Publications by authors named "Nicolas Fischer"

59 Publications

Teratomatous Elements in Orchiectomy Specimens Are Associated with a Reduced Relapse-Free Survival in Metastasized Testicular Germ Cell Tumors.

Urol Int 2021 Jun 15:1-7. Epub 2021 Jun 15.

Department of Urology, Uro-Oncology, Robot Assisted and Reconstructive Urologic Surgery, University Hospital Cologne, Cologne, Germany.

Introduction: The impact of teratomatous elements in orchiectomy specimens of metastasized testicular germ cell tumors (TGCT) regarding oncological outcome is still unclear.

Methods: We performed a retrospective analysis including 146 patients with metastasized TGCT analysing patient characteristics.

Results: Twenty-six (18%) of all patients showed teratomatous elements in the orchiectomy specimens. TGCT with teratomatous elements showed a significantly higher frequency of clinical-stage 2C-3 disease (73 vs. 49%, p = 0.031), visceral metastases (58 vs. 32%, p = 0.015), and poor prognosis (p = 0.011) than TGCT without teratomatous elements. Teratoma-containing TGCT revealed a significantly higher rate of post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND, 54 vs. 32%, p = 0.041), with teratomatous elements being more often present in the PC-RPLND specimens (43 vs. 11%, p = 0.020) than nonteratoma-containing primaries. In the Kaplan-Meier estimates, the presence of teratomatous elements in orchiectomy specimens was associated with a significantly reduced relapse-free survival (RFS) (p = 0.049) during a median follow-up of 36 months (10-115.5).

Conclusions: The presence of teratomatous elements in orchiectomy specimens is associated with an advanced tumor stage, worse treatment response as well as a reduced RFS in metastasized TGCT. Consequently, the presence of teratomatous elements might act as a reliable stratification tool for treatment decision in TGCT patients.
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http://dx.doi.org/10.1159/000515715DOI Listing
June 2021

Deep Learning Based Instance Segmentation of Titanium Dioxide Particles in the Form of Agglomerates in Scanning Electron Microscopy.

Nanomaterials (Basel) 2021 Apr 9;11(4). Epub 2021 Apr 9.

Data Science and Uncertainty Department, National Laboratory of Metrology and Testing, 29 Avenue Roger Hennequin, 78197 Trappes, France.

The size characterization of particles present in the form of agglomerates in images measured by scanning electron microscopy (SEM) requires a powerful image segmentation tool in order to properly define the boundaries of each particle. In this work, we propose to use an algorithm from the deep statistical learning community, the Mask-RCNN, coupled with transfer learning to overcome the problem of generalization of the commonly used image processing methods such as watershed or active contour. Indeed, the adjustment of the parameters of these algorithms is almost systematically necessary and slows down the automation of the processing chain. The Mask-RCNN is adapted here to the case study and we present results obtained on titanium dioxide samples (non-spherical particles) with a level of performance evaluated by different metrics such as the DICE coefficient, which reaches an average value of 0.95 on the test images.
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http://dx.doi.org/10.3390/nano11040968DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8068950PMC
April 2021

A novel ligand of the translationally controlled tumor protein (TCTP) identified by virtual drug screening for cancer differentiation therapy.

Invest New Drugs 2021 Aug 25;39(4):914-927. Epub 2021 Jan 25.

Department of Pharmaceutical Biology, Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Staudinger Weg 5, 55128, Mainz, Germany.

Introduction Differentiation therapy is a promising strategy for cancer treatment. The translationally controlled tumor protein (TCTP) is an encouraging target in this context. By now, this field of research is still at its infancy, which motivated us to perform a large-scale screening for the identification of novel ligands of TCTP. We studied the binding mode and the effect of TCTP blockade on the cell cycle in different cancer cell lines. Methods Based on the ZINC-database, we performed virtual screening of 2,556,750 compounds to analyze the binding of small molecules to TCTP. The in silico results were confirmed by microscale thermophoresis. The effect of the new ligand molecules was investigated on cancer cell survival, flow cytometric cell cycle analysis and protein expression by Western blotting and co-immunoprecipitation in MOLT-4, MDA-MB-231, SK-OV-3 and MCF-7 cells. Results Large-scale virtual screening by PyRx combined with molecular docking by AutoDock4 revealed five candidate compounds. By microscale thermophoresis, ZINC10157406 (6-(4-fluorophenyl)-2-[(8-methoxy-4-methyl-2-quinazolinyl)amino]-4(3H)-pyrimidinone) was identified as TCTP ligand with a K of 0.87 ± 0.38. ZINC10157406 revealed growth inhibitory effects and caused G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. ZINC10157406 (2 × IC50) downregulated TCTP expression by 86.70 ± 0.44% and upregulated p53 expression by 177.60 ± 12.46%. We validated ZINC10157406 binding to the p53 interaction site of TCTP and replacing p53 by co-immunoprecipitation. Discussion ZINC10157406 was identified as potent ligand of TCTP by in silico and in vitro methods. The compound bound to TCTP with a considerably higher affinity compared to artesunate as known TCTP inhibitor. We were able to demonstrate the effect of TCTP blockade at the p53 binding site, i.e. expression of TCTP decreased, whereas p53 expression increased. This effect was accompanied by a dose-dependent decrease of CDK2, CDK4, CDK, cyclin D1 and cyclin D3 causing a G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. Our findings are supposed to stimulate further research on TCTP-specific small molecules for differentiation therapy in oncology.
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http://dx.doi.org/10.1007/s10637-020-01042-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8280061PMC
August 2021

AMG900 as novel inhibitor of the translationally controlled tumor protein.

Chem Biol Interact 2021 Jan 28;334:109349. Epub 2020 Nov 28.

Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Staudinger Weg 5, 55128, Mainz, Germany. Electronic address:

Introduction: Cancer is one of the leading causes of death worldwide. Classical cytotoxic chemotherapy exerts high side effects and low tumor selectivity. Translationally controlled tumor protein (TCTP) is a target for differentiation therapy, a promising, new therapeutic approach, which is expected to be more selective and less toxic than cytotoxic chemotherapy. The aim of the present investigation was to identify novel TCTP inhibitors.

Methods: We performed in silico screening and molecular docking using a chemical library of more than 31,000 compounds to identify a novel inhibitor of TCTP. We tested AMG900 in vitro for binding to TCTP by microscale thermophoresis and co-immunoprecipitation. Additionally, we examined the effect of TCTP blockade on cell cycle progression by flow cytometry and Western blotting and cancer cell survival by resazurin assays in MCF-7, SK-OV3 and MOLT-4 cell lines.

