Publications by authors named "Uta Behrends"

47 Publications

[S1 Guideline Post-COVID/Long-COVID].

Pneumologie 2021 Nov 2;75(11):869-900. Epub 2021 Sep 2.

Österreichische Gesellschaft für Pneumologie (ÖGP).

The German Society of Pneumology initiated the AWMFS1 guideline Post-COVID/Long-COVID. In a broad interdisciplinary approach, this S1 guideline was designed based on the current state of knowledge.The clinical recommendation describes current post-COVID/long-COVID symptoms, diagnostic approaches, and therapies.In addition to the general and consensus introduction, a subject-specific approach was taken to summarize the current state of knowledge.The guideline has an expilcit practical claim and will be continuously developed and adapted by the author team based on the current increase in knowledge.
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http://dx.doi.org/10.1055/a-1551-9734DOI Listing
November 2021

Causal attributions and perceived stigma for myalgic encephalomyelitis/chronic fatigue syndrome.

J Health Psychol 2021 Jul 9:13591053211027631. Epub 2021 Jul 9.

Technical University of Munich, Germany.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic disease with the hallmark symptom of post-exertional malaise. Evidence for physiological causes is converging, however, currently no diagnostic test or biomarker is available. People with ME/CFS experience stigmatization, including the perception that the disease is psychosomatic. In a sample of 499 participants with self-diagnosed ME/CFS, we investigated perceived stigma as a pathway through which perceived others' causal attributions relate to lower satisfaction with social roles and activities and functional status. Higher perceived attributions by others to controllable and unstable causes predicted lower health-related and social outcomes via higher perceived stigma.
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http://dx.doi.org/10.1177/13591053211027631DOI Listing
July 2021

Medical Care Situation of People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Germany.

Medicina (Kaunas) 2021 Jun 23;57(7). Epub 2021 Jun 23.

German Association for ME/CFS, 20146 Hamburg, Germany.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe illness with the hallmark symptom of Post-Exertional Malaise (PEM). Currently, no biomarkers or established diagnostic tests for ME/CFS exist. In Germany, it is estimated that over 300,000 people are affected by ME/CFS. Research from the United States and the UK shows that patients with ME/CFS are medically underserved, as they face barriers to medical care access and are dissatisfied with medical care. The first aim of the current research was to investigate whether patients with ME/CFS are medically underserved in Germany in terms of access to and satisfaction with medical care. Second, we aimed at providing a German-language version of the DePaul Symptom Questionnaire Short Form (DSQ-SF) as a tool for ME/CFS diagnostics and research in German-speaking countries. The current research conducted an online questionnaire study in Germany investigating the medical care situation of patients with ME/CFS. The questionnaire was completed by 499 participants who fulfilled the Canadian Consensus Criteria and reported PEM of 14 h or longer. Participants frequently reported geographic and financial reasons for not using the available medical services. Furthermore, they reported low satisfaction with medical care by the physician they most frequently visited due to ME/CFS. The German version of the DSQ-SF showed good reliability, a one-factorial structure and construct validity, demonstrated by correlations with the SF-36 as a measure of functional status. Findings provide evidence that patients with ME/CFS in Germany are medically underserved. The German-language translation of the DSQ-SF provides a brief, reliable and valid instrument to assess ME/CFS symptoms to be used for research and clinical practice in German-speaking countries. Pathways to improve the medical care of patients with ME/CFS are discussed.
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http://dx.doi.org/10.3390/medicina57070646DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306083PMC
June 2021

European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (EUROMENE): Expert Consensus on the Diagnosis, Service Provision, and Care of People with ME/CFS in Europe.

Medicina (Kaunas) 2021 May 19;57(5). Epub 2021 May 19.

Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.

Designed by a group of ME/CFS researchers and health professionals, the European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (EUROMENE) has received funding from the European Cooperation in Science and Technology (COST)-COST action 15111-from 2016 to 2020. The main goal of the Cost Action was to assess the existing knowledge and experience on health care delivery for people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in European countries, and to enhance coordinated research and health care provision in this field. We report our findings and make recommendations for clinical diagnosis, health services and care for people with ME/CFS in Europe, as prepared by the group of clinicians and researchers from 22 countries and 55 European health professionals and researchers, who have been informed by people with ME/CFS.
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http://dx.doi.org/10.3390/medicina57050510DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161074PMC
May 2021

Needs for an Integration of Specific Data Sources and Items - First Insights of a National Survey Within the German Center for Infection Research.

Stud Health Technol Inform 2021 May;278:237-244

German Center for Infection Research (DZIF), Braunschweig, Germany.

State-subsidized programs develop medical data integration centers in Germany. To get infection disease (ID) researchers involved in the process of data sharing, common interests and minimum data requirements were prioritized. In 06/2019 we have initiated the German Infectious Disease Data Exchange (iDEx) project. We have developed and performed an online survey to determine prioritization of requests for data integration and exchange in ID research. The survey was designed with three sub-surveys, including a ranking of 15 data categories and 184 specific data items and a query of available 51 data collecting systems. A total of 84 researchers from 17 fields of ID research participated in the survey (predominant research fields: gastrointestinal infections n=11, healthcare-associated and antibiotic-resistant infections n=10, hepatitis n=10). 48% (40/84) of participants had experience as medical doctor. The three top ranked data categories were microbiology and parasitology, experimental data, and medication (53%, 52%, and 47% of maximal points, respectively). The most relevant data items for these categories were bloodstream infections, availability of biomaterial, and medication (88%, 87%, and 94% of maximal points, respectively). The ranking of requests of data integration and exchange is diverse and depends on the chosen measure. However, there is need to promote discipline-related digitalization and data exchange.
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http://dx.doi.org/10.3233/SHTI210075DOI Listing
May 2021

Swarm Learning for decentralized and confidential clinical machine learning.

Nature 2021 06 26;594(7862):265-270. Epub 2021 May 26.

Systems Medicine, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Bonn, Germany.

Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine. Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes. However, there is an increasing divide between what is technically possible and what is allowed, because of privacy legislation. Here, to facilitate the integration of any medical data from any data owner worldwide without violating privacy laws, we introduce Swarm Learning-a decentralized machine-learning approach that unites edge computing, blockchain-based peer-to-peer networking and coordination while maintaining confidentiality without the need for a central coordinator, thereby going beyond federated learning. To illustrate the feasibility of using Swarm Learning to develop disease classifiers using distributed data, we chose four use cases of heterogeneous diseases (COVID-19, tuberculosis, leukaemia and lung pathologies). With more than 16,400 blood transcriptomes derived from 127 clinical studies with non-uniform distributions of cases and controls and substantial study biases, as well as more than 95,000 chest X-ray images, we show that Swarm Learning classifiers outperform those developed at individual sites. In addition, Swarm Learning completely fulfils local confidentiality regulations by design. We believe that this approach will notably accelerate the introduction of precision medicine.
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http://dx.doi.org/10.1038/s41586-021-03583-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8189907PMC
June 2021

HCoV- and SARS-CoV-2 Cross-Reactive T Cells in CVID Patients.

Front Immunol 2020 23;11:607918. Epub 2020 Dec 23.

Institute of Medical Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.

The inability of patients with CVID to mount specific antibody responses to pathogens has raised concerns on the risk and severity of SARS-CoV-2 infection, but there might be a role for protective T cells in these patients. SARS-CoV-2 reactive T cells have been reported for SARS-CoV-2 unexposed healthy individuals. Until now, there is no data on T cell immunity to SARS-CoV-2 infection in CVID. This study aimed to evaluate reactive T cells to human endemic corona viruses (HCoV) and to study pre-existing SARS-CoV-2 reactive T cells in unexposed CVID patients. We evaluated SARS-CoV-2- and HCoV-229E and -OC43 reactive T cells in response to seven peptide pools, including spike and nucleocapsid (NCAP) proteins, in 11 unexposed CVID, 12 unexposed and 11 post COVID-19 healthy controls (HC). We further characterized reactive T cells by IFNγ, TNFα and IL-2 profiles. SARS-CoV-2 spike-reactive CD4+ T cells were detected in 7 of 11 unexposed CVID patients, albeit with fewer multifunctional (IFNγ/TNFα/IL-2) cells than unexposed HC. CVID patients had no SARS-CoV-2 NCAP reactive CD4+ T cells and less reactive CD8+ cells compared to unexposed HC. We observed a correlation between T cell reactivity against spike of SARS-CoV-2 and HCoVs in unexposed, but not post COVID-19 HC, suggesting cross-reactivity. T cell responses in post COVID-19 HC could be distinguished from unexposed HC by higher frequencies of triple-positive NCAP reactive CD4+ T cells. Taken together, SARS-CoV-2 reactive T cells are detectable in unexposed CVID patients albeit with lower recognition frequencies and polyfunctional potential. Frequencies of triple-functional reactive CD4+ cells might provide a marker to distinguish HCoV cross-reactive from SARS-CoV-2 specific T cell responses. Our data provides evidence, that anti-viral T cell immunity is not relevantly impaired in most CVID patients.
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http://dx.doi.org/10.3389/fimmu.2020.607918DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7785785PMC
January 2021

First results of the "Lean European Open Survey on SARS-CoV-2-Infected Patients (LEOSS)".

Infection 2021 Feb 1;49(1):63-73. Epub 2020 Oct 1.

Department I for Internal Medicine, University Hospital of Cologne, University of Cologne, Cologne, Germany.

Purpose: Knowledge regarding patients' clinical condition at severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection is sparse. Data in the international, multicenter Lean European Open Survey on SARS-CoV-2-Infected Patients (LEOSS) cohort study may enhance the understanding of COVID-19.

Methods: Sociodemographic and clinical characteristics of SARS-CoV-2-infected patients, enrolled in the LEOSS cohort study between March 16, 2020, and May 14, 2020, were analyzed. Associations between baseline characteristics and clinical stages at diagnosis (uncomplicated vs. complicated) were assessed using logistic regression models.

Results: We included 2155 patients, 59.7% (1,287/2,155) were male; the most common age category was 66-85 years (39.6%; 500/2,155). The primary COVID-19 diagnosis was made in 35.0% (755/2,155) during complicated clinical stages. A significant univariate association between age; sex; body mass index; smoking; diabetes; cardiovascular, pulmonary, neurological, and kidney diseases; ACE inhibitor therapy; statin intake and an increased risk for complicated clinical stages of COVID-19 at diagnosis was found. Multivariable analysis revealed that advanced age [46-65 years: adjusted odds ratio (aOR): 1.73, 95% CI 1.25-2.42, p = 0.001; 66-85 years: aOR 1.93, 95% CI 1.36-2.74, p < 0.001; > 85 years: aOR 2.38, 95% CI 1.49-3.81, p < 0.001 vs. individuals aged 26-45 years], male sex (aOR 1.23, 95% CI 1.01-1.50, p = 0.040), cardiovascular disease (aOR 1.37, 95% CI 1.09-1.72, p = 0.007), and diabetes (aOR 1.33, 95% CI 1.04-1.69, p = 0.023) were associated with complicated stages of COVID-19 at diagnosis.

Conclusion: The LEOSS cohort identified age, cardiovascular disease, diabetes and male sex as risk factors for complicated disease stages at SARS-CoV-2 diagnosis, thus confirming previous data. Further data regarding outcomes of the natural course of COVID-19 and the influence of treatment are required.
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http://dx.doi.org/10.1007/s15010-020-01499-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7527665PMC
February 2021

MYSM1 maintains ribosomal protein gene expression in hematopoietic stem cells to prevent hematopoietic dysfunction.

JCI Insight 2020 07 9;5(13). Epub 2020 Jul 9.

Department of Physiology.

