Deep immune profiling of chronic rhinosinusitis in allergic and non-allergic cohorts using mass cytometry

Chronic rhinosinusitis (CRS) is a persistent nasal and paranasal sinus mucosa inflammation comprising two phenotypes, namely CRS with nasal polyps (CRSwNP) and without (CRSsNP). CRSwNP can be associated with asthma and hypersensitivity to non-steroidal anti-inflammatory drug (NSAID) in a syndrome known as NSAID-exacerbated respiratory disease (N-ERD). Furthermore, CRS frequently intertwines with respiratory allergies. This study investigated levels of 33 different nasal and serum cytokines and phenotypic characteristics of peripheral blood mononuclear cells (PBMCs) within cohorts of CRS patients (n = 24), additionally examining the influence of comorbid respiratory allergies by mass cytometry. N-ERD patients showed heightened type 2 nasal cytokine levels. Mass cytometry revealed increased activated naive B cell levels in CRSwNP and N-ERD, while resting naive B cells were higher in CRSsNP. Th2a cell levels were significantly elevated in allergic subjects, but not in CRS groups. In conclusion, there are distinct immunological features in PBMCs of CRS phenotypes and allergy.

The adhesion G-protein-coupled receptor mayo/CG11318 controls midgut development in Drosophila

Adhesion G-protein-coupled receptors (aGPCRs) form a large family of cell surface molecules with versatile tasks in organ development. Many aGPCRs still await their functional and pharmacological deorphanization. Here, we characterized the orphan aGPCR CG11318/mayo of Drosophila melanogaster and found it expressed in specific regions of the gastrointestinal canal and anal plates, epithelial specializations that control ion homeostasis. Genetic removal of mayo results in tachycardia, which is caused by hyperkalemia of the larval hemolymph. The hyperkalemic effect can be mimicked by a raise in ambient potassium concentration, while normal potassium levels in mayoKO mutants can be restored by pharmacological inhibition of potassium channels. Intriguingly, hyperkalemia and tachycardia are caused non-cell autonomously through mayo-dependent control of enterocyte proliferation in the larval midgut, which is the primary function of this aGPCR. These findings characterize the ancestral aGPCR Mayo as a homeostatic regulator of gut development.

Cytokine-directed cellular cross-talk imprints synovial pathotypes in rheumatoid arthritis

INTRODUCTION

Structural reorganisation of the synovium with expansion of fibroblast-like synoviocytes (FLS) and influx of immune cells is a hallmark of rheumatoid arthritis (RA). Activated FLS are increasingly recognised as a critical component driving synovial tissue remodelling by interacting with immune cells resulting in distinct synovial pathotypes of RA.

METHODS

Automated high-content fluorescence microscopy of co-cultured cytokine-activated FLS and autologous peripheral CD4+ T cells from patients with RA was established to quantify cell-cell interactions. Phenotypic profiling of cytokine-treated FLS and co-cultured T cells was done by flow cytometry and RNA-Seq, which were integrated with publicly available transcriptomic data from patients with different histological synovial pathotypes. Computational prediction and knock-down experiments were performed in FLS to identify adhesion molecules for cell-cell interaction.

RESULTS

Cytokine stimulation, especially with TNF-α, led to enhanced FLS-T cell interaction resulting in cell-cell contact-dependent activation, proliferation and differentiation of T cells. Signatures of cytokine-activated FLS were significantly enriched in RA synovial tissues defined as lymphoid-rich or leucocyte-rich pathotypes, with the most prominent effects for TNF-α. FLS cytokine signatures correlated with the number of infiltrating CD4+ T cells in synovial tissue of patients with RA. Ligand-receptor pair interaction analysis identified ICAM1 on FLS as an important mediator in TNF-mediated FLS-T cell interaction. Both, ICAM1 and its receptors were overexpressed in TNF-treated FLS and co-cultured T cells. Knock-down of ICAM1 in FLS resulted in reduced TNF-mediated FLS-T cell interaction.

CONCLUSION

Our study highlights the role of cytokine-activated FLS in orchestrating inflammation-associated synovial pathotypes providing novel insights into disease mechanisms of RA.

Soft Reconstruction Kernels Improve HCC Imaging on a Photon-Counting Detector CT

RATIONALE AND OBJECTIVES

Hepatocellular carcinoma (HCC) is the only tumor entity that allows non-invasive diagnosis based on imaging without further histological proof. Therefore, excellent image quality is of utmost importance for HCC diagnosis. Novel photon-counting detector (PCD) CT improves image quality via noise reduction and higher spatial resolution, inherently providing spectral information. The aim of this study was to investigate these improvements for HCC imaging with triple-phase liver PCD-CT in a phantom and patient population study focusing on identification of the optimal reconstruction kernel.

