Robert Thimme

Universitätsklinikum Freiburg, Freiburg an der Elbe, Lower Saxony, Germany

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Publications (220)1033.73 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Virus-specific CD8(+) T cells are rarely detectable ex vivo by conventional methods during chronic hepatitis C virus (HCV) infection. In this study, however, we were able to detect and characterize HCV-specific CD8(+) T cells in all chronically genotype 1a infected, HLA-A*02:01(+) patients analyzed by performing major histocompatibility complex (MHC) class I tetramer enrichment. Two thirds of these enriched HCV-specific CD8(+) T-cell populations displayed an effector-memory phenotype whereas, surprisingly, one third displayed a naïve-like phenotype despite ongoing viral replication. CD8(+) T cells with an effector-memory phenotype could not expand in vitro, suggesting exhaustion of these cells. Interestingly, some of the naïve-like CD8(+) T cells proliferated vigorously upon in vitro priming, whereas others did not. These differences were linked to the corresponding viral sequences in the respective patients. Indeed, naïve-like CD8(+) T cells from patients with consensus sequence in the corresponding T-cell epitope did not expand in vitro. In contrast, in patients displaying sequence variations, we were able to induce HCV-specific CD8(+) T-cell proliferation, which may indicate infection with a variant virus. Collectively, these data reveal the presence of phenotypically and functionally diverse HCV-specific CD8(+) T cells at very low frequencies that are detectable in all chronically infected patients despite viral persistence.
    Journal of virology. 10/2014;
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    ABSTRACT: Skewed T helper (TH) cell responses and specific functions of TH1, TH2, TH17, and Treg cells have been implicated in the pathogenesis of inflammatory bowel disease (IBD) that led to the establishment of the pathogenic TH1/TH2 and TH17/Treg cell imbalance paradigms. However, the relevant TH cell population driving mucosal inflammation is still unknown.
    Inflammatory Bowel Diseases 09/2014; · 5.12 Impact Factor
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    ABSTRACT: The transcription factor T-bet regulates the production of interferon-γ and cytotoxic molecules in effector CD8 T cells, and its expression correlates with improved control of chronic viral infections. However, the role of T-bet in infections with differential outcome remains poorly defined. Here, we report that high expression of T-bet in virus-specific CD8 T cells during acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection was associated with spontaneous resolution, whereas T-bet deficiency was more characteristic of chronic evolving infection. T-bet strongly correlated with interferon-γ production and proliferation of virus-specific CD8 T cells, and its induction by antigen and IL-2 stimulation partially restored functionality in previously dysfunctional T-bet-deficient CD8 T cells. However, restoration of a strong interferon-γ response required additional stimulation with IL-12, which selectively induced the phosphorylation of STAT4 in T-bet(+) CD8 T cells. The observation that T-bet expression rendered CD8 T cells responsive to IL-12 suggests a stepwise mechanism of T cell activation in which T-bet facilitates the recruitment of additional transcription factors in the presence of key cytokines. These findings support a critical role of T-bet for viral clearance and suggest T-bet deficiency as an important mechanism behind chronic infection.
    The Journal of experimental medicine. 09/2014;
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    ABSTRACT: Acute graft-versus-host disease (GvHD) limits the success of allogeneic hematopoietic cell transplantation (allo-HCT), therefore a better understanding of its biology may improve therapeutic options. We observed miR-146a upregulation in T cells of mice developing acute GvHD compared to untreated mice. Transplanting miR-146a(-/-) T cells caused increased GvHD severity, elevated TNF serum levels and reduced survival. TNF receptor-associated factor 6(TRAF6), a verified target of miR-146a, was upregulated in miR-146a(-/-) T cells following alloantigen stimulation. Higher TRAF6 levels translated into increased NF-κB activity and TNF production in miR-146a(-/-) T cells. Conversely, the detrimental effect of miR-146a deficiency in T cells was antagonized by TNF blockade, while phytochemical induction of miR-146a or its overexpression using a miR-146a mimic reduced GvHD severity. In humans, the minor genotype of the SNP rs2910164 in HCT donors, which reduces expression of miR-146a, was associated with severe acute GvHD (grade III/IV). We show that miR-146a functions as a negative regulator of donor T cells in GvHD by targeting TRAF6, leading to reduced TNF transcription. Since miR-146a expression can be exogenously enhanced, our results provide a novel, targeted molecular approach to mitigate GvHD.