Ribosomopathies are congenital disorders caused by mutations in the genes encoding ribosomal and other functionally related proteins. They are characterized by anemia, other hematopoietic and developmental abnormalities, and p53 activation. Ribosome assembly requires coordinated expression of many ribosomal protein (RP) genes; however, the regulation of RP gene expression, especially in hematopoietic stem cells (HSCs), remains poorly understood. MYSM1 is a transcriptional regulator essential for HSC function and hematopoiesis. We established that HSC dysfunction in Mysm1 deficiency is driven by p53; however, the mechanisms of p53 activation remained unclear. Here, we describe the transcriptome of Mysm1-deficient mouse HSCs and identify MYSM1 genome-wide DNA binding sites. We establish a direct role for MYSM1 in RP gene expression and show a reduction in protein synthesis in Mysm1-/- HSCs. Loss of p53 in mice fully rescues Mysm1-/- anemia phenotype but not RP gene expression, indicating that RP gene dysregulation is a direct outcome of Mysm1 deficiency and an upstream mediator of Mysm1-/- phenotypes through p53 activation. We characterize a patient with a homozygous nonsense MYSM1 gene variant, and we demonstrate reduced protein synthesis and increased p53 levels in patient hematopoietic cells. Our work provides insights into the specialized mechanisms regulating RP gene expression in HSCs and establishes a common etiology of MYSM1 deficiency and ribosomopathy syndromes.
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http://dx.doi.org/10.1172/jci.insight.125690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7406308PMC
July 2020

Evaluation of T-activated proteins as recall antigens to monitor Epstein-Barr virus and human cytomegalovirus-specific T cells in a clinical trial setting.

J Transl Med 2020 06 17;18(1):242. Epub 2020 Jun 17.

Institute of Virology, Helmholtz Zentrum München/Technical University of Munich, School of Medicine, Schneckenburgerstr. 8, 81675, Munich, Germany.

Background: Pools of overlapping synthetic peptides are routinely used for ex vivo monitoring of antigen-specific T-cell responses. However, it is rather unlikely that these peptides match those resulting from naturally processed antigens. T-activated proteins have been described as immunogenic and more natural stimulants, since they have to pass through antigen processing and comprise activation of all clinically relevant effector cell populations.

Methods: We performed comparative analysis of numbers and cytokine expression pattern of CD4 and CD8 T cells after stimulation with recombinant, urea-formulated T-activated EBV-BZLF1, -EBNA3A, and HCMV-IE1, and -pp65 proteins or corresponding overlapping peptide pools. Freshly isolated and cryopreserved PBMC of 30 EBV- and 19 HCMV-seropositive and seven EBV- and HCMV-seronegative subjects were stimulated ex vivo and analysed for IFN-γ, TNF and IL-2 production by flow cytometry-based intracellular cytokine staining.

Results: T-activated proteins showed a high specificity of 100% (EBV-BZLF1, HCMV-IE1, and -pp65) and 86% (EBV-EBNA3A), and a high T-cell stimulatory capacity of 73-95% and 67-95% using freshly isolated and cryopreserved PBMC, respectively. The overall CD4 T-cell response rates in both cohorts were comparable after stimulation with either T-activated protein or peptide pools with the exception of lower numbers of CD8 T cells detected after stimulation with T-activated EBV-EBNA3A- (p = 0.038) and HCMV-pp65- (p = 0.0006). Overall, the number of detectable antigen-specific T cells varied strongly between individuals. Cytokine expression patterns in response to T-activated protein and peptide pool-based stimulation were similar for CD4, but significantly different for CD8 T-cell responses.

Conclusion: EBV and HCMV-derived T-activated proteins represent innovative, highly specific recall antigens suitable for use in immunological endpoint assays to evaluate success or failure in immunotherapy clinical trials (e.g. to assess the risk of EBV and/or HCMV reactivation after allogenic hematopoietic stem cell transplantation). T-activated proteins could be of particular importance, if an impaired antigen processing (e.g. in a post-transplant setting) must be taken into account.
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http://dx.doi.org/10.1186/s12967-020-02385-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7298696PMC
June 2020

The Epstein-Barr Virus Major Tegument Protein BNRF1 Is a Common Target of Cytotoxic CD4 T Cells.

J Virol 2020 07 16;94(15). Epub 2020 Jul 16.

Children's Hospital, School of Medicine, Technical University of Munich, Munich, Germany

Cellular immunotherapy is a proven approach against Epstein-Barr virus (EBV)-driven lymphoproliferation in recipients of hematopoietic stem cells. Extending the applicability and improving the response rates of such therapy demands improving the knowledge base. We studied 23 healthy donors for specific CD4 T cell responses against the viral tegument protein BNRF1 and found such T cells in all seropositive donors, establishing BNRF1 as an important immune target in EBV. We identified 18 novel immune epitopes from BNRF1, all of them generated by natural processing of the full-length protein from virus-transformed lymphoblastoid cell lines (LCL). BNRF1-specific CD4 T cells were measured directly by a cytokine-based method, thus providing a tool to study the interaction between immunity and infection in health and disease. T cells of the cytotoxic Th1 type inhibited the proliferation of autologous LCL as well as virus-driven transformation. We infer that they are important in limiting reactivations to subclinical levels during health and reducing virus propagation during disease. The information obtained from this work will feed into data sets that are indispensable in the design of patient-tailored immunotherapeutic approaches, thereby enabling the stride toward broader application of T cell therapy and improving clinical response rates. Epstein-Barr virus is carried by most humans and can cause life-threatening diseases. Virus-specific T cells have been used in different clinical settings with variable success rates. One way to improve immunotherapy is to better suit T cell generation protocols to viral targets available in different diseases. BNRF1 is present in viral particles and therefore likely available as a target for T cells in diseases with virus amplification. Here, we studied healthy Epstein-Barr virus (EBV) carriers for BNRF1 immunogenicity and report our results indicating BNRF1 to be a dominant target of the EBV-specific CD4 T cell response. BNRF1-specific CD4 T cells were found to be cytotoxic and capable of limiting EBV-driven B cell transformation The findings of this work contribute to forwarding our understanding of host-virus interactions during health and disease and are expected to find direct application in the generation of specific T cells for immunotherapy.
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http://dx.doi.org/10.1128/JVI.00284-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7375367PMC
July 2020

Identification and Cloning of a New Western Epstein-Barr Virus Strain That Efficiently Replicates in Primary B Cells.

J Virol 2020 05 4;94(10). Epub 2020 May 4.

