TY  - THES
A1  - Riedel, Alexander
T1  - Untersuchungen zur endogenen MHC-Klasse-II-restringierten Präsentation nukleärer Antigene
T1  - Investigation of the endogenous MHC class II-restricted presentation of nuclear antigens
N2  - Die endogene Präsentation von intrazellulären Antigenen auf Major-Histokompatibilitätskomplex Klasse-II (MHC-II) -Molekülen ist von entscheidender Bedeutung für eine Reihe von immunologischen Prozessen. Die mechanistischen Grundlagen dieses Präsentationsweges sind aber noch weitgehend unverstanden. Ziel dieser Arbeit war es, einen Beitrag zum molekularen Verständnis der Abläufe zu leisten, die an der endogenen Präsentation nukleärer Antigene auf MHC-II-Molekülen beteiligt sind. Dazu sollte am Beispiel des nukleär lokalisierten Modellantigens Neomycin-Phosphotransferase II (NucNeoR) sowie des viralen Kernantigens Epstein-Barr-virus nuclear antigen 3C (EBNA3C) und entsprechender antigenspezifischer MHC-II-restringierter CD4+ T-Zellen die verantwortlichen Präsentationswege in professionell und nicht-professionell antigenpräsentierenden Zellen untersucht werden. In beiden Zellsystemen wurde NucNeoR über einen endogenen Präsentationsweg und nicht über die Freisetzung und Wiederaufnahme als exogenes Protein auf MHC-II-Molekülen präsentiert. Durch die Verwendung chemischer Inhibitoren konnte eine Beteiligung der Autophagie an der endogenen Antigenpräsentation nachgewiesen werden. Da Autophagie ausschließlich im Zytoplasma stattfindet, wurde nach möglichen Eintrittspforten für nukleäre Proteine in diesen Abbauweg gesucht. Für die Autophagie-abhängige Präsentation von NucNeoR war weder ein CRM1-vermittelter aktiver Export des Antigens aus dem Kern ins Zytoplasma, noch eine Auflösung der Kernmembran im Rahmen der Zellteilung und der dadurch bedingten Durchmischung nukleärer und zytoplasmatischer Bestandteile notwendig. Mit Hilfe eines konditionalen Antigenexpressionsystems und der Auftrennung antigenexprimierender Zellen nach Zellzyklusphasen konnte eine verstärkte Antigenpräsentation in der G1/0-Phase nachgewiesen werden, die mit fortschreitendem Zellzyklus immer mehr abnahm. Die Antigenpräsentation korrelierte dabei mit der ebenfalls im Laufe des Zellzyklus abnehmenden Transkriptions- bzw. Translationsrate des Antigens, aber nicht mit der absoluten Menge an Antigen in den Zellen. Bei abgeschalteter Antigentranskription dagegen korrelierte die Antigenpräsentation mit der MHC-II-Oberflächenexpression, die von der G1/0- bis hin zur G2/M-Phase kontinuierlich zunahm. Eine ähnliche Korrelation von Antigentranskription/ Antigentranslation und Autophagie-abhängiger Antigenpräsentation wurde auch für EBNA3C und die zytoplasmatisch lokalisierte NeoR-Variante beobachtet. Diese Ergebnisse identifizieren die Autophagie-abhängige Präsentation neusynthetisierter Proteine als den verantwortlichen molekularen Mechanismus für die endogene Präsentation der untersuchten nukleären Antigene auf MHC-II-Molekülen. Durch die Kopplung von Translation und autophagischem Abbau erlangen Proteine unabhängig von ihrer subzellulären Lokalisation Zugang zu diesem Präsentationsweg und erweitern so das Spektrum der intrazellulären Antigene, die einer CD4+ T-Zellüberwachung unterliegen.