    Blood 09/2014; · 9.78 Impact Factor
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    Annals of Hematology 07/2014; · 2.87 Impact Factor
  • Bertram Bengsch, Bianca Martin, Robert Thimme
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    ABSTRACT: The up-regulation of several inhibitory signalling pathways by exhausted HBV-specific CD8+ T-cells in chronic infection is thought to contribute to viral persistence. Blockade of inhibitory receptors to reinvigorate exhausted T-cell function is a promising novel therapeutic approach. However, little information is available regarding the relative contribution of individual inhibitory pathways to HBV-specific CD8+ T-cell failure and the impact of inhibitory receptor blockade on restoration of T-cell function in chronic HBV.
    Journal of Hepatology 07/2014; · 9.86 Impact Factor
  • Gut 06/2014; · 10.73 Impact Factor
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    ABSTRACT: Accumulation of CD3+TCRαβ+CD4-CD8- double negative T (DNT) cells is a hallmark of autoimmune lymphoproliferative syndrome (ALPS). DNT origin and differentiation pathways remain controversial. Here we show that human ALPS DNT have features of terminally differentiated effector memory CD45RA+ (TEMRA) cells, but are CD27+CD28+KLRG1- and do not express the transcription factor T-bet. This unique phenotype was also detected among CD4+ or CD8+ ALPS TEMRA cells. TCRβ deep sequencing revealed a significant fraction of shared CDR3 sequences between ALPS DNT and both CD4+ and CD8+TEMRA cells. Moreover, in ALPS patients with a germline FAS mutation and somatic loss of heterozygosity, in whom biallelic mutant cells can be tracked by absent Fas expression, Fas negative T-cells accumulated not only among DNT, but also among CD4+ and CD8+TEMRA cells. These data indicate that in human Fas deficiency DNT can not only derive from CD8+, but also from CD4+ T-cells. Furthermore, defective Fas signalling leads to aberrant transcriptional programs and differentiation of subsets of CD4+ and CD8+ T-cells. Accumulation of these cells before their double negative state appears to be an important early event in the pathogenesis of lymphoproliferation in ALPS patients.
    Blood 06/2014; · 9.78 Impact Factor
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    ABSTRACT: Chronic hepatitis C virus (HCV) infection is characterized by a failure of virus-specific CD8+ T cells that is mainly caused by viral escape and T-cell exhaustion. Constant antigen stimulation has been suggested to contribute to HCV-specific CD8+ T-cell exhaustion. However, IFN-based therapies failed to recover HCV-specific CD8+ T-cell function suggesting that the damage to CD8+ T cells may be permanent even after antigen removal. It was therefore the objective of this study to analyze the impact of inhibition of ongoing viral replication by IFN-free therapy with direct acting antivirals (DAA) on the phenotype and function of HCV-specific CD8+ T cells.
    Journal of Hepatology 06/2014; · 9.86 Impact Factor
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    Percy A Knolle, Robert Thimme
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    ABSTRACT: The liver is an organ with unique immune regulatory functions favoring the induction of immune tolerance rather than immunity. These functions are mediated by local expression of co-inhibitory receptors and immunosuppressive mediators that help to prevent overwhelming tissue damage. Over the past years we have gained more insight into the local regulatory cues that determine the functional complexity of immune responses regulated locally within the liver. Both, the unique hepatic microenvironment and particular liver sinusoidal cell populations in addition to hepatocytes actively modulate immune responses locally in the liver and thereby determine the outcome of hepatic immune responses. This is of high biological and clinical relevance in hepatitis B virus (HBV) and hepatitis C virus (HCV) infections that can cause acute and persistent infections associated with chronic inflammation in humans that eventually progress to liver cirrhosis and hepatocellular carcinoma (HCC). Here, we review current knowledge about the balance between immunity and tolerance in the liver and how this may impact our understanding of the determinants of HBV and HCV clearance, persistence and virus-induced liver disease.