German Cancer Research Centre (DKFZ), Unit F100, Heidelberg, Germany

The Epstein-Barr virus (EBV) causes human cancers, and epidemiological studies have shown that lytic replication is a risk factor for some of these tumors. This fits with the observation that EBV M81, which was isolated from a Chinese patient with nasopharyngeal carcinoma, induces potent virus production and increases the risk of genetic instability in infected B cells. To find out whether this property extends to viruses found in other parts of the world, we investigated 22 viruses isolated from Western patients. While one-third of the viruses hardly replicated, the remaining viruses showed variable levels of replication, with three isolates replicating at levels close to that of M81 in B cells. We cloned one strongly replicating virus into a bacterial artificial chromosome (BAC); the resulting recombinant virus (MSHJ) retained the properties of its nonrecombinant counterpart and showed similarities to M81, undergoing lytic replication and after 3 weeks of latency. In contrast, B cells infected with the nonreplicating Western B95-8 virus showed early but abortive replication accompanied by cytoplasmic BZLF1 expression. Sequencing confirmed that rMSHJ is a Western virus, being genetically much closer to B95-8 than to M81. Spontaneous replication in rM81- and rMSHJ-infected B cells was dependent on phosphorylated Btk and was inhibited by exposure to ibrutinib, opening the way to clinical intervention in patients with abnormal EBV replication. As rMSHJ contains the complete EBV genome and induces lytic replication in infected B cells, it is ideal to perform genetic analyses of all viral functions in Western strains and their associated diseases. The Epstein-Barr virus (EBV) infects the majority of the world population but causes different diseases in different countries. Evidence that lytic replication, the process that leads to new virus progeny, is linked to cancer development is accumulating. Indeed, viruses such as M81 that were isolated from Far Eastern nasopharyngeal carcinomas replicate strongly in B cells. We show here that some viruses isolated from Western patients, including the MSHJ strain, share this property. Moreover, replication of both M81 and of MSHJ was sensitive to ibrutinib, a commonly used drug, thereby opening an opportunity for therapeutic intervention. Sequencing of MSHJ showed that this virus is quite distant from M81 and is much closer to nonreplicating Western viruses. We conclude that Western EBV strains are heterogeneous, with some viruses being able to replicate more strongly and therefore being potentially more pathogenic than others, and that the virus sequence information alone cannot predict this property.
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http://dx.doi.org/10.1128/JVI.01918-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7199418PMC
May 2020

Differential upregulation of host cell protein kinases by the replication of α-, β- and γ-herpesviruses provides a signature of virus-specific signalling.

J Gen Virol 2020 03;101(3):284-289

Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Erlangen, Germany.

Infections with human herpesviruses share several molecular characteristics, but the diversified medical outcomes are distinct to viral subfamilies and species. Notably, both clinical and molecular correlates of infection are a challenging field and distinct patterns of virus-host interaction have rarely been defined; this study therefore focuses on the search for virus-specific molecular indicators. As previous studies have demonstrated the impact of herpesvirus infections on changes in host signalling pathways, we illustrate virus-modulated expression levels of individual cellular protein kinases. Current data reveal (i) α-, β- and γ-herpesvirus-specific patterns of kinase modulation as well as (ii) differential levels of up-/downregulated kinase expression and phosphorylation, which collectively suggest (iii) defined signalling patterns specific for the various viruses (VSS) that may prove useful for defining molecular indicators. Combined, the study confirms the correlation between herpesviral replication and modulation of signalling kinases, possibly exploitable for the characterization of viral infections.
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http://dx.doi.org/10.1099/jgv.0.001370DOI Listing
March 2020

Improvement of Guideline Adherence After the Implementation of an Antibiotic Stewardship Program in a Secondary Care Pediatric Hospital.

Front Pediatr 2019 13;7:478. Epub 2019 Nov 13.

Klinik für Kinder- und Jugendmedizin, München Klinik Schwabing und Harlaching; and Department of Pediatrics, Technical University of Munich School of Medicine, Munich, Germany.

The accelerating threat of multidrug-resistant bacteria (MRB) forces health care providers to use antibiotics more rationally. Antibiotic stewardship programs (ASP) are a proven and safe way to achieve that goal. They have been comprehensively studied in adults but data from secondary care pediatric hospitals are lacking. In our study an ASP with standard operating procedures (SOPs), audits, a weekly ward round with experts in pediatric infectious diseases and an antibiotic pocket-card for selected infectious diseases was established in July 2017 in a Munich municipal secondary care children's hospital. All antibiotic prescriptions on general pediatric wards were reviewed each in the first quarter of 2017 and 2018. The primary outcome was adherence to treatment guidelines. Secondary outcomes were substance consumption, duration of therapy and death. After the ASP was implemented guideline adherence increased significantly from 33 to 63%. The consumption of cephalosporins decreased significantly (-60%), whereas aminopenicillin use increased accordingly (+120%). Neither in the pre- nor in the post-intervention group deaths occurred. Data on ASP in pediatric secondary care hospitals are scarce. Most previous studies have been performed at tertiary care/university children's hospitals. We demonstrate a significant improvement in guideline adherence regarding antibiotic treatments after the implementation of an ASP. Cephalosporin consumption decreased which might be relevant for the selection of MRB (e.g., vancomycin-resistant enterococci). Results are limited by the single-center design and the short observation period. The study encourages the implementation of ASPs in secondary care children's hospitals.
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http://dx.doi.org/10.3389/fped.2019.00478DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6865353PMC
November 2019

Spontaneous lymphoblastoid cell lines from patients with Epstein-Barr virus infection show highly variable proliferation characteristics that correlate with the expression levels of viral microRNAs.

PLoS One 2019 30;14(9):e0222847. Epub 2019 Sep 30.

German Cancer Research Centre (DKFZ) Unit F100, Heidelberg, Germany.