N2  - The endogenous presentation of intracellular antigens on major histocompatibility complex class II (MHC-II) molecules plays an important role in adaptive immune responses, but the underlying molecular mechanisms are not well understood. The aim of this study was to gain insight into the endogenous presentation pathways for nuclear antigens on MHC-II molecules. By using antigen-specific CD4+ T cell clones, MHC-II presentation of the nuclear antigens neomycin phosphotransferase II (NucNeoR) and Epstein-Barr virus nuclear antigen 3C (EBNA3C) was studied in professional and non-professional antigen presenting cells (APC). Both types of APC presented peptides derived from these nuclear proteins on MHC-II molecules by an endogenous presentation pathway and not by release and reuptake as exogenous protein. Inhibition of autophagy drastically reduced endogenous antigen presentation, indicating that nuclear proteins enter the MHC-II processing and loading compartment through autophagic vesicles. Because autophagocytosis occurs in the cytoplasm, potential entry routes for nuclear proteins into this pathway were investigated. Endogenous presentation of NucNeoR on MHC-II molecules by autophagy did neither involve the CRM1-mediated export of the nuclear protein into the cytoplasm, nor the redistribution of nuclear and cytoplasmic components following the dissolution of the nuclear envelope during mitosis. Conditional antigen expression and cell cycle phase separation of antigen-expressing cells revealed that antigen presentation was maximal in cells in G1/0 and then gradually decreased as cells progressed in the cell cycle. This reduction in antigen presentation correlated with a cell cycle-dependent decrease in antigen transcription/translation, but not with the total amount of antigen present in these cells. By contrast, when antigen expression was turned off, antigen presentation correlated with MHC-II surface expression, which increased from G1/0- to G2/M-phase. A similar correlation between antigen presentation and antigen transcription/translation was also observed for the antigens EBNA3C and the cytosolic variant of neomycin phosphotransferase II (NeoR). These results identify autophagocytosis of newly-synthesized proteins as the molecular mechanism mediating endogenous presentation of nuclear and cytosolic antigens on MHC-II molecules. By coupling protein translation and autophagocytosis, newly-synthesized proteins gain access to the endogenous MHC-II presentation pathway irrespective of their subcellular localisation and thereby broaden the spectrum of intracellular antigens that are presented to CD4+ T cells.
KW  - Autophagie
KW  - Antigenpräsentation
KW  - MHC
KW  - nukleäre Antigene
KW  - T-Zellen
KW  - autophagy
KW  - antigen presentation
KW  - MHC
KW  - nuclear antigen
KW  - T Lymphocytes
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-25183
ER  - 
TY  - JOUR
A1  - Dumont, Martine
A1  - Weber-Lassalle, Nana
A1  - Joly-Beauparlant, Charles
A1  - Ernst, Corinna
A1  - Droit, Arnaud
A1  - Feng, Bing-Jian
A1  - Dubois, Stéphane
A1  - Collin-Deschesnes, Annie-Claude
A1  - Soucy, Penny
A1  - Vallée, Maxime
A1  - Fournier, Frédéric
A1  - Lemaçon, Audrey
A1  - Adank, Muriel A.
A1  - Allen, Jamie
A1  - Altmüller, Janine
A1  - Arnold, Norbert
A1  - Ausems, Margreet G. E. M.
A1  - Berutti, Riccardo
A1  - Bolla, Manjeet K.
A1  - Bull, Shelley
A1  - Carvalho, Sara
A1  - Cornelissen, Sten
A1  - Dufault, Michael R.
A1  - Dunning, Alison M.
A1  - Engel, Christoph
A1  - Gehrig, Andrea
A1  - Geurts-Giele, Willemina R. R.
A1  - Gieger, Christian
A1  - Green, Jessica
A1  - Hackmann, Karl
A1  - Helmy, Mohamed
A1  - Hentschel, Julia
A1  - Hogervorst, Frans B. L.
A1  - Hollestelle, Antoinette
A1  - Hooning, Maartje J.
A1  - Horváth, Judit
A1  - Ikram, M. Arfan
A1  - Kaulfuß, Silke
A1  - Keeman, Renske
A1  - Kuang, Da
A1  - Luccarini, Craig
A1  - Maier, Wolfgang
A1  - Martens, John W. M.
A1  - Niederacher, Dieter
A1  - Nürnberg, Peter
A1  - Ott, Claus-Eric
A1  - Peters, Annette
A1  - Pharoah, Paul D. P.
A1  - Ramirez, Alfredo
A1  - Ramser, Juliane
A1  - Riedel-Heller, Steffi
A1  - Schmidt, Gunnar
A1  - Shah, Mitul
A1  - Scherer, Martin
A1  - Stäbler, Antje
A1  - Strom, Tim M.
A1  - Sutter, Christian
A1  - Thiele, Holger
A1  - van Asperen, Christi J.
A1  - van der Kolk, Lizet
A1  - van der Luijt, Rob B.
A1  - Volk, Alexander E.
A1  - Wagner, Michael
A1  - Waisfisz, Quinten
A1  - Wang, Qin
A1  - Wang-Gohrke, Shan
A1  - Weber, Bernhard H. F.
A1  - Devilee, Peter
A1  - Tavtigian, Sean
A1  - Bader, Gary D.
A1  - Meindl, Alfons
A1  - Goldgar, David E.
A1  - Andrulis, Irene L.
A1  - Schmutzler, Rita K.
A1  - Easton, Douglas F.
A1  - Schmidt, Marjanka K.
