Antigen Presentation and Immune Regulation Research Group (AIR)
Dr. Christopher Schliehe was recruited by the Erasmus MC in 2016 and is currently Assistant Professor in the Department of Immunology. After his doctoral studies at the University of Konstanz, Germany, in which he studied the principles of antigen presentation, he moved to CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences in Vienna, Austria, and investigated mechanisms of immune regulation by epigenetic modifiers as a postdoctoral fellow.
Christopher´s team is embedded in the Department of Immunology and has a focus on antigen presentation and immune regulation in the context of immunotherapies. It combines a large spectrum of experimental approaches (including classical immunological techniques, in vivo models, genetic screens, mass spectrometry, and chemical immunology) to elucidate the molecular mechanisms and regulatory processes involved in antigen presentation on MHC class I molecules as well as innate and adaptive immune activation.
The adaptive immune system efficiently clears pathogens by inducing antigen-specific responses. The antigen receptors of T-cells recognize short polypeptides presented on molecules of the major histocompatibility complex (MHC). Two classes of MHC presentation have been described. The majority of cell types is able to present intracellular antigens on MHC class I, which is recognized by CD8+ cytotoxic T-cells (CTLs). This pathway is referred to as the direct presentation pathway and it reflects a mechanism of immune surveillance to fight intracellular pathogens and cancer. Antigen presentation by MHC class II, in contrast, can only be performed by specialized cell types, so-called professional antigen presenting cells (APCs), including dendritic cells and macrophages. MHC class II presentation is usually restricted to extracellular antigens and is recognized by CD4+ T-helper-cells that are important for immune regulation and activation of B-cell responses. To be fully functional, both CD8+ and CD4+ T-cells need a step of initial activation, called T-cell priming, which requires MHC presentation on activated APCs. This activation occurs via pattern recognition receptors (PRRs) that sense pathogen- and danger-associated molecules. The priming of CTL responses against tissue-specific antigens, which cannot be directly presented by APCs, requires an alternative pathway of MHC class I presentation, referred to as cross-presentation. This term describes the MHC class I presentation of exogenous antigens by professional APCs. Cross-presentation is the exclusive pathway by which CTLs can be primed against epitopes derived from cancer antigens or tissue-specific autoantigens.
Enhancing MHC class I presentation by bifunctional degraders (PROTACs):
Bifunctional degraders, also referred to as proteolysis-targeting chimeras (PROTACs), are a recently developed class of small molecules. They were designed to specifically target endogenous proteins for ubiquitin/proteasome-dependent degradation and to thereby interfere with pathological mechanisms of diseases, including cancer. For one of our research projects, we hypothesized that this process of acute pharmacologic protein degradation might increase the direct MHC class I presentation of degraded targets. By studying this question, we contribute to the discussion about the origin of peptides feeding the MHC class I presentation pathway. Two scenarios have been postulated: peptides can either be derived from homeostatic turnover of mature proteins and/or from short- lived defective ribosomal products (DRiPs), but currently, it is still unclear to what ratio and efficiency both pathways contribute to the overall MHC class I presentation. We therefore generated the intrinsically stable model antigen GFP-S8L-F12 that was susceptible to acute pharmacologic degradation via the previously described degradation tag (dTAG) system. Using different murine cell lines, we could show that the bifunctional molecule dTAG-7 induced rapid proteasome-dependent degradation of GFP-S8L-F12 and simultaneously increased its direct presentation on MHC class I molecules. These experiments were, to our knowledge, the first to investigate targeted pharmacologic protein degradation in the context of antigen presentation and our data point toward future applications by strategically combining therapies using bifunctional degraders with their stimulating effect on direct MHC class I presentation. Currently we aim to translate your findings into clinically relevant models of cancer.
Figure 1. dTAG-7 induces degradation of a model antigen. (A) The model antigens GFP-S8L-F12 (1) and ΔFKBP12 (2). (B) Illustration of dTAG-7-mediated antigen degradation. (C, D) GFP-S8L-F12 or ΔFKBP12 expressing BMC-2 cells were cultured with increasing concentrations of dTAG-7 or 0.1% DMSO as control (0µM) for 18 hours and GFP-specific fluorescence was quantified by flow cytometry. (C) Representative histograms comparing GFP-specific fluorescence with or without 1µM dTAG-7 treatment to wildtype BMC-2 cells (WT). (D) The graph indicates % residual GFP-specific fluorescence normalized to the mean fluorescence intensity (MFI) of an untreated control (mean ±SD from triplicates). Representative results from 3 independent experiments are shown.
Figure 2. Degradation tag (dTAG)-7-induced antigen degradation increases its MHC class I presentation. (a) GFP-S8L-F12-expressing BMC-2 cells were treated with 1 μM dTAG-7 for indicated times. GFP-specific fluorescence (MFI-GFP) and MHC class I presentation of antigen-derived S8L (MFI-H-2Kb/S8L) was detected by flow cytometry. MFI, mean fluorescence intensity. (B) BMC-2 cells expressing ΔFKBP12 were treated for 2 h with 1 μM dTAG-7 or left untreated as control and MFI-GFP as well as MFI-H-2Kb/S8L were measured by flow cytometry as described above. (C,D) GFP-S8L-F12-expressing DC2.4 (C) and MC57G (D) cells were treated and analyzed as described in (A). All experiments were performed in triplicates and results are shown as mean ± SEM. Representative results from three independent experiments are shown.