The Epstein-Barr virus (EBV) induces B-cell proliferation with high efficiency through expression of latent proteins and microRNAs. This process takes place in vivo soon after infection, presumably to expand the virus reservoir, but can also induce pathologies, e.g. an infectious mononucleosis (IM) syndrome after primary infection or a B-cell lymphoproliferation in immunosuppressed individuals. In this paper, we investigated the growth characteristics of EBV-infected B-cells isolated from transplant recipients or patients with IM. We found that these cells grew and withstood apoptosis at highly variable rates, suggesting that the expansion rate of the infected B-cells widely varies between individuals, thereby influencing the size of the B-cell reservoir and the ability to form tumors in infected individuals. All viruses investigated were type 1 and genetically close to western strains. EBV-infected B-cells expressed the transforming EBV latent genes and microRNAs (miRNAs) at variable levels. We found that the B-cell growth rates positively correlated with the BHRF1 miRNA levels. Comparative studies showed that infected B-cells derived from transplant recipients with iEBVL on average expressed higher levels of EBV miR-BHRF1 miRNAs and grew more rapidly than B-cells from IM patients, suggesting infection by more transforming viruses. Altogether, these findings suggest that EBV infection has a highly variable impact on the B-cell compartment that probably reflects the genetic diversity of both the virus and the host. It also demonstrates the unexpected finding that B-cells from different individuals can grow at different speed under the influence of the same virus infection.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222847PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6768455PMC
March 2020

The German National Registry of Primary Immunodeficiencies (2012-2017).

Front Immunol 2019 19;10:1272. Epub 2019 Jul 19.

Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany.

The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs. Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel. The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1-25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0-88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE- syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%-subcutaneous; 29%-intravenous; 1%-unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy. The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment.
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http://dx.doi.org/10.3389/fimmu.2019.01272DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6659583PMC
October 2020

Proteome Analysis of Human Neutrophil Granulocytes From Patients With Monogenic Disease Using Data-independent Acquisition.

Mol Cell Proteomics 2019 04 10;18(4):760-772. Epub 2019 Jan 10.

From the ‡Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany;; ¶Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK;. Electronic address:

Neutrophil granulocytes are critical mediators of innate immunity and tissue regeneration. Rare diseases of neutrophil granulocytes may affect their differentiation and/or functions. However, there are very few validated diagnostic tests assessing the functions of neutrophil granulocytes in these diseases. Here, we set out to probe omics analysis as a novel diagnostic platform for patients with defective differentiation and function of neutrophil granulocytes. We analyzed highly purified neutrophil granulocytes from 68 healthy individuals and 16 patients with rare monogenic diseases. Cells were isolated from fresh venous blood (purity >99%) and used to create a spectral library covering almost 8000 proteins using strong cation exchange fractionation. Patient neutrophil samples were then analyzed by data-independent acquisition proteomics, quantifying 4154 proteins in each sample. Neutrophils with mutations in the neutrophil elastase gene showed large proteome changes that suggest these mutations may affect maturation of neutrophil granulocytes and initiate misfolded protein response and cellular stress mechanisms. In contrast, only few proteins changed in patients with leukocyte adhesion deficiency (LAD) and chronic granulomatous disease (CGD). Strikingly, neutrophil transcriptome analysis showed no correlation with its proteome. In case of two patients with undetermined genetic causes, proteome analysis guided the targeted genetic diagnostics and uncovered the underlying genomic mutations. Data-independent acquisition proteomics may help to define novel pathomechanisms in neutrophil diseases and provide a clinically useful diagnostic dimension.
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http://dx.doi.org/10.1074/mcp.RA118.001141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442368PMC
April 2019

Epstein-Barr Virus Induces Expression of the LPAM-1 Integrin in B Cells and .

J Virol 2019 03 19;93(5). Epub 2019 Feb 19.

German Cancer Research Centre (DKFZ), Unit F100, Heidelberg, Germany

Epstein-Barr virus (EBV) infects the oropharynx but, surprisingly, frequently induces B cell proliferation in the gut of immunosuppressed individuals. We found that EBV infection induces the expression of the LPAM-1 integrin on tonsillar B cells and increases it on peripheral blood cells. Similarly, LPAM-1 was induced in the tonsils of patients undergoing primary infectious mononucleosis. EBV-induced LPAM-1 bound to the MAdCAM-1 addressin, which allows B cell homing to the gastrointestinal mucosa-associated lymphoid tissue (GALT). Thus, we hypothesized that EBV-induced LPAM-1 could induce relocation of infected B cells from the tonsil to the GALT. hybridization with an EBER-specific probe revealed the frequent presence of EBV-infected cells in the pericolic lymph nodes of healthy individuals. Relocation of infected B cells into the GALT would expand the EBV reservoir, possibly protecting it from T cells primed in the oropharynx, and explain why EBV induces lymphoid tumors in the gut. EBV causes tumors in multiple organs, particularly in the oro- and nasopharyngeal area but also in the digestive system. This virus enters the body in the oropharynx and establishes a chronic infection in this area. The observation that the virus causes tumors in the digestive system implies that the infected cells can move to this organ. We found that EBV infection induces the expression of integrin beta 7 (ITGB7), an integrin that associates with integrin alpha 4 to form the LPAM-1 dimer. LPAM-1 is key for homing of B cells to the gastrointestinal tract, suggesting that induction of this molecule is the mechanism through which EBV-infected cells enter this organ. In favor of this hypothesis, we could also detect EBV-infected cells in the lymph nodes adjacent to the colon and in the appendix.
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http://dx.doi.org/10.1128/JVI.01618-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384065PMC
March 2019

[Recommendations for Diagnostics and Therapy of Children with Cancer Presenting with Fever and Neutropenia - Comparison of Two Current Guidelines].

Klin Padiatr 2018 Apr 27;230(3):115-121. Epub 2018 Mar 27.

Pädiatrische Hämatologie und Onkologie, Universitätskinderklinik, Homburg.

Immunocompromised children and adolescents receiving treatment for cancer have a considerably increased risk for infection. Neutropenia is the most important single risk factor for infectious complications, and fever in neutropenia is considered as an emergency. Whereas guidelines for the management of fever in neutropenic adults have been established for decades, specific pediatric guidelines have not been developed until recently. As children differ in many aspects from adults such as in the underlying malignancy or in the availability and dosing of antimicrobial compounds, guidelines for pediatric patients are important. This article reviews similarities and differences between the recently published German interdisciplinary guideline of the German Societies of Pediatric Infectious Diseases and Pediatric Oncology and Hematology and a guideline developed by a panel of international experts for the management of fever in neutropenia in children and adolescents.
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http://dx.doi.org/10.1055/s-0044-101953DOI Listing
April 2018

Epstein-Barr virus strain heterogeneity impairs human T-cell immunity.

Cancer Immunol Immunother 2018 Apr 27;67(4):663-674. Epub 2018 Jan 27.

