Tumor-Derived Microvesicles Induce, Expand and Up-Regulate Biological Activities of Human Regulatory T Cells (Treg)

Background: Tumor-derived microvesicles (TMV) or exosomes are present in body fluids of patients with cancer and might be involved in tumor progression. The frequency and suppressor functions of peripheral blood CD4 + CD25 high FOXP3 + Treg are higher in patients with cancer than normal controls. The hypothesis is tested that TMV contribute to induction/ expansion/and activation of human Treg. Methodology/Principal Findings: TMV isolated from supernatants of tumor cells but not normal cells induced the generation and enhanced expansion of human Treg. TMV also mediated conversion of CD4 + CD25 neg T cells into CD4 + CD25 high FOXP3 + Treg. Upon co-incubation with TMV, Treg showed an increased FasL, IL-10, TGF-b1, CTLA-4, granzyme B and perforin expression (p,0.05) and mediated stronger suppression of responder cell (RC) proliferation (p,0.01). Purified Treg were resistant to TMV-mediated apoptosis relative to other T cells. TMV also increased phospho-SMAD2/3 and phospho-STAT3 expression in Treg. Neutralizing Abs specific for TGF-b1 and/or IL-10 significantly inhibited TMV ability to expand Treg. Conclusions/Significance: This study suggests that TMV have immunoregulatory properties. They induce Treg, promote Treg expansion, up-regulate Treg suppressor function and enhance Treg resistance to apoptosis. Interactions of TMV wit

Immunomodulatory role of Keratin 76 in oral and gastric cancer

Keratin 76 (Krt76) is an epithelial differentiation marker that is downregulated in oral squamous cell carcinomas, correlating with poor prognosis. Here the authors show that genetic ablation of Krt76 in a mouse model results in increased susceptibility to carcinogenesis via enhanced accumulation of Tregs

Decreased Numbers of Blood Dendritic Cells and Defective Function of Regulatory T Cells in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

BACKGROUND: Dendritic cells (DC) and regulatory cells (Treg) play pivotal roles in controlling both normal and autoimmune adaptive immune responses. DC are the main antigen-presenting cells to T cells, and they also control Treg functions. In this study, we examined the frequency and phenotype of DC subsets, and the frequency and function of Treg from patients with ANCA-associated vasculitis (AAV). METHODOLOGY/PRINCIPAL FINDINGS: Blood samples from 19 untreated patients with AAV during flares and before any immunosuppressive treatment were analyzed, along with 15 AAV patients in remission and 18 age-matched healthy controls. DC and Treg numbers, and phenotypes were assessed by flow cytometry, and in vitro suppressive function of Treg was determined by co-culture assay. When compared to healthy volunteers, absolute numbers of conventional and plasmacytoid DC were decreased in AAV patients. During the acute phase this decrease was significantly more pronounced and was associated with an increased DC expression of CD62L. Absolute numbers of Treg (CD4(+)CD25(high)CD127(low/-) Tcells) were moderately decreased in patients. FOXP3 and CD39 were expressed at similar levels on Treg from patients as compared to controls. The suppressive function of Treg from AAV patients was dramatically decreased as compared to controls, and this defect was more pronounced during flares than remission. This Treg functional deficiency occurred in the absence of obvious Th17 deviation. CONCLUSION: In conclusion, these data show that AAV flares are associated with both a decrease number and altered phenotype of circulating DC and point to a role for Treg functional deficiency in the pathogenesis of AAV

Purinergic signalling and immune cells

This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

Transorale Chirurgie im Bereich der Supraglottis mit dem Medrobotics FLEX System

Michael Collins' and Sharland's ERF tractor - registration CYK542C - photographed 25 July 1982

Transorale Chirurgie im Bereich der Supraglottis mit dem Medrobotics FLEX System

Einleitung: Die transorale Resektion supraglottischer Tumore ist aufgrund der Lokalisation im engen anatomischen Raum anspruchsvoll. In dieser Studie wird die Visualisierung und Resektion im Bereich der Supraglottis mittels eines neuartigen flexiblen Computer-assistierten Endoskopsystems evaluiert. Material und Methoden: Das Medrobotics Flex System ist ein einarmiges, Endoskopsystem, das mit 3,5 mm flexiblen Instrumenten ausgestattet ist. An sechs Leichen wurde durch zwei Operateure eine Taschenbandresektion bilateral durchgeführt. Die Positionierungs- und Resektionsdauer wurden für jeden Eingriff bestimmt. Ergebnisse: Eine adäquate Exposition wurde in allen Fällen erreicht, eine Resektion der Taschenfalten in allen Fällen möglich. Die durchschnittliche Dauer zur transoralen Positionierung des Endoskops betrug 3,8 ± 1,9 min, die durchschnittliche Operationsdauer betrug 8,9 ± 4 min. Bei beiden Operateuren zeigte sich eine steile Lernkurve in der Anwendung des Systems.Schlussfolgerung: Mittels des Medrobotics Flex System ist eine transorale Resektion im Bereich der Supraglottis durchführbar. Die gute Visualisierung und Resektabilität stellen Vorteile des Systems dar.Der Erstautor gibt keinen Interessenkonflikt an