    Gastroenterology 01/2014; · 12.82 Impact Factor
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    ABSTRACT: Different parameters have been determined for prediction of treatment outcome in hepatitis c virus genotype 1 infected patients undergoing pegylated interferon, ribavirin combination therapy. Results on the importance of vitamin D levels are conflicting. In the present study, a comprehensive analysis of vitamin D levels before and during therapy together with single nucleotide polymorphisms involved in vitamin D metabolism in the context of other known treatment predictors has been performed. In a well characterized prospective cohort of 398 genotype 1 infected patients treated with pegylated interferon-α and ribavirin for 24-72 weeks (INDIV-2 study) 25-OH-vitamin D levels and different single nucleotide polymorphisms were analyzed together with known biochemical parameters for a correlation with virologic treatment outcome. Fluctuations of more than 5 (10) ng/ml in 25-OH-vitamin D-levels have been observed in 66 (39) % of patients during the course of antiviral therapy and neither pretreatment nor under treatment 25-OH-vitamin D-levels were associated with treatment outcome. The DHCR7-TT-polymorphism within the 7-dehydrocholesterol-reductase showed a significant association (P = 0.031) to sustained viral response in univariate analysis. Among numerous further parameters analyzed we found that age (OR = 1.028, CI = 1.002-1.056, P = 0.035), cholesterol (OR = 0.983, CI = 0.975-0.991, P<0.001), ferritin (OR = 1.002, CI = 1.000-1.004, P = 0.033), gGT (OR = 1.467, CI = 1.073-2.006, P = 0.016) and IL28B-genotype (OR = 2.442, CI = 1.271-4.695, P = 0.007) constituted the strongest predictors of treatment response. While 25-OH-vitamin D-levels levels show considerable variations during the long-lasting course of antiviral therapy they do not show any significant association to treatment outcome in genotype 1 infected patients.
    PLoS ONE 01/2014; 9(2):e87974. · 3.53 Impact Factor
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    Anita Schuch, Alexander Hoh, Robert Thimme
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    ABSTRACT: Hepatitis B virus (HBV) infection is one of the main causes of chronic liver diseases that may progress to liver cirrhosis and hepatocellular carcinoma. Host immune responses are important factors that determine whether HBV infection is cleared or persists. Natural killer (NK) cells represent the main effector population of the innate immune system and are abundant in the human liver. Recently, it has been demonstrated that NK cells not only exhibit antiviral functions but may also regulate adaptive immune responses by deletion of HBV-specific CD8(+) T cells. It is well-established that HBV-specific CD8(+) T cells contribute to virus elimination. However, the mechanisms contributing to CD8(+) T cell failure in chronic HBV infection are not well-understood. In this review, we will summarize the current knowledge about NK cells and CD8(+) T cells and illustrate their contribution to viral clearance and persistence in HBV infection. Moreover, novel immunological in vitro model systems and techniques to analyze HBV-specific CD8(+) T cells, which are barely detectable using current multimer staining methods, will be discussed.
    Frontiers in Immunology 01/2014; 5:258.
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    Euro Surveill. 01/2014; 19(21).
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    ABSTRACT: The EASL Monothematic Conference on Translational Research in Viral Hepatitis brought together a group of leading scientists and clinicians working on both, basic and clinical aspects of viral hepatitis, thereby building bridges from bench to bedside. This report recapitulates the presentations and discussions at the conference held in Lyon, France on November 29-30, 2013. In recent years, great advances have been made in the field of viral hepatitis, particularly in hepatitis C virus (HCV) infection. The identification of IL28B genetic polymorphisms as a major determinant for spontaneous and treatment-induced HCV clearance was a seminal discovery. Currently, hepatologists are at the doorstep of even greater advances, with the advent of a wealth of directly acting antivirals (DAAs) against HCV. Indeed, promising results have accumulated over the last months and few years, showing sustained virological response (SVR) rates of up to 100% with interferon-free DAA combination therapies. Thus, less than 25 years after its identification, HCV infection may soon be curable in the vast majority of patients, highlighting the great success of HCV research over the last decades. However, viral hepatitis and its clinical complications such as liver cirrhosis and hepatocellular carcinoma (HCC) remain major global challenges. New therapeutic strategies to tackle hepatitis B virus (HBV) and hepatitis D virus (HDV) infection are needed, as current therapies have undeniable limitations. Nucleoside/nucleotide analogues (NUC) can efficiently control HBV replication and reduce or even reverse liver damage. However, these drugs have to be given for indefinite periods in most patients to maintain virological and biochemical responses. Although sustained responses off treatment can be achieved by treatment with (pegylated) interferon-α, only about 10-30% of patients effectively resolve chronic hepatitis B. It was the goal of this conference to review the progress made over the last years in chronic viral hepatitis research and to identify key questions that need to be addressed in order to close the gap between basic and clinical research and to develop novel preventive and treatment approaches for this most common cause of liver cirrhosis and HCC.