Children's Hospital, Technische Universität München, Munich, Germany.

The Epstein-Barr virus (EBV) establishes lifelong infections in > 90% of the human population. Although contained as asymptomatic infection by the immune system in most individuals, EBV is associated with the pathogenesis of approximately 1.5% of all cancers in humans. Some of these EBV-associated tumors have been successfully treated by the infusion of virus-specific T-cell lines. Recent sequence analyses of a large number of viral isolates suggested that distinct EBV strains have evolved in different parts of the world. Here, we assessed the impact of such sequence variations on EBV-specific T-cell immunity. With the exceptions of EBNA2 and the EBNA3 family of proteins, an overall low protein sequence disparity of about 1% was noted between Asian viral isolates, including the newly characterized M81 strain, and the prototypic EBV type 1 and type 2 strains. However, when T-cell epitopes including their flanking regions were compared, a substantial proportion was found to be polymorphic in different EBV strains. Importantly, CD4+ and CD8+ T-cell clones specific for viral epitopes from one strain often showed diminished recognition of the corresponding epitopes in other strains. In addition, T-cell recognition of a conserved epitope was affected by amino acid exchanges within the epitope flanking region. Moreover, the CD8+ T-cell response against polymorphic epitopes varied between donors and often ignored antigen variants. These results demonstrate that viral strain heterogeneity may impair antiviral T-cell immunity and suggest that immunotherapeutic approaches against EBV should preferably target broad sets of conserved epitopes including their flanking regions.
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http://dx.doi.org/10.1007/s00262-018-2118-zDOI Listing
April 2018

Serological profiling of the EBV immune response in Chronic Fatigue Syndrome using a peptide microarray.

PLoS One 2017 12;12(6):e0179124. Epub 2017 Jun 12.

Institute of Medical Immunology, Charité University Medicine Berlin, Campus Virchow, Berlin, Germany.

Background: Epstein-Barr-Virus (EBV) plays an important role as trigger or cofactor for various autoimmune diseases. In a subset of patients with Chronic Fatigue Syndrome (CFS) disease starts with infectious mononucleosis as late primary EBV-infection, whereby altered levels of EBV-specific antibodies can be observed in another subset of patients.

Methods: We performed a comprehensive mapping of the IgG response against EBV comparing 50 healthy controls with 92 CFS patients using a microarray platform. Patients with multiple sclerosis (MS), systemic lupus erythematosus (SLE) and cancer-related fatigue served as controls. 3054 overlapping peptides were synthesised as 15-mers from 14 different EBV proteins. Array data was validated by ELISA for selected peptides. Prevalence of EBV serotypes was determined by qPCR from throat washing samples.

Results: EBV type 1 infections were found in patients and controls. EBV seroarray profiles between healthy controls and CFS were less divergent than that observed for MS or SLE. We found significantly enhanced IgG responses to several EBNA-6 peptides containing a repeat sequence in CFS patients compared to controls. EBNA-6 peptide IgG responses correlated well with EBNA-6 protein responses. The EBNA-6 repeat region showed sequence homologies to various human proteins.

Conclusion: Patients with CFS had a quite similar EBV IgG antibody response pattern as healthy controls. Enhanced IgG reactivity against an EBNA-6 repeat sequence and against EBNA-6 protein is found in CFS patients. Homologous sequences of various human proteins with this EBNA-6 repeat sequence might be potential targets for antigenic mimicry.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179124PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467847PMC
September 2017

The Epstein-Barr virus DNA load in the peripheral blood of transplant recipients does not accurately reflect the burden of infected cells.

Transpl Int 2017 Jan 5;30(1):57-67. Epub 2016 Nov 5.

German Cancer Research Centre (DKFZ) Unit F100, Heidelberg, Germany.

Transplant recipients frequently exhibit an increased Epstein-Barr virus (EBV) load in the peripheral blood. Here, we quantitated the EBV-infected cells in the peripheral blood of these patients and defined the mode of viral infection, latent or lytic. These data indicated that there is no strong correlation between the number of infected cells and the EBV load (EBVL). This can be explained by a highly variable number of EBV copies per infected cell and by lytic replication in some cells. The plasma of these patients did not contain any free infectious viruses, but contained nevertheless EBV DNA, sometimes in large amounts, that probably originates from cell debris and contributed to the total EBVL. Some of the investigated samples carried a highly variable number of infected cells in active latency, characterized by an expression of the Epstein-Barr nuclear antigens (EBNA2) protein. However, a third of the samples expressed neither EBNA2 nor lytic proteins. Patients with an increased EBVL represent a heterogeneous group of patients whose infection cannot be characterized by this method alone. Precise characterization of the origin of an increased EBVL, in particular, in terms of the number of EBV-infected cells, requires additional investigations including the number of EBV-encoded small RNA-positive cells.
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http://dx.doi.org/10.1111/tri.12871DOI Listing
January 2017

Validation of an IFNγ/IL2 FluoroSpot assay for clinical trial monitoring.

J Transl Med 2016 06 14;14(1):175. Epub 2016 Jun 14.

Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Schneckenburgerstr. 8, 81675, Munich, Germany.

Background: The FluoroSpot assay, an advancement of the ELISpot assay, enables simultaneous measurement of different analytes secreted at a single-cell level. This allows parallel detection of several cytokines secreted by immune cells upon antigen recognition. Easier standardization, higher sensitivity and reduced labour intensity render FluoroSpot assays an interesting alternative to flow-cytometry based assays for analysis of clinical samples. While the use of immunoassays to study immunological primary and secondary endpoints becomes increasingly attractive, assays used require pre-trial validation. Here we describe the assay validation (precision, specificity and linearity) of a FluoroSpot immunological endpoint assay detecting Interferon γ (IFNγ) and Interleukin 2 (IL2) for use in clinical trial immune monitoring.