Results: We identified AMG900 as new inhibitor of TCTP. AMG900 bound to the p53 binding site of TCTP with a free binding energy of -9.63 ± 0.01 kcal/mol. This compound decreased TCTP expression to 23.4 ± 1.59% and increased p53 expression to 194.29 ± 24.27%. Furthermore, AMG900 induced G0/G1 arrest as shown by flow cytometry and Western blot of relevant cell cycle proteins. AMG900 decreased CDK2, CDK4, CDK6, cyclin D1 and cyclin D3 expression, whereas p18, p21 and p27 expression increased. Moreover, AMG900 disturbed TCTP-p53 complexation as shown by co-immunoprecipitation and increased expression of free p53.

Discussion: AMG900 may serve as novel lead compound for the development of differentiation therapy approaches against cancer.
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http://dx.doi.org/10.1016/j.cbi.2020.109349DOI Listing
January 2021

Dual-Time Point [Ga]Ga-PSMA-11 PET/CT Hybrid Imaging for Staging and Restaging of Prostate Cancer.

Cancers (Basel) 2020 Sep 28;12(10). Epub 2020 Sep 28.

Clinic of Nuclear Medicine, Johannes Gutenberg-University, 55101 Mainz, Germany.

Routine [Ga]Ga-PSMA-11 PET/CT (one hour post-injection) has been shown to accurately detect prostate cancer (PCa) lesions. The goal of this study is to evaluate the benefit of a dual-time point imaging modality for the staging and restaging of PCa patients. Biphasic [Ga]Ga-PSMA-11 PET/CT of 233 patients, who underwent early and late scans (one/three hours post-injection), were retrospectively studied. Tumor uptake and biphasic lesion detection for 215 biochemically recurrent patients previously treated for localized PCa (prostatectomized patients (P-P)/irradiated patients (P-I) and 18 patients suspected of having primary PCa (P-T) were separately evaluated. Late [Ga]Ga-PSMA-11 PET/CT imaging detected 554 PCa lesions in 114 P-P patients, 187 PCa lesions in 33 P-I patients, and 47 PCa lesions in 13 P-T patients. Most patients (106+32 P-P/P-I, 13 P-T) showed no additional PCa lesions. However, 11 PSMA-avid lesions were only detected in delayed images, and 33 lesions were confirmed as malignant by a SUVmax increase. The mean SUVmax of pelvic lymph node metastases was 25% higher ( < 0.001) comparing early and late PET/CT. High positivity rates from routine [Ga]Ga-PSMA-11 PET/CT for the staging and restaging of PCa patients were demonstrated. There was no decisive influence of additional late imaging with PCa lesion detection on therapeutic decisions. However, in a few individual cases, additional delayed scans provided an information advantage in PCa lesion detection due to higher tracer uptake and improved contrast.
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http://dx.doi.org/10.3390/cancers12102788DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7600341PMC
September 2020

Impact of the COVID-19 Pandemic on Urologists in Germany.

Eur Urol Focus 2020 Sep 8;6(5):1111-1119. Epub 2020 Jun 8.

Department of Medicine III, University Hospital RWTH Aachen, Aachen, Germany.

Background: In order to contain the coronavirus disease 2019 (COVID-19) pandemic, Germany has implemented drastic restrictions on public or social life, while health institutions are invoked to postpone elective procedures. Although urologists are less involved in the direct treatment of COVID-19 patients, the current situation strongly affects the urological work routine.

Objective: To analyze the impact of the COVID-19 pandemic on various aspects of work and personal life among urologists in Germany.

Design, Setting, And Participants: A total of 589 urologists in Germany participated in an online survey between March 27 and April 11, 2020.

Outcome Measurements And Statistical Analysis: Participants were stratified into subgroups according to professional characteristics.

Results And Limitations: Most urologists rated Germany as "well prepared" and the increasing restrictions of social life as "very positive." Routine operation was more restricted in hospitals than in the outpatient sector (p = 0.046). Moreover, urologists from the outpatient sector felt significantly less prepared for the COVID-19 pandemic (p = 0.001), reported a higher shortage of protective medical equipment (p < 0.001), and described a tendency toward a higher level of threat (p = 0.054). Although restrictions regarding telemedicine approaches were reported by 60% of participants, the outpatient sector used telehealth more frequently than hospitals (25.5% vs 17.0%, p < 0.001). Limitations include the national design and the restricted survey period.

Conclusions: This survey systematically evaluates the impact of the COVID-19 pandemic on personal and professional aspects of German urologists. We identified several issues, such as a higher shortage of medical protective equipment in the outpatient sector that could trigger specific measures to further improve the quality of urological care in Germany.

Patient Summary: We evaluated a potential impact of the coronavirus disease 2019 (COVID-19) pandemic on professional and personal aspects of the urologists in Germany. Our results suggest that the outpatient sector should receive specific attention as, for example, shortage of protective equipment was more common.
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http://dx.doi.org/10.1016/j.euf.2020.06.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7834409PMC
September 2020

PSA and PSA Kinetics Thresholds for the Presence of Ga-PSMA-11 PET/CT-Detectable Lesions in Patients With Biochemical Recurrent Prostate Cancer.

Cancers (Basel) 2020 Feb 8;12(2). Epub 2020 Feb 8.

Clinic of Nuclear Medicine, Johannes Gutenberg-University, 55101 Mainz, Germany.

Ga-PSMA-11 positron-emission tomography/computed tomography (PET/CT) is commonly used for restaging recurrent prostate cancer (PC) in European clinical practice. The goal of this study is to determine the optimum time for performing these PET/CT scans in a large cohort of patients by identifying the prostate-specific-antigen (PSA) and PSA kinetics thresholds for detecting and localizing recurrent PC. This retrospective analysis includes 581 patients with biochemical recurrence (BC) by definition. The performance of Ga-PSMA-11 PET/CT in relation to the PSA value at the scan time as well as PSA kinetics was assessed by the receiver-operating-characteristic-curve (ROC) generated by plotting sensitivity versus 1-specificity. Malignant prostatic lesions were identified in 77%. For patients that were treated with radical prostatectomy (RP) a PSA value of 1.24 ng/mL was found to be the optimal cutoff level for predicting positive and negative scans, while for patients previously treated with radiotherapy (RT) it was 5.75 ng/mL. In RP-patients with PSA value <1.24 ng/mL, 52% scans were positive, whereas patients with PSA ≥1.24 ng/mL had positive scan results in 87%. RT-patients with PSA <5.75 ng/mL had positive scans in 86% and and for those with PSA ≥5.75 ng/mL 94% had positive scans. This study identifies the PSA and PSA kinetics threshold levels for the presence of Ga-PSMA-11 PET/CT-detectable PC-lesions in BC patients.
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http://dx.doi.org/10.3390/cancers12020398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7072299PMC
February 2020

Effect of glucose and insulin supplementation on the isolation of primary human hepatocytes.