Additional lines of Investigation:
1) We perform unbiased genetic screens to identify novel mechanisms involved in MHC class I presentation. This research aims at improving our fundamental understanding of antigen presentation pathways and to identify novel protein targets for immunotherapy.
2) We investigate the role of intracellular vesicle transport in the cross-presentation of soluble, particular, and cell-associated antigens. With this research, we aim to contribute to the improvement of CTLs vaccines against cancer and other diseases, which requires a fundamental understanding of the underlying mechanisms of cross-presentation.
3) We investigate how post-translational modification of proteins influence the course of immune responses. Combining mass spectrometry-based analyses with classic biochemical assays, we aim to identify novel drug targets for the fine-tuning of immune responses by small molecules.
- Christopher Schliehe, Group leader
- Jane Voerman, Research Assistant (since 2016)
- Gunja Mishra, Postdoc (since 2019)
- Emma Tondeur, PhD student (since 2019)
- Ziye Song, PhD student (since 2019)
- Anoek Huijsmans, MSc Student Infection and Immunity (since 2020)
- Izge Shanlitourk, MSc Student Molecular Medicine (since 2020)
- Laure van Hofwegen, MSc Student Infection and Immunity (2019-2020)
- Anneloes van Krimpen, MSc Student Infection and Immunity (2019)
- Daryl Geers, MSc Student Infection and Immunity (since 2019)
- Roos Klop, Research Assistant (2018)
- Tim Breugem, MSc Student Infection and Immunity (2017-2018)
- Anne Rodenburg, MSc Student Molecular Medicine (2017-2018)
- Max Lee, MSc Student Molecular Medicine (2016-2017)
- Sarah Moser, MSc Student Molecular Medicine (2016-2017)
(See for all publications Schliehe C in PubMed)
Goncalves-Alves E, Saferding V, Schliehe C., Benson R, Kurowska-Stolarska M, Brunner JS, Puchner A, Podesser BK, Smolen J.S, Redlich K, Bonelli M, Brewer J, Bergthaler A, Steiner G, and Bluml S.
MicroRNA-155 Controls T Helper Cell Activation During Viral Infection.
Frontiers in Immunology 2019, 10:1664, DOI: 10.3389/fimmu.2019.01367
Moser SC, Voerman JSA, Buckley DL, Winter GE and Schliehe C.
Acute Pharmacologic Degradation of a Stable Antigen Enhances its Direct Presentation on MHC Class I Molecules.
Frontiers in Immunology 2018, 8:1920. doi: 10.3389/fimmu.2017.01920.
Khamina K, Lercher A, Caldera M, Schliehe C, Vilagos B, Sahin M, Kosack L, Bhattacharya A, Májek P, Stukalov A, Sacco R, James LC, Pinschewer DD, Bennett KL, Menche J., Bergthaler A.
Characterization of host proteins interacting with the lymphocytic choriomeningitis virus L protein.
PLoS Pathogens. 2017 Dec 20;13(12):e1006758. doi: 10.1371/journal.ppat.1006758. eCollection 2017 Dec.
Kosack L, Gawish R, Lercher A, Vilagos B, Hladik A, Lakovits K, Bhattacharya A, Schliehe C, Mesteri I, Knapp S, and Bergthaler A.
The lipid-sensor TREM2 aggravates disease in a model of LCMV-induced hepatitis.
Scientific Reports 2017, 7: 11289.
Bhattacharya A, Hegazy AN, Deigendesch N, Kosack L, Cupovic J, Kandasamy RK, Hildebrandt A, Merkler D, Kühl AA, Vilagos B, Schliehe C, Panse I, Khamina K, Baazim H, Arnold I, Flatz L, Xu H.C, Lang PA, Aderem A, Takaoka A, Superti-Furga G, Colinge J, Ludewig B, Löhning M, Bergthaler A.
Superoxide Dismutase 1 Protects Hepatocytes from Type I Interferon-Driven Oxidative Damage.
Immunity. 2015 Nov 17;43(5):974-86.
Schliehe C, Flynn EK, Vilagos B, Richson U, Swaminathan S, Bosnjak B, Bauer L, Kandasamy RK, Griesshammer IM, Kosack L, Schmitz F, Litvak V, Sissons J, Lercher A, Bhattacharya A, Khamina K, Trivett AL, Tessarollo L, Mesteri I, Hladik A, Merkler D, Kubicek S, Knapp S, Epstein MM, Symer DE, Aderem A, Bergthaler A.
The methyltransferase Setdb2 mediates virus-induced susceptibility to bacterial superinfection.
Nature Immunology. 2015 Jan;16(1):67-74.
Schliehe C, Bitzer A, van den Broek M, Groettrup M.
Stable antigen is most effective for eliciting CD8+ T-cell responses after DNA vaccination and infection with recombinant vaccinia virus in vivo.
Journal of Virology. 2012 Sep;86(18):9782-93.
Schliehe C, Redaelli C, Engelhardt S, Fehlings M, Mueller M, van Rooijen N, Thiry M, Hildner K, Weller H, Groettrup M.
CD8- dendritic cells and macrophages cross-present poly(D,L-lactate-co-glycolate) acid microsphere-encapsulated antigen in vivo.
Journal of Immunology. 2011 Sep 1;187(5):2112-21.
Schliehe C, Schliehe C, Thiry M, Tromsdorf UI, Hentschel J, Weller H, Groettrup M.
Microencapsulation of inorganic nanocrystals into PLGA microsphere vaccines enables their intracellular localization in dendritic cells by electron and fluorescence microscopy.
Journal of Controlled Release. 2011 May 10;151(3):278-85.