    Journal of Hepatology. 01/2014;
  • Bertram Bengsch, Robert Thimme
    Hepatology International 01/2014; 8(1). · 2.64 Impact Factor
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    ABSTRACT: Cell therapy based on alloreactivity has completed clinical proof of concept against hematological malignancies. However, the efficacy of alloreactivity as a therapeutic approach to treat solid tumors is unknown. Using cell culture and animal models, we aimed to investigate the efficacy and safety of allogeneic suicide gene-modified killer cells as a cell-based therapy for hepatocellular carcinoma (HCC), for which treatment options are limited. Allogeneic killer cells from healthy donors were isolated, expanded, and phenotypically characterized. Antitumor cytotoxic activity and safety were studied using a panel of human or murine HCC cell lines engrafted in immunodeficient or immunocompetent mouse models. Human allogeneic suicide gene-modified killer cells (aSGMKCs) exhibit a high, rapid, interleukin-2-dependent, and non-major histocompatibility complex class I-restricted in vitro cytotoxicity toward human hepatoma cells, mainly mediated by natural killer (NK) and NK-like T cells. In vivo evaluation of this cell therapy product demonstrates a marked, rapid, and sustained regression of HCC. Preferential liver homing of effector cells contributed to its marked efficacy. Calcineurin inhibitors allowed preventing rejection of allogeneic lymphocytes by the host immune system without impairing their antitumor activity. Our results demonstrate proof of concept for aSGMKCs as immunotherapy for HCC and open perspectives for the clinical development of this approach.Molecular Therapy (2014); doi:10.1038/mt.2013.277.
    Molecular Therapy 12/2013; · 7.04 Impact Factor
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    ABSTRACT: Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide with a poor prognosis and limited therapeutic options. To aid the development of novel immunological interventions, we studied the breadth, frequency and tumor-infiltration of naturally occurring CD8(+) T-cell responses targeting several tumor-associated antigens (TAA). We used overlapping peptides spanning the entire AFP, GPC-3, MAGE-A1 and NY-ESO-1 proteins and major-histocompatibility-complex-class-I-tetramers specific for epitopes of MAGE-A1 and NY-ESO-1 to analyze TAA-specific CD8(+) T-cell responses in a large cohort of HCC patients. After non-specific expansion in vitro, we could detect interferon-γ (IFN-γ)-producing CD8(+) T-cells specific for all four TAA in the periphery as well as in liver and tumor tissue. These CD8(+) T-cell responses displayed clear immunodominance patterns within each TAA, but no consistent hierarchy was observed between different TAA. Importantly, the response breadth was highest in early stage HCC and associated with patient survival. After antigen-specific expansion, TAA-specific CD8(+) T-cells were detectable by tetramer staining but impaired in their ability to produce IFN-γ. Furthermore, regulatory T-cells (Treg ) were increased in HCC lesions. Depletion of Treg from cultures improved TAA-specific CD8(+) T-cell proliferation but did not restore IFN-γ-production. Conclusions: Naturally occurring TAA-specific CD8(+) T-cell responses are present in patients with HCC and therefore constitute part of the normal T-cell repertoire. Moreover, the presence of these responses correlates with patient survival. However, the observation of impaired IFN-γ-production suggests that the efficacy of such responses is functionally limited. These findings support the development of strategies that aim to enhance the total TAA-specific CD8(+) T-cell response by therapeutic boosting and/or specificity diversification. However, further research will be required to help unlock the full potential of TAA-specific CD8(+) T-cell responses. (Hepatology 2013;).