EXCLI J 2019 18;18:1071-1091. Epub 2019 Nov 18.

Department of Hepatobiliary Surgery and Visceral Transplantation, University Hospital, Leipzig University, Leipzig, Germany.

Primary human hepatocytes (PHHs) remain the gold standard for investigations of xenobiotic metabolism and hepatotoxicity. However, scarcity of liver tissue and novel developments in liver surgery has limited the availability and quality of tissue samples. In particular, warm ischemia shifts the intracellular metabolism from aerobic to anaerobic conditions, which increases glycogenolysis, glucose depletion and energy deficiency. Therefore, the aim of the present study was to investigate whether supplementation with glucose and insulin during PHH isolation could reconstitute intracellular glycogen storage and beneficially affect viability and functionality. Furthermore, the study elucidated whether the susceptibility of the tissue's energy status correlates with body mass index (BMI). PHHs from 12 donors were isolated from human liver tissue obtained from partial liver resections using a two-step EDTA/collagenase perfusion technique. For a direct comparison of the influence of glucose/insulin supplementation, we modified the setup, enabling the parallel isolation of two pieces of one tissue sample with varying perfusate. Independent of the BMI of the patient, the glycogen content in liver tissue was notably low in the majority of samples. Furthermore, supplementation with glucose and insulin had no beneficial effect on the glycogen concentration of isolated PHHs. However, an indirect improvement of the availability of energy was shown by increased viability, plating efficiency and partial cellular activity after supplementation. The plating efficiency showed a striking inverse correlation with increasing lipid content of PHHs. However, 60 h of cultivation time revealed no significant impact on the maintenance of albumin and urea synthesis or xenobiotic metabolism after supplementation. In conclusion, surgical procedures and tissue handling may decrease hepatic energy resources and lead to cell stress and death. Consequently, PHHs with low energy resources die during the isolation process without supplementation of glucose/insulin or early cell culture, while their survival rates are improved with glucose/insulin supplementation.
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http://dx.doi.org/10.17179/excli2019-1782DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6909377PMC
November 2019

Tuning Relative Polypeptide Expression to Optimize Assembly, Yield and Downstream Processing of Bispecific Antibodies.

Antibodies (Basel) 2018 Aug 10;7(3). Epub 2018 Aug 10.

Novimmune SA, 14 Chemin des Aulx, 1228 Plan-les-Ouates, Switzerland.

Bispecific antibodies (bsAbs) are often composed of several polypeptide chains that have to be expressed adequately to enable optimal assembly and yield of the bsAb. κλ bodies are a bispecific format with a native IgG structure, composed of two different light chains that pair with a common heavy chain. Introduction of non-optimal codons into the sequence of a particular polypeptide is an effective strategy for down modulating its expression. Here we applied this strategy but restricted the modification of the codon content to the constant domain of one light chain. This approach facilitates parallel optimization of several bsAbs by using the same modified constant domains. Partial sequence de-optimization reduced expression of the targeted polypeptide. Stable cell pools could be isolated displaying increased bispecific antibody titers as well as changes in the abundance of undesired by-products that require elimination during downstream processing. Thus, modulating the relative expression of polypeptides can have a significant impact on bsAb titer and product related impurities; which are important factors for large scale manufacturing for clinical supply.
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http://dx.doi.org/10.3390/antib7030029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6640677PMC
August 2018

Radiation Dose in Prostatic Artery Embolization Using Cone-Beam CT and 3D Roadmap Software.

J Vasc Interv Radiol 2019 Sep 29;30(9):1452-1458. Epub 2019 Jul 29.

Institut für Diagnostische und Interventionelle Radiologie, Helios Klinikum Krefeld, Lutherplatz 40, 47805 Krefeld, Germany.

Purpose: To evaluate the radiation dose in patients undergoing prostatic artery embolization (PAE) using cone-beam CT and 3-dimensional (3D) guidance software.

Materials And Methods: In this single-center retrospective study, 100 patients with benign prostatic hyperplasia (mean prostate volume, 83.6 mL ± 44.2; 69.4 ± 9.6 years of age; body mass index, 26.5 ± 4.2) were treated using PAE between October 2016 and April 2018. Informed consent was obtained from all participants included in the study. All patients received at least 1 intraprocedural cone-beam CT per side for evaluation of the vessel anatomy and software rendering of 3D guidance for catheter guidance. Digital subtraction angiography (DSA) was performed in the distal branches only. The total dose area product (DAP), along with the DAP attributed to fluoroscopy, DSA, and cone-beam CT, were assessed.

Results: Bilateral embolization was achieved in 83 patients (83%). The average total DAP was 134.4 Gy ⋅ cm ± 69.5 (range, 44.7-410.9 Gy ⋅ cm). Fluoroscopy, DSA, and cone-beam CT accounted for 35.5 Gy ⋅ cm ± 21.3 (range, 8.6-148.6 Gy ⋅ cm) or 26.4% (percentage of total DAP), 58.2 Gy ⋅ cm ± 48.3 (range, 10.3-309.3 Gy ⋅ cm) or 43.3%, and 40.7 Gy ⋅ cm ± 14.5 (range, 15.9-86.3 Gy ⋅ cm) or 30.3%, respectively. Average procedure time was 89.4 ± 27.0 minutes, and the average fluoroscopy time was 30.9 ± 12.2 minutes.

Conclusions: Intraprocedural cone-beam CT in combination with 3D guidance software allows for identification and catheterization of the prostatic artery in PAE. Furthermore, the results of this trial indicate that this study protocol may lead to a low overall radiation dose.
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http://dx.doi.org/10.1016/j.jvir.2019.04.040DOI Listing
September 2019

Biopiracy versus One-World Medicine-From colonial relicts to global collaborative concepts.

Phytomedicine 2019 Feb 11;53:319-331. Epub 2018 Jun 11.

Department of Chemistry, University of Nairobi, Nairobi, Kenya.

Background: Practices of biopiracy to use genetic resources and indigenous knowledge by Western companies without benefit-sharing of those, who generated the traditional knowledge, can be understood as form of neocolonialism.

Hypothesis: The One-World Medicine concept attempts to merge the best of traditional medicine from developing countries and conventional Western medicine for the sake of patients around the globe.

