased expression of IL 10 and IgG4. Furthermore the frequency of IL 10+ PLA specific B cells increased in allergic patients receiving allergen specific immunotherapy. Conclusion: Our data show the characterization of IL 10+ BR1 cells and in vivo evidence for 2 essential features of allergen tolerance: the suppressive B cells and IgG4 expressing B cells that are confined to IL 10+ BR1 cells in human subjects. © 2013 American Academy of Allergy Asthma Immunology.

T cells are involved in the pathogenesis of many diseases. To exert a pathological effect, T cells enter the tissues. We show that the determination of their entry site requires isolation of the respective T cell population, injection into genetically un-manipulated animals, and identification of the cells in vivo at various time points after injection. We indicate variables influencing in vivo migration experiments artificially, and outline how resulting problems can be either avoided or taken into account. Reviewing experiments performed according to the outlined criteria reveals two types of migration patterns for T cell subsets in vivo: 1). Naive and memory T cells enter lymphoid and non-lymphoid organs in comparable numbers, but selectively accumulate in lymphoid tissues over time, 2). Effector T cells, too, enter lymphoid and non-lymphoid organs in comparable numbers. However, most of them die within 24 hours. Depending on the presence of cytokines, chemokines and extracellular matrix compounds they are able to survive, thereby preferentially accumulating in their target tissues. This information might help to understand the role of migration in the pathogenesis of T cell mediated diseases.