A1  - Hahnen, Eric
A1  - Simard, Jacques
T1  - Uncovering the contribution of moderate-penetrance susceptibility genes to breast cancer by whole-exome sequencing and targeted enrichment sequencing of candidate genes in women of European ancestry
JF  - Cancers
N2  - Rare variants in at least 10 genes, including BRCA1, BRCA2, PALB2, ATM, and CHEK2, are associated with increased risk of breast cancer; however, these variants, in combination with common variants identified through genome-wide association studies, explain only a fraction of the familial aggregation of the disease. To identify further susceptibility genes, we performed a two-stage whole-exome sequencing study. In the discovery stage, samples from 1528 breast cancer cases enriched for breast cancer susceptibility and 3733 geographically matched unaffected controls were sequenced. Using five different filtering and gene prioritization strategies, 198 genes were selected for further validation. These genes, and a panel of 32 known or suspected breast cancer susceptibility genes, were assessed in a validation set of 6211 cases and 6019 controls for their association with risk of breast cancer overall, and by estrogen receptor (ER) disease subtypes, using gene burden tests applied to loss-of-function and rare missense variants. Twenty genes showed nominal evidence of association (p-value < 0.05) with either overall or subtype-specific breast cancer. Our study had the statistical power to detect susceptibility genes with effect sizes similar to ATM, CHEK2, and PALB2, however, it was underpowered to identify genes in which susceptibility variants are rarer or confer smaller effect sizes. Larger sample sizes would be required in order to identify such genes.
KW  - breast cancer
KW  - genetic susceptibility
KW  - whole-exome sequencing
KW  - moderate-penetrance genes
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281768
SN  - 2072-6694
VL  - 14
IS  - 14
ER  - 
TY  - JOUR
A1  - Haake, Markus
A1  - Haack, Beatrice
A1  - Schäfer, Tina
A1  - Harter, Patrick N.
A1  - Mattavelli, Greta
A1  - Eiring, Patrick
A1  - Vashist, Neha
A1  - Wedekink, Florian
A1  - Genssler, Sabrina
A1  - Fischer, Birgitt
A1  - Dahlhoff, Julia
A1  - Mokhtari, Fatemeh
A1  - Kuzkina, Anastasia
A1  - Welters, Marij J. P.
A1  - Benz, Tamara M.
A1  - Sorger, Lena
A1  - Thiemann, Vincent
A1  - Almanzar, Giovanni
A1  - Selle, Martina
A1  - Thein, Klara
A1  - Späth, Jacob
A1  - Gonzalez, Maria Cecilia
A1  - Reitinger, Carmen
A1  - Ipsen-Escobedo, Andrea
A1  - Wistuba-Hamprecht, Kilian
A1  - Eichler, Kristin
A1  - Filipski, Katharina
A1  - Zeiner, Pia S.
A1  - Beschorner, Rudi
A1  - Goedemans, Renske
A1  - Gogolla, Falk Hagen
A1  - Hackl, Hubert
A1  - Rooswinkel, Rogier W.
A1  - Thiem, Alexander
A1  - Romer Roche, Paula
A1  - Joshi, Hemant
A1  - Pühringer, Dirk
A1  - Wöckel, Achim
A1  - Diessner, Joachim E.
A1  - Rüdiger, Manfred
A1  - Leo, Eugen
A1  - Cheng, Phil F.
A1  - Levesque, Mitchell P.
A1  - Goebeler, Matthias
A1  - Sauer, Markus
A1  - Nimmerjahn, Falk
A1  - Schuberth-Wagner, Christine
A1  - Felten, Stefanie von
A1  - Mittelbronn, Michel
A1  - Mehling, Matthias
A1  - Beilhack, Andreas
A1  - van der Burg, Sjoerd H.
A1  - Riedel, Angela
A1  - Weide, Benjamin
A1  - Dummer, Reinhard
A1  - Wischhusen, Jörg
T1  - Tumor-derived GDF-15 blocks LFA-1 dependent T cell recruitment and suppresses responses to anti-PD-1 treatment
JF  - Nature Communications
N2  - Immune checkpoint blockade therapy is beneficial and even curative for some cancer patients. However, the majority don’t respond to immune therapy. Across different tumor types, pre-existing T cell infiltrates predict response to checkpoint-based immunotherapy. Based on in vitro pharmacological studies, mouse models and analyses of human melanoma patients, we show that the cytokine GDF-15 impairs LFA-1/β2-integrin-mediated adhesion of T cells to activated endothelial cells, which is a pre-requisite of T cell extravasation. In melanoma patients, GDF-15 serum levels strongly correlate with failure of PD-1-based immune checkpoint blockade therapy. Neutralization of GDF-15 improves both T cell trafficking and therapy efficiency in murine tumor models. Thus GDF-15, beside its known role in cancer-related anorexia and cachexia, emerges as a regulator of T cell extravasation into the tumor microenvironment, which provides an even stronger rationale for therapeutic anti-GDF-15 antibody development.
KW  - cancer microenvironment
KW  - immunotherapy
KW  - T cells
KW  - tumour immunology
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357333
VL  - 14
ER  -