Study Design: Based on literature searches in several databases, a concept paper has been written. Legislative initiatives of the United Nations culminated in the Nagoya protocol aim to protect traditional knowledge and regulate benefit-sharing with indigenous communities. The European community adopted the Nagoya protocol, and the corresponding regulations will be implemented into national legislation among the member states. Despite pleasing progress, infrastructural problems of the health care systems in developing countries still remain. Current approaches to secure primary health care offer only fragmentary solutions at best. Conventional medicine from industrialized countries cannot be afforded by the impoverished population in the Third World. Confronted with exploding costs, even health systems in Western countries are endangered to burst. Complementary and alternative medicine (CAM) is popular among the general public in industrialized countries, although the efficacy is not sufficiently proven according to the standards of evidence-based medicine. CAM is often available without prescription as over-the-counter products with non-calculated risks concerning erroneous self-medication and safety/toxicity issues. The concept of integrative medicine attempts to combine holistic CAM approaches with evidence-based principles of conventional medicine.

Conclusion: To realize the concept of One-World Medicine, a number of standards have to be set to assure safety, efficacy and applicability of traditional medicine, e.g. sustainable production and quality control of herbal products, performance of placebo-controlled, double-blind, randomized clinical trials, phytovigilance, as well as education of health professionals and patients.
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http://dx.doi.org/10.1016/j.phymed.2018.06.007DOI Listing
February 2019

Prevention from radiation damage by natural products.

Phytomedicine 2018 Aug 13;47:192-200. Epub 2017 Nov 13.

Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany. Electronic address:

Background: Radiotherapy is a mainstay of cancer treatment since decades. Ionizing radiation (IR) is used for destruction of cancer cells and shrinkage of tumors. However, the increase of radioresistance in cancer cells and radiation toxicity to normal tissues are severe concerns. The exposure to radiation generates intracellular reactive oxygen species (ROS), which leads to DNA damage by lipid peroxidation, removal of thiol groups from cellular and membrane proteins, strand breaks and base alterations.

Hypothesis: Plants have to deal with radiation-induced damage (UV-light of sun, other natural radiation sources). Therefore, it is worth speculating that radioprotective mechanisms have evolved during evolution of life. We hypothesize that natural products from plants may also protect from radiation damage caused as adverse side effects of cancer radiotherapy.

Methods: The basis of this systematic review, we searched the relevant literature in the PubMed database.

Results: Flavonoids, such as genistein, epigallocatechin-3-gallate, epicatechin, apigenin and silibinin mainly act as antioxidant, free radical scavenging and anti-inflammatory compounds, thus, providing cytoprotection in addition to downregulation of several pro-inflammatory cytokines. Comparable effects have been found in phenylpropanoids, especially caffeic acid phenylethylester, curcumin, thymol and zingerone. Besides, resveratrol and quercetin are the most important cytoprotective polyphenols. Their radioprotective effects are mediated by a wide range of mechanisms mainly leading to direct or indirect reduction of cellular stress. Ascorbic acid is broadly used as antioxidant, but it has also shown activity in reducing cellular damage after irradiation mainly due to its antioxidant capabilities. The metal ion chelator, gallic acid, represents another natural product attenuating cellular damage caused by radiation.

Conclusions: Some secondary metabolites from plants reveal radioprotective features against cellular damage caused by irradiation. These results warrant further analysis to develop phytochemicals as radioprotectors for clinical use.
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http://dx.doi.org/10.1016/j.phymed.2017.11.005DOI Listing
August 2018

Replicability of Physical Exercise Interventions in Lung Transplant Recipients; A Systematic Review.

Front Physiol 2018 20;9:946. Epub 2018 Jul 20.

Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland.

This systematic review aimed to assess the replicability of physical exercise interventions in lung transplantation patients. For replicability we focused on (1) the description of training principles, (2) the description of FITT components and adherence to the interventions, (3) the amount of detailed information given on the physical exercise intervention, and (4) reporting the methodological quality of the included works. Relevant databases (Medline-Ovid, EMBASE, CINAHL, PsychInfo, Cochrane Library) were searched. Author dyads selected and systematically analyzed the included studies independent from each other. A purpose developed checklist was used to assess the details of the exercise interventions and their methodological quality. From the seven included manuscripts, three described resistance training, one endurance, and three combined training approaches. All manuscripts reported specificity and initial values, six manuscripts mention progression and overload. The exercise principle reversibility was reported once and diminishing returns was not reported at all. All studies reported the type of exercise, three studies reported intensity and one study reported time for training. Not any study completely reported frequency or described adherence to the intervention. Lack of detailed reporting was identified as the cause for murky description of the interventions. The highest score for intervention description was 5 of possible 12 items. Replicability of many exercise interventions in LTX is not warranted due too poor descriptions of important items related to training. In particular there were insufficiently detailed reporting of training principles and FITT components in programs developed for LTX. Future interventions that aim to train LTX patients should spent effort in writing reports in which the intervention is detailed to such an extent that full replicability in clinical settings can be guaranteed.
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http://dx.doi.org/10.3389/fphys.2018.00946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6062962PMC
July 2018

Ureterorenoskopisch unterstützte Embolisation einer venösen Kalyxfistel der Niere. Ein alternativer Zugangsweg.

Rofo 2018 Dec 6;190(12):1159-1161. Epub 2018 Jun 6.

Department of Diagnostic and Interventional Radiology, HELIOS-Klinikum Krefeld, Germany.

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http://dx.doi.org/10.1055/a-0631-4813DOI Listing
December 2018

Preclinical Development of a Bispecific Antibody that Safely and Effectively Targets CD19 and CD47 for the Treatment of B-Cell Lymphoma and Leukemia.

Mol Cancer Ther 2018 08 9;17(8):1739-1751. Epub 2018 May 9.

Novimmune S.A., Plan-les-Ouates, Switzerland.