Methods: We validated an IFNγ/IL2 FluoroSpot assay to determine Epstein-Barr virus (EBV)-specific cellular immune responses (IFNγ, IL2 and double positive IFNγ + IL2 responses), using overlapping peptide pools corresponding to EBV-proteins BZLF1 and EBNA3A. Assay validation was performed using cryopreserved PBMC of 16 EBV-seropositive and 6 EBV-seronegative donors. Precision was assessed by (i) testing 16 donors using three replicates per assay (intra-assay precision/repeatability) (ii) using two plates in parallel (intermediate precision/plate-to-plate variability) and (iii) by performing the assays on three different days (inter-assay precision/reproducibility). In addition, we determined specificity, linearity and quantification limits of the assay. Further we tested precision across the two assay systems, IFNγ/IL2 FluoroSpot and the corresponding enzymatic single cytokine ELISpot.

Results: The validation revealed: (1) a high intra-assay precision (coefficient of variation (CV) 9.96, 8.85 and 13.05 %), intermediate precision (CV 6.48, 10.20 and 12.97 %) and reproducibility (CV 20.81 %, 12,75 % and 12.07 %) depending on the analyte and antigen used; (2) a specificity of 100 %; (3) a linearity with R (2) values from 0.93 to 0.99 depending on the analyte. The testing of the precision across the two assay systems, adduced a concordance correlation coefficient p c  = 0.99 for IFNγ responses and p c  = 0.93 for IL2 responses, indicating a large agreement between both assay methods.

Conclusions: The validated primary endpoint assay, an EBV peptide pool specific IFNγ/IL2 FluoroSpot assay was found to be suitable for the detection of EBV-specific immune responses subject to the requirement of standardized assay procedure and data analysis.
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http://dx.doi.org/10.1186/s12967-016-0932-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4906590PMC
June 2016

Immune Thrombocytopenia in Two Unrelated Fanconi Anemia Patients - A Mere Coincidence?

Front Pediatr 2015 8;3:50. Epub 2015 Jun 8.

Division of Pediatric Hematology/Oncology, Department of Pediatrics and Adolescent Medicine, Medical University Graz , Graz , Austria.

Thrombocytopenia and pancytopenia, occurring in patients with Fanconi anemia (FA), are interpreted either as progression to bone marrow failure or as developing myelodysplasia. On the other hand, immune thrombocytopenia (ITP) represents an acquired and often self-limiting benign hematologic disorder, associated with peripheral, immune-mediated, platelet destruction requiring different management modalities than those used in congenital bone marrow failure syndromes, including FA. Here, we describe the clinical course of two independent FA patients with atypical - namely immune - thrombocytopenia. While in one patient belonging to complementation group FA-A, the ITP started at 17 months of age and showed a chronically persisting course with severe purpura, responding well to intravenous immunoglobulins (IVIG) and later also danazol, a synthetic androgen, the other patient (of complementation group FA-D2) had a self-limiting course that resolved after one administration of IVIG. No cytogenetic aberrations or bone marrow abnormalities other than FA-typical mild dysplasia were detected. Our data show that acute and chronic ITP may occur in FA patients and impose individual diagnostic and therapeutic challenges in this rare congenital bone marrow failure/tumor predisposition syndrome. The management and a potential context of immune pathogenesis with the underlying marrow disorder are discussed.
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http://dx.doi.org/10.3389/fped.2015.00050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459098PMC
June 2015

Polyubiquitination of lysine-48 is an essential but indirect signal for MHC class I antigen processing.

Eur J Immunol 2015 Mar 15;45(3):716-27. Epub 2015 Jan 15.

Clinical Cooperation Group Pediatric Tumor Immunology, Children's Hospital, Technische Universität München, Munich, Germany; Helmholtz ZentrumMünchen, Munich, Germany; German Centre for Infection Research (DZIF), Germany.

Peptides presented on major histocompatibility complex (MHC) class I molecules are generated via cytosolic proteolysis. However, the nature of the endogenous peptide precursors and the intracellular processing steps preceding protein degradation remain poorly defined. Here, we assessed whether ubiquitination is an essential signal for proteasomal cleavage of antigen substrates in human cells. Conversion into antigenic peptides occurred in the absence of any detectable N-terminal ubiquitination of the model antigens, and did not require the presence of any of the four types, nor a minimum number of ubiquitinatable amino acids within the antigen substrate. However, the knockdown of ubiquitin, expression of a lysine 48 (K48) ubiquitin mutant, or inhibition of proteasome-associated deubiquitinases significantly impaired antigen presentation. The results presented here are consistent with a model in which the binding of the antigen substrate by an adaptor protein leads to its K48-polyubiquitination and the subsequent delivery of the antigen cargo for degradation by the 26S proteasome. Altogether, these findings show an important but indirect role of K48-polyubiquitination in preproteasomal antigen sampling.
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http://dx.doi.org/10.1002/eji.201444830DOI Listing
March 2015

Clinical and genetic features of rhabdoid tumors of the heart registered with the European Rhabdoid Registry (EU-RHAB).

Cancer Genet 2014 Sep 21;207(9):379-83. Epub 2014 Apr 21.

Children's Hospital Augsburg, Swabian Children's Cancer Center, Augsburg, Germany; Department of Pediatric Hematology and Oncology, University Children's Hospital Münster, Germany. Electronic address:

Rhabdoid tumors are rare but highly aggressive malignancies of infancy and early childhood with a generally unfavorable prognosis. Despite a wide variety of anatomic locations rhabdoid tumors share mutational inactivation of the SWI/SNF (SWItch/Sucrose NonFermentable) core component gene SMARCB1 (also known as INI1, hSNF5 or BAF47) in chromosome 22. As this inactivation usually results in loss of SMARCB1 expression, detectable by an antibody against the SMARCB1 protein, the accurate diagnosis of a rhabdoid tumor may be more distinctly and frequently made. Several reports on rhabdoid tumors presenting in various anatomic sites outside the kidneys and CNS are on record. We report two cases of rhabdoid tumors originating in the heart (cardiac tissue), which were entered into the European Rhabdoid Registry (EU-RHAB). The first case presented with intracardial and -cranial lesions as well as malignant ascites, while the second patient demonstrated an isolated cardiac tumor. This induced a different therapeutic approach and subsequently different clinical course (death 7 weeks after diagnosis in patient 1). Patient 2 presented with a bifocal intracardial tumor without metastases and remains in complete remission for 46 months since diagnosis following multimodal therapy. The second case demonstrates that even in a potentially futile clinical situation early and accurate diagnosis followed by prompt and intensive multimodal therapy may offer prolonged survival, potential cure and improved quality of life.
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http://dx.doi.org/10.1016/j.cancergen.2014.04.005DOI Listing
September 2014

Virus and autoantigen-specific CD4+ T cells are key effectors in a SCID mouse model of EBV-associated post-transplant lymphoproliferative disorders.