    Hepatology 09/2013; · 12.00 Impact Factor
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    ABSTRACT: HLA-B∗27 is associated with spontaneous HCV genotype 1 clearance. HLA-B∗27-restricted CD8+ T-cells target three NS5B epitopes. Two of these epitopes are dominantly targeted in the majority of HLA-B∗27+ patients. In chronic infection, viral escape occurs consistently in these two epitopes. The third epitope (NS5B2820) was dominantly targeted in an acutely infected patient. This was in contrast, however, to the lack of recognition and viral escape in the large majority of HLA-B∗27+ patients. Here, we set out to determine the host factors contributing to selective targeting of this epitope. Four-digit HLA class I typing and viral sequence analyses were performed in 78 HLA-B∗27+ patients with chronic HCV genotype 1 infection. CD8+ T-cell analyses were performed in a subset of patients. In addition, HLA/peptide affinity was compared for HLA-B∗27:02 and 05. The NS5B2820 epitope is only restricted by the HLA-B∗27 subtype HLA-B∗27:02 (that is frequent in Mediterranean populations), but not by the prototype HLA-B∗27 subtype B∗27:05. Indeed, the epitope is very dominant in HLA-B∗27:02+ patients and is associated with viral escape mutations at the anchor position for HLA-binding in 12 out of 13 HLA-B∗27:02+ chronically infected patients. The NS5B2820 epitope is immunodominant in the context of HLA-B∗27:02, but is not restricted by other HLA-B∗27 subtypes. This finding suggests an important role of HLA subtypes in the restriction of HCV-specific CD8+ responses. With minor HLA subtypes covering up to 39% of specific populations, these findings may have important implications for the selection of epitopes for global vaccines. (250/250).
    Journal of Hepatology 08/2013; · 9.86 Impact Factor
  • N Schmidt, N Büttner, R Thimme
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    ABSTRACT: Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide with a high mortality. Available therapeutical options are limited, thus the development of new, innovative therapeutic strategies is crucial. Based on the immune system's antitumoral effect, immunotherapy is a promising new treatment option. Specific antitumoral T-cell responses can be detected in patients with HCC, however, their impact on tumor control seems to be rather weak. Various different immunosuppressive mechanisms seem to contribute to the failure of tumor-specific T-cell responses. Thus, the aim of immunotherapeutic strategies is to address these mechanisms of T-cell failure and to induce new or to boost existing antitumoral immune responses.
    DMW - Deutsche Medizinische Wochenschrift 04/2013; 138(14):740-4. · 0.65 Impact Factor

Publication Stats

5k Citations
1,033.73 Total Impact Points

Institutions

  • 1999–2014
    • Universitätsklinikum Freiburg
      • • Division of Infectious Diseases
      • • Department of Internal Medicine III
      • • Department of Internal Medicine
      Freiburg an der Elbe, Lower Saxony, Germany
  • 1997–2014
    • University of Freiburg
      • • Faculty of Biology
      • • Department of Internal Medicine
      Freiburg, Baden-Württemberg, Germany
  • 2011
    • University Medical Center Schleswig-Holstein
      • Department of Pediatrics
      Kiel, Schleswig-Holstein, Germany
  • 2008–2011
    • University of Oxford
      • Nuffield Department of Clinical Medicine
      Oxford, ENG, United Kingdom
    • The National Institute of Diabetes and Digestive and Kidney Diseases
      Maryland, United States
  • 2009
    • Fundação Oswaldo Cruz
      • Departamento de Virologia (CPqAM)
      Rio de Janeiro, Rio de Janeiro, Brazil
    • Hôpital Henri Mondor (Hôpitaux Universitaires Henri Mondor)
      Créteil, Île-de-France, France
    • Universität Heidelberg
      • Department of Molecular Virology
      Heidelberg, Baden-Wuerttemberg, Germany
  • 2007
    • Université René Descartes - Paris 5
      Lutetia Parisorum, Île-de-France, France
    • Rancho Los Amigos Rehabilitation Center
      Downey, California, United States
  • 2005
    • Università degli studi di Parma
      Parma, Emilia-Romagna, Italy
  • 2000–2004
    • The Scripps Research Institute
      • • Department of Molecular and Experimental Medicine
      • • Department of Chemistry
      La Jolla, CA, United States