CD47, an ubiquitously expressed innate immune checkpoint receptor that serves as a universal "don't eat me" signal of phagocytosis, is often upregulated by hematologic and solid cancers to evade immune surveillance. Development of CD47-targeted modalities is hindered by the ubiquitous expression of the target, often leading to rapid drug elimination and hemotoxicity including anemia. To overcome such liabilities, we have developed a fully human bispecific antibody, NI-1701, designed to coengage CD47 and CD19 selectively on B cells. NI-1701 demonstrates favorable elimination kinetics with no deleterious effects seen on hematologic parameters following single or multiple administrations to nonhuman primates. Potent and activity is induced by NI-1701 to kill cancer cells across a plethora of B-cell malignancies and control tumor growth in xenograft mouse models. The mechanism affording maximal tumor growth inhibition by NI-1701 is dependent on the coengagement of CD47/CD19 on B cells inducing potent antibody-dependent cellular phagocytosis of the targeted cells. NI-1701-induced control of tumor growth in immunodeficient NOD/SCID mice was more effective than that achieved with the anti-CD20 targeted antibody, rituximab. Interestingly, a synergistic effect was seen when tumor-implanted mice were coadministered NI-1701 and rituximab leading to significantly improved tumor growth inhibition and regression in some animals. We describe herein, a novel bispecific antibody approach aimed at sensitizing B cells to become more readily phagocytosed and eliminated thus offering an alternative or adjunct therapeutic option to patients with B-cell malignancies refractory/resistant to anti-CD20-targeted therapy. .
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http://dx.doi.org/10.1158/1535-7163.MCT-17-1095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6072583PMC
August 2018

Stabilized Low-n Amyloid-β Oligomers Induce Robust Novel Object Recognition Deficits Associated with Inflammatory, Synaptic, and GABAergic Dysfunction in the Rat.

J Alzheimers Dis 2018 ;62(1):213-226

Division of Pharmacy and Optometry, University of Manchester, Manchester, UK.

Background: With current treatments for Alzheimer's disease (AD) only providing temporary symptomatic benefits, disease modifying drugs are urgently required. This approach relies on improved understanding of the early pathophysiology of AD. A new hypothesis has emerged, in which early memory loss is considered a synapse failure caused by soluble amyloid-β oligomers (Aβo). These small soluble Aβo, which precede the formation of larger fibrillar assemblies, may be the main cause of early AD pathologies.

Objective: The aim of the current study was to investigate the effect of acute administration of stabilized low-n amyloid-β1-42 oligomers (Aβo1-42) on cognitive, inflammatory, synaptic, and neuronal markers in the rat.

Methods: Female and male Lister Hooded rats received acute intracerebroventricular (ICV) administration of either vehicle or 5 nmol of Aβo1-42 (10μL). Cognition was assessed in the novel object recognition (NOR) paradigm at different time points. Levels of inflammatory (IL-1β, IL-6, TNF-α), synaptic (PSD-95, SNAP-25), and neuronal (n-acetylaspartate, parvalbumin-positive cells) markers were investigated in different brain regions (prefrontal and frontal cortex, striatum, dorsal and ventral hippocampus).

Results: Acute ICV administration of Aβo1-42 induced robust and enduring NOR deficits. These deficits were reversed by acute administration of donepezil and rolipram but not risperidone. Postmortem analysis revealed an increase in inflammatory markers, a decrease in synaptic markers and parvalbumin containing interneurons in the frontal cortex, with no evidence of widespread neuronal loss.

Conclusion: Taken together the results suggest that acute administration of soluble low-n Aβo may be a useful model to study the early mechanisms involved in AD and provide us with a platform for testing novel therapeutic approaches that target the early underlying synaptic pathology.
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http://dx.doi.org/10.3233/JAD-170489DOI Listing
March 2019

Tumor-Directed Blockade of CD47 with Bispecific Antibodies Induces Adaptive Antitumor Immunity.

Antibodies (Basel) 2018 Jan 3;7(1). Epub 2018 Jan 3.

Novimmune S.A., 14 chemin des Aulx, CH-1228 Geneva, Switzerland.

CD47 serves as an anti-phagocytic receptor that is upregulated by cancer to promote immune escape. As such, CD47 is the focus of intense immuno-oncology drug development efforts. However, as CD47 is expressed ubiquitously, clinical development of conventional drugs, e.g., monoclonal antibodies, is confronted with patient safety issues and poor pharmacology due to the widespread CD47 "antigen sink". A potential solution is tumor-directed blockade of CD47, which can be achieved with bispecific antibodies (biAbs). Using mouse CD47-blocking biAbs in a syngeneic tumor model allowed us to evaluate the efficacy of tumor-directed blockade of CD47 in the presence of the CD47 antigen sink and a functional adaptive immune system. We show here that CD47-targeting biAbs inhibited tumor growth in vivo, promoting durable antitumor responses and stimulating CD8 T cell activation in vitro. In vivo efficacy of the biAbs could be further enhanced when combined with chemotherapy or PD-1/PD-L1 immune checkpoint blockade. We also show that selectivity and pharmacological properties of the biAb are dependent on the affinity of the anti-CD47 arm. Taken together, our study validates the approach to use CD47-blocking biAbs either as a monotherapy or part of a multi-drug approach to enhance antitumor immunity.
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http://dx.doi.org/10.3390/antib7010003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6698848PMC
January 2018

Phytochemicals as inhibitors of NF-κB for treatment of Alzheimer's disease.

Pharmacol Res 2018 03 24;129:262-273. Epub 2017 Nov 24.

Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany. Electronic address:

Alzheimer's disease (AD) is the most prevalent form of dementia. The exact pathophysiology of this disease remains incompletely understood and safe and effective therapies are required. AD is highly correlated with neuroinflammation and oxidative stress in brain causing neuronal loss. Nuclear factor of activated B-cells (NF-κB) is involved in physiological inflammatory processes and thus representing a promising target for inflammation-based AD therapy. Phytochemicals are able to interfere with the NF-κB pathway. They inhibit the phosphorylation or the ubiquitination of signaling molecules, and thus, inhibit the degradation of IκB. The translocation of NF-κB to the nucleus and subsequent transcription of pro-inflammatory cytokines are inhibited by the actions of phytochemicals. Additionally, natural compounds preventing the interaction of NF-κB can block NF-κB's transcriptional activity by inhibiting its binding to target DNA. Many polyphenols including curcumin, resveratrol, pterostilbene, punicalagin, macranthoin G, salidroside, 4-O-methylhonokiol, lycopene, genistein, obovatol and gallic acid were reported as potent NF-κB inhibitors for AD treatment. Several alkaloids such as galantamine, glaucocalyxin B, tetrandrine, berberine, oridonin, anatabine have been shown anti-inflammatory effects in AD models in vitro as well as in vivo. Besides, vitamins, tanshinone IIA, artemisinin, dihydroasparagusic acid, geniposide, xanthoceraside, l-theranine, 1,8-cineole and paeoniflorin were described as promising NF-κB inhibitors. In conclusion, natural products from plants represent interesting candidates for AD treatment. They may qualify as promising compounds for the development of derivatives providing enhanced pharmacological features.
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http://dx.doi.org/10.1016/j.phrs.2017.11.030DOI Listing
March 2018

Role of TCTP for Cellular Differentiation and Cancer Therapy.