PLoS Pathog 2014 May 22;10(5):e1004068. Epub 2014 May 22.

Clinical Cooperation Group Pediatric Tumor Immunology, Children's Hospital, Technische Universität München, Munich, Germany; Helmholtz Zentrum München, Munich, Germany; German Centre for Infection Research (DZIF), Munich, Germany.

Polyclonal Epstein-Barr virus (EBV)-infected B cell line (lymphoblastoid cell lines; LCL)-stimulated T-cell preparations have been successfully used to treat EBV-positive post-transplant lymphoproliferative disorders (PTLD) in transplant recipients, but function and specificity of the CD4+ component are still poorly defined. Here, we assessed the tumor-protective potential of different CD4+ T-cell specificities in a PTLD-SCID mouse model. Injection of different virus-specific CD4+ T-cell clones showed that single specificities were capable of prolonging mouse survival and that the degree of tumor protection directly correlated with recognition of target cells in vitro. Surprisingly, some CD4+ T-cell clones promoted tumor development, suggesting that besides antigen recognition, still elusive functional differences exist among virus-specific T cells. Of several EBV-specific CD4+ T-cell clones tested, those directed against virion antigens proved most tumor-protective. However, enriching these specificities in LCL-stimulated preparations conferred no additional survival benefit. Instead, CD4+ T cells specific for unknown, probably self-antigens were identified as principal antitumoral effectors in LCL-stimulated T-cell lines. These results indicate that virion and still unidentified cellular antigens are crucial targets of the CD4+ T-cell response in this preclinical PTLD-model and that enriching the corresponding T-cell specificities in therapeutic preparations may enhance their clinical efficacy. Moreover, the expression in several EBV-negative B-cell lymphoma cell lines implies that these putative autoantigen(s) might also qualify as targets for T-cell-based immunotherapy of virus-negative B cell malignancies.
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http://dx.doi.org/10.1371/journal.ppat.1004068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4031221PMC
May 2014

Posttransplant lymphoproliferative disease after pediatric solid organ transplantation.

Clin Dev Immunol 2013 24;2013:814973. Epub 2013 Sep 24.

Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany ; Integrated Research and Treatment Center Transplantation, Hannover Medical School, 30625 Hannover, Germany.

Patients after solid organ transplantation (SOT) carry a substantially increased risk to develop malignant lymphomas. This is in part due to the immunosuppression required to maintain the function of the organ graft. Depending on the transplanted organ, up to 15% of pediatric transplant recipients acquire posttransplant lymphoproliferative disease (PTLD), and eventually 20% of those succumb to the disease. Early diagnosis of PTLD is often hampered by the unspecific symptoms and the difficult differential diagnosis, which includes atypical infections as well as graft rejection. Treatment of PTLD is limited by the high vulnerability towards antineoplastic chemotherapy in transplanted children. However, new treatment strategies and especially the introduction of the monoclonal anti-CD20 antibody rituximab have dramatically improved outcomes of PTLD. This review discusses risk factors for the development of PTLD in children, summarizes current approaches to therapy, and gives an outlook on developing new treatment modalities like targeted therapy with virus-specific T cells. Finally, monitoring strategies are evaluated.
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http://dx.doi.org/10.1155/2013/814973DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3794558PMC
June 2014

Glucocorticoids augment survival and proliferation of tumor cells.

Anticancer Res 2012 Oct;32(10):4251-61

Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany.

Background: Glucocorticoids are widely used for cancer patients, although they can reduce the efficacy of anticancer treatment.

Materials And Methods: We characterized non-apoptotic actions of glucocorticoids on tumor cell lines, primary tumor cells and an in vivo model, together with molecular signaling studies.

Results: Glucocorticoids enhanced cell proliferation in 9/17 cell lines and significantly promoted tumor cell proliferation in a pre-clinical mouse model of lung carcinoma. 65/139 primary acute childhood leukemia samples were glucocorticoid-resistant. Both dexamethasone and prednisolone increased in vitro survival in 21/65 samples from glucocorticoid-resistant primary leukemias, revealing a completely new action of glucocorticoids. Dexamethasone-induced proliferation was mediated by glucocorticoid receptor and activated the proliferation signaling pathways of protein kinase B/AKT and p38 mitogen-activated protein kinase.

Conclusion: Our data suggest that restriction of the use of glucocorticoids during anticancer treatment might improve the outcome of patients with solid tumors.
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October 2012

Mature proteins derived from Epstein-Barr virus fail to feed into the MHC class I antigenic pool.

Eur J Immunol 2012 Dec 16;42(12):3167-73. Epub 2012 Oct 16.

Clinical Cooperation Group Pediatric Tumor Immunology, Helmholtz-Zentrum München, München, Germany.

The immediate presentation of peptide epitopes on MHC class I (MHC I) after antigen expression has led to the concept that MHC I ligands are mostly derived from defective ribosomal products (DRiPs), a subset of newly synthesized proteins that are rapidly degraded by the proteasome. Whether and to what extent mature proteins contribute to the antigenic pool, however, has remained elusive. Here, we developed a conditional antigen expression system that allows studying antigen presentation from mature proteins by inducing their rapid proteasomal degradation in the absence of further antigen synthesis. Target cells in which expression of two Epstein-Barr virus (EBV) antigens was induced were rapidly recognized by antigen-specific CD8(+) T cells in a time- and dosage-dependent manner, demonstrating that antigen presentation was linked to antigen synthesis. By contrast, T cells failed to recognize target cells containing large amounts of mature protein even after induction of their rapid proteasomal degradation. Thus, the presentation of these antigens proved to be strictly dependent on protein synthesis whereas mature proteins failed to furnish the antigenic pool. These results have implications for the design of immunotherapeutic strategies that aim at targeting proteins with increased half-lives and are hence overexpressed in tumors.
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http://dx.doi.org/10.1002/eji.201242627DOI Listing
December 2012
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