Results Probl Cell Differ 2017;64:263-281

Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128, Mainz, Germany.

The translationally controlled tumor protein (TCTP) is a highly conserved protein that is regulated due to a high number of extracellular stimuli. TCTP has an important role for cell cycle and normal development. On the other side, tumor reversion and malignant transformation have been associated with TCTP. TCTP has been found among the 12 genes that are differentially expressed during mouse oocyte maturation, and an overexpression of this gene was reported in a wide variety of different cancer types. Its antiapoptotic effect is indicated by the interaction with several proapoptotic proteins of the Bcl-2 family and the p53 tumor suppressor protein. In this article, we draw attention to the role of TCTP in cancer, especially, focusing on cell differentiation and tumor reversion, a biological process by which highly tumorigenic cells lose their malignant phenotype. This protein has been shown to be the most strongly downregulated protein in revertant cells compared to the parental cancer cells. Decreased expression of TCTP results either in the reprogramming of cancer cells into reversion or apoptosis. As conventional chemotherapy is frequently associated with the development of drug resistance and high toxicity, the urge for the development of new or additional scientific approaches falls into place. Differentiation therapy aims at reinducing differentiation backward to the nonmalignant cellular state. Here, different approaches have been reported such as the induction of retinoid pathways and the use of histone deacetylase inhibitors. Also, PPARγ agonists and the activation of the vitamin D receptor have been reported as potential targets in differentiation therapy. As TCTP is known as the histamine-releasing factor, antihistaminic drugs have been shown to target this protein. Antihistaminic compounds, hydroxyzine and promethazine, inhibited cell growth of cancer cells and decreased TCTP expression of breast cancer and leukemia cells. Recently, we found that two antihistaminics, levomepromazine and buclizine, inhibited cancer cell growth by direct binding to TCTP and induction of cell differentiation. These data confirmed that TCTP is an exquisite target for anticancer differentiation therapy and antihistaminics have potential to be lead compounds for the direct interaction with TCTP as new inhibitors of human TCTP and tumor growth.
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http://dx.doi.org/10.1007/978-3-319-67591-6_14DOI Listing
July 2019

Pharmacological and chemical features of Nepeta L. genus: Its importance as a therapeutic agent.

Phytother Res 2018 Feb 18;32(2):185-198. Epub 2017 Oct 18.

Institute of Pharmacy and Biochemistry, Johannes Gutenberg University of Mainz, Staudinger Weg 5, 55128, Mainz, Germany.

Medicinal plants have always had great value for the human population due to their valuable constituents and potential bioactivities. The objective of this review is to present an updated overview of an important medicinal plant genus Nepeta L., from the family Lamiaceae, revealing its traditional utilization, biological activity, phytoconstituents, and mechanisms of action. For this purpose, a literature survey was carried out by using SciFinder, ScienceDirect, Scopus, PubMed, and Web of Science followed by a revision of the bibliographies of the related articles. We have described and analyzed the role of plants in drug discovery and the importance of Nepeta species. Information on the utilization purposes of Nepeta species in folk medicine has been emphasized, and scientific studies on the biological effects and secondary metabolites are addressed. Nepeta species are characterized by terpenoid-type compounds and phenolic constituents, which exert several activities such as an antimicrobial, repellent against major pathogen vector mosquitoes, insecticide, larvicide against Anopheles stephensi, cytotoxic anticarcinogen, antioxidant, anticonvulsant, analgesic, anti-inflammatory agent, and antidepressant, revealing its importance in medicinal and agricultural fields. On the basis of numerous studies, the Nepeta genus demonstrates remarkable therapeutic effects against various diseases. However, clinical studies are warranted to confirm preclinical findings.
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http://dx.doi.org/10.1002/ptr.5946DOI Listing
February 2018

Dual display: phage selection driven by co-engagement of two targets by two different antibody fragments.

Protein Eng Des Sel 2017 09;30(9):575-582

Department of Pathology and Immunology, University of Geneva, Geneva, CH-1211, Switzerland.

Antibody phage display technology has supported the emergence of numerous therapeutic antibodies. The development of bispecific antibodies, a promising new frontier in antibody therapy, could be facilitated by new phage display approaches that enable pairs of antibodies to be co-selected based on co-engagement of their respective targets. We describe such an approach, making use of two complementary leucine zipper domains that heterodimerize with high affinity. Phagemids encoding a first antibody fragment (scFv) fused to phage coat protein via the first leucine zipper are rescued in bacteria expressing a second scFv fused to the second leucine zipper as a soluble periplasmic protein, so that it is acquired by phage during assembly. Using a soluble scFv specific for a human CD3-derived peptide, we show that its acquisition by phage displaying an irrelevant antibody is sufficiently robust to drive selection of rare phage (1 in 10(5)) over three rounds of panning. We then set up a model selection experiment using a cell line expressing the chemokine receptor CCR5 fused to the CD3 peptide together with a panel of phage clones capable displaying either an anti-CCR5 scFv or an irrelevant antibody, with or without the capacity to acquire the soluble anti-CD3 scFv. In this experiment we showed that rare phage (1 in 10(5)) capable of displaying the two different scFvs can be specifically enriched over four rounds of panning. This approach has the potential to be applied to the identification of pairs of ligands capable of co-engaging two different user-defined targets, which would facilitate the discovery of novel bispecific antibodies.
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http://dx.doi.org/10.1093/protein/gzx021DOI Listing
September 2017

Antibody Neutralization of CXCL10 Is Dependent on Binding to Free and Not Endothelial-bound Chemokine: IMPLICATIONS FOR THE DESIGN OF A NEW GENERATION OF ANTI-CHEMOKINE THERAPEUTIC ANTIBODIES.

J Biol Chem 2017 03 30;292(10):4185-4197. Epub 2017 Jan 30.

From Novimmune SA, chemin des Aulx 14, 1228 Plan-les-Ouates, Geneva, Switzerland,

To improve our understanding of properties that confer successful inhibition of chemokines , we analyzed anti-murine CXCL10 monoclonal antibodies (mAb) having different characteristics. 1B6 displayed potent inhibition of cell recruitment with an IC of 0.5 nm but demonstrated little efficacy in various animal models of human disease. On the contrary, 1F11 showed efficacy in several models of inflammation yet was less potent at inhibiting chemotaxis with an IC of 21 nm Furthermore, we observed that 1B6 displayed a rapid dose-dependent clearance ( 10-60 h) in contrast to 1F11, which presented a dose-proportional pharmacokinetic profile and a half-life of 12 days. Moreover, 1B6 recognized glycosaminoglycan (GAG)-bound CXCL10, resulting in target-mediated clearance, which was corroborated using CXCL10-deficient mice. In contrast to 1B6, 1F11 inhibited the interaction of CXCL10 with GAGs, did not recognize GAG-bound CXCL10, and did not display target-mediated drug disposition. Confirming previous animal studies, 1B6 was poor at reversing glycemia in a model of type 1 diabetes, whereas 1F11 induced early and prolonged control of diabetes. Furthermore, when using 1A4, a subsequently generated anti-mCXCL10 mAb that shares the property with 1F11 of being unable to recognize CXCL10 immobilized on GAG, we observed a similar superior control of diabetes as compared with 1B6. We therefore concluded that targeting chemokines with antibodies such as 1B6 that recognize the more abundant GAG-bound form of the chemokine may not be the optimal strategy to achieve disease control.
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http://dx.doi.org/10.1074/jbc.M116.745877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5354510PMC
March 2017

Selective Blockade of the Ubiquitous Checkpoint Receptor CD47 Is Enabled by Dual-Targeting Bispecific Antibodies.

Mol Ther 2017 02;25(2):523-533

Novimmune SA, 14 chemin des Aulx, 1228 Plan-les-Ouates, Switzerland. Electronic address:

CD47 is a ubiquitously expressed immune checkpoint receptor that is often upregulated in cancer. CD47 interacts with its counter-receptor SIRPα on macrophages and other myeloid cells to inhibit cancer cell phagocytosis and drive immune evasion. To overcome tolerability and "antigen sink" issues arising from widespread CD47 expression, we generated dual-targeting bispecific antibodies that selectively block the CD47-SIRPα interaction on malignant cells expressing a specific tumor-associated antigen; e.g., CD19 or mesothelin. These bispecific κλ bodies are fully human, native IgG1 molecules, combining tumor targeting and selective CD47 blockade with immune activating mechanisms mediated by the Fc portion of the antibody. CD47-neutralizing κλ bodies efficiently kill cancer cells in vitro and in vivo but interact only weakly with healthy cells expressing physiological levels of CD47. Accordingly, a κλ body administered to non-human primates showed a typical IgG pharmacokinetic profile and was well tolerated. Importantly, κλ bodies preserve their tumoricidal capabilities in the presence of a CD47 antigen sink. Thus, dual-targeting κλ bodies allow for efficacious yet safe targeting of CD47 in cancer. Such a bispecific design could be applied to limit the extent of neutralization of other ubiquitously expressed therapeutic targets.
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http://dx.doi.org/10.1016/j.ymthe.2016.11.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5368402PMC
February 2017

Optimizing assembly and production of native bispecific antibodies by codon de-optimization.

MAbs 2017 Feb/Mar;9(2):231-239

a Novimmune SA , Plan-les-Ouates , Geneva , Switzerland.

When production of bispecific antibodies requires the co-expression and assembly of three or four polypeptide chains, low expression of one chain can significantly limit assembly and yield. κλ bodies, fully human bispecific antibodies with native IgG structure, are composed of a common heavy chain and two different light chains, one kappa and one lambda. No engineering is applied to force pairing of the chains, thus both monospecific and bispecific antibodies are secreted in the supernatant. In this context, stoichiometric expression of the two light chains allows for maximal assembly of the bispecific antibody. In this study, we selected a κλ body with suboptimal characteristics due to low kappa chain expression. Codon optimization to increase expression of the kappa chain did not improve bispecific yield. Surprisingly, progressive introduction of non-optimal codons into the sequence of the lambda chain resulted in lowering its expression for an optimal tuning of the relative distribution of monospecific and bispecific antibodies. This codon de-optimization led to doubling of the κλ body yield. These results indicate that assembly of different proteins into a recombinant complex is an interconnected process and that reducing the expression of one polypeptide can actually increase the overall yield.
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http://dx.doi.org/10.1080/19420862.2016.1267088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5297534PMC
November 2017

Fenamate NSAIDs inhibit the NLRP3 inflammasome and protect against Alzheimer's disease in rodent models.

Nat Commun 2016 08 11;7:12504. Epub 2016 Aug 11.

Faculty of Biology, Medicine and Health, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK.

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase-1 (COX-1) and COX-2 enzymes. The NLRP3 inflammasome is a multi-protein complex responsible for the processing of the proinflammatory cytokine interleukin-1β and is implicated in many inflammatory diseases. Here we show that several clinically approved and widely used NSAIDs of the fenamate class are effective and selective inhibitors of the NLRP3 inflammasome via inhibition of the volume-regulated anion channel in macrophages, independently of COX enzymes. Flufenamic acid and mefenamic acid are efficacious in NLRP3-dependent rodent models of inflammation in air pouch and peritoneum. We also show therapeutic effects of fenamates using a model of amyloid beta induced memory loss and a transgenic mouse model of Alzheimer's disease. These data suggest that fenamate NSAIDs could be repurposed as NLRP3 inflammasome inhibitors and Alzheimer's disease therapeutics.
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http://dx.doi.org/10.1038/ncomms12504DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4987536PMC
August 2016

Divergent JAM-C Expression Accelerates Monocyte-Derived Cell Exit from Atherosclerotic Plaques.

PLoS One 2016 21;11(7):e0159679. Epub 2016 Jul 21.

Department of Pathology and Immunology, CMU, University of Geneva, 1211, rue Michel Servet 1, Geneva 4, Switzerland.

Atherosclerosis, caused in part by monocytes in plaques, continues to be a disease that afflicts the modern world. Whilst significant steps have been made in treating this chronic inflammatory disease, questions remain on how to prevent monocyte and macrophage accumulation in atherosclerotic plaques. Junctional Adhesion Molecule C (JAM-C) expressed by vascular endothelium directs monocyte transendothelial migration in a unidirectional manner leading to increased inflammation. Here we show that interfering with JAM-C allows reverse-transendothelial migration of monocyte-derived cells, opening the way back out of the inflamed environment. To study the role of JAM-C in plaque regression we used a mouse model of atherosclerosis, and tested the impact of vascular JAM-C expression levels on monocyte reverse transendothelial migration using human cells. Studies in-vitro under inflammatory conditions revealed that overexpression or gene silencing of JAM-C in human endothelium exposed to flow resulted in higher rates of monocyte reverse-transendothelial migration, similar to antibody blockade. We then transplanted atherosclerotic, plaque-containing aortic arches from hyperlipidemic ApoE-/- mice into wild-type normolipidemic recipient mice. JAM-C blockade in the recipients induced greater emigration of monocyte-derived cells and further diminished the size of atherosclerotic plaques. Our findings have shown that JAM-C forms a one-way vascular barrier for leukocyte transendothelial migration only when present at homeostatic copy numbers. We have also shown that blocking JAM-C can reduce the number of atherogenic monocytes/macrophages in plaques by emigration, providing a novel therapeutic strategy for chronic inflammatory pathologies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0159679PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4956249PMC
July 2017

Bile canaliculi formation and biliary transport in 3D sandwich-cultured hepatocytes in dependence of the extracellular matrix composition.

Arch Toxicol 2016 Oct 21;90(10):2497-511. Epub 2016 Jun 21.

Department of General-, Visceral- and Transplantation Surgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.

Primary human hepatocytes (PHH) are still considered as gold standard for investigation of in vitro metabolism and hepatotoxicity in pharmaceutical research. It has been shown that the three-dimensional (3D) cultivation of PHH in a sandwich configuration between two layers of extracellular matrix (ECM) enables the hepatocytes to adhere three dimensionally leading to formation of in vivo like cell-cell contacts and cell-matrix interactions. The aim of the present study was to investigate the influence of different ECM compositions on morphology, cellular arrangement and bile canaliculi formation as well as bile excretion processes in PHH sandwich cultures systematically. Freshly isolated PHH were cultured for 6 days between two ECM layers made of collagen and/or Matrigel in four different combinations. The cultures were investigated by phase contrast microscopy and immunofluorescence analysis with respect to cell-cell connections, repolarization as well as bile canaliculi formation. The influence of the ECM composition on cell activity and viability was measured using the XTT assay and a fluorescent dead or alive assay. Finally, the bile canalicular transport was analyzed by live cell imaging to monitor the secretion and accumulation of the fluorescent substance CDF in bile canaliculi. Using collagen and Matrigel in different compositions in sandwich cultures of hepatocytes, we observed differences in morphology, cellular arrangement and cell activity of PHH in dependence of the ECM composition. Sandwich-cultured hepatocytes with an underlay of collagen seem to represent the best in vivo tissue architecture in terms of formation of trabecular cell arrangement. Cultures overlaid with collagen were characterized by the formation of abundant bile canaliculi, while the bile canaliculi network in hepatocytes cultured on a layer of Matrigel and overlaid with collagen showed the most branched and stable canalicular network. All cultures showed a time-dependent leakage of CDF from the bile canaliculi into the culture supernatant with variations in dependence on the used matrix combination. In conclusion, the results of this study show that the choice of ECM has an impact on the morphology, cell assembly and bile canaliculi formation in PHH sandwich cultures. The morphology and the multicellular arrangement were essentially influenced by the underlaying matrix, while bile excretion and leakage of sandwich-cultured hepatocytes were mainly influenced by the overlay matrix. Leaking and damaged bile canaliculi could be a limitation of the investigated sandwich culture models in long-term excretion studies.
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http://dx.doi.org/10.1007/s00204-016-1758-zDOI Listing
October 2016

Methods for the Recognition of GAG-Bound Chemokines.

Methods Enzymol 2016 8;570:73-85. Epub 2016 Feb 8.

NovImmune S.A., Geneva, Switzerland. Electronic address:

Chemokines play a pivotal role in the multistep cascade of cellular recruitment, where they provide the directional signal. They activate cells through a high-affinity interaction with their receptors, members of the large family of heptahelical G protein-coupled receptors. In order to provide the directional signal, they bind to cell surface proteoglycans through a low-affinity interaction with the glycosaminoglycan (GAG) moiety. While several methods have been described to measure the chemokine-GAG interaction, this chapter describes methods to identify whether anti-chemokine antibodies or chemokine-binding proteins recognize the GAG-bound chemokine.
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http://dx.doi.org/10.1016/bs.mie.2015.10.001DOI Listing
November 2017

Btn2a2, a T cell immunomodulatory molecule coregulated with MHC class II genes.

J Exp Med 2016 Feb 25;213(2):177-87. Epub 2016 Jan 25.

Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland

Evidence has recently emerged that butyrophilins, which are members of the extended B7 family of co-stimulatory molecules, have diverse functions in the immune system. We found that the human and mouse genes encoding butyrophilin-2A2 (BTN2A2) are regulated by the class II trans-activator and regulatory factor X, two transcription factors dedicated to major histocompatibility complex class II expression, suggesting a role in T cell immunity. To address this, we generated Btn2a2-deficient mice. Btn2a2(-/-) mice exhibited enhanced effector CD4(+) and CD8(+) T cell responses, impaired CD4(+) regulatory T cell induction, potentiated antitumor responses, and exacerbated experimental autoimmune encephalomyelitis. Altered immune responses were attributed to Btn2a2 deficiency in antigen-presenting cells rather than T cells or nonhematopoietic cells. These results provide the first genetic evidence that BTN2A2 is a co-inhibitory molecule that modulates T cell-mediated immunity.
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http://dx.doi.org/10.1084/jem.20150435DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4749920PMC
February 2016

Arenavirus Glycan Shield Promotes Neutralizing Antibody Evasion and Protracted Infection.

PLoS Pathog 2015 Nov 20;11(11):e1005276. Epub 2015 Nov 20.

Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.

Arenaviruses such as Lassa virus (LASV) can cause severe hemorrhagic fever in humans. As a major impediment to vaccine development, delayed and weak neutralizing antibody (nAb) responses represent a unifying characteristic of both natural infection and all vaccine candidates tested to date. To investigate the mechanisms underlying arenavirus nAb evasion we engineered several arenavirus envelope-chimeric viruses and glycan-deficient variants thereof. We performed neutralization tests with sera from experimentally infected mice and from LASV-convalescent human patients. NAb response kinetics in mice correlated inversely with the N-linked glycan density in the arenavirus envelope protein's globular head. Additionally and most intriguingly, infection with fully glycosylated viruses elicited antibodies, which neutralized predominantly their glycan-deficient variants, both in mice and humans. Binding studies with monoclonal antibodies indicated that envelope glycans reduced nAb on-rate, occupancy and thereby counteracted virus neutralization. In infected mice, the envelope glycan shield promoted protracted viral infection by preventing its timely elimination by the ensuing antibody response. Thus, arenavirus envelope glycosylation impairs the protective efficacy rather than the induction of nAbs, and thereby prevents efficient antibody-mediated virus control. This immune evasion mechanism imposes limitations on antibody-based vaccination and convalescent serum therapy.
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http://dx.doi.org/10.1371/journal.ppat.1005276DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4654586PMC
November 2015
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