MATERIALS AND METHODS

Phantom experiments were performed to analyze objective quality characteristics of the regular body and quantitative reconstruction kernels, each with four sharpness levels (36-40-44-48). For 24 patients with viable HCC lesions on PCD-CT, virtual monoenergetic images at 50 keV were reconstructed using these kernels. Quantitative image analysis included contrast-to-noise ratio (CNR) and edge sharpness. Three raters performed qualitative analyses evaluating noise, contrast, lesion conspicuity, and overall image quality.

RESULTS

In all contrast phases, the CNR was highest using the kernels with a sharpness level of 36 (all p < 0.05), with no significant influence on lesion sharpness. Softer reconstruction kernels were also rated better regarding noise and image quality (all p < 0.05). No significant differences were found in image contrast and lesion conspicuity. Comparing body and quantitative kernels with equal sharpness levels, there was no difference in image quality criteria, neither regarding in vitro nor in vivo analysis.

CONCLUSION

Soft reconstruction kernels yield the best overall quality for the evaluation of HCC in PCD-CT. As the image quality of quantitative kernels with potential for spectral post-processing is not restricted compared to regular body kernels, they should be preferred.

Individual and interactive effects of warming and nitrogen supply on CO2 fluxes and carbon allocation in subarctic grassland

Climate warming has been suggested to impact high latitude grasslands severely, potentially causing considerable carbon (C) losses from soil. Warming can also stimulate nitrogen (N) turnover, but it is largely unclear whether and how altered N availability impacts belowground C dynamics. Even less is known about the individual and interactive effects of warming and N availability on the fate of recently photosynthesized C in soil. On a 10-year geothermal warming gradient in Iceland, we studied the effects of soil warming and N addition on CO2 fluxes and the fate of recently photosynthesized C through CO2 flux measurements and a 13 CO2 pulse-labeling experiment. Under warming, ecosystem respiration exceeded maximum gross primary productivity, causing increased net CO2 emissions. N addition treatments revealed that, surprisingly, the plants in the warmed soil were N limited, which constrained primary productivity and decreased recently assimilated C in shoots and roots. In soil, microbes were increasingly C limited under warming and increased microbial uptake of recent C. Soil respiration was increased by warming and was fueled by increased belowground inputs and turnover of recently photosynthesized C. Our findings suggest that a decade of warming seemed to have induced a N limitation in plants and a C limitation by soil microbes. This caused a decrease in net ecosystem CO2 uptake and accelerated the respiratory release of photosynthesized C, which decreased the C sequestration potential of the grassland. Our study highlights the importance of belowground C allocation and C-N interactions in the C dynamics of subarctic ecosystems in a warmer world.

Basis for high-affinity ethylene binding by the ethylene receptor ETR1 of Arabidopsis

The gaseous hormone ethylene is perceived in plants by membrane-bound receptors, the best studied of these being ETR1 from Arabidopsis. Ethylene receptors can mediate a response to ethylene concentrations at less than one part per billion; however, the mechanistic basis for such high-affinity ligand binding has remained elusive. Here we identify an Asp residue within the ETR1 transmembrane domain that plays a critical role in ethylene binding. Site-directed mutation of the Asp to Asn results in a functional receptor that has a reduced affinity for ethylene, but still mediates ethylene responses in planta. The Asp residue is highly conserved among ethylene receptor-like proteins in plants and bacteria, but Asn variants exist, pointing to the physiological relevance of modulating ethylene-binding kinetics. Our results also support a bifunctional role for the Asp residue in forming a polar bridge to a conserved Lys residue in the receptor to mediate changes in signaling output. We propose a new structural model for the mechanism of ethylene binding and signal transduction, one with similarities to that found in a mammalian olfactory receptor.

Using mass cytometry for the analysis of samples of the human airways

Mass cytometry (MC) is a powerful method for mapping complex cellular systems at single-cell levels, based on the detection of cellular proteins. Numerous studies have been performed using human blood, but there is a lack of protocols describing the processing and labeling of bronchoalveolar lavage fluid (BALF) and nasal polyps (NP) for acquisition by MC. These specimens are essential in the investigation of immune cell characteristics in airway diseases such as asthma and chronic rhinosinusitis with NP (CRSwNP). Here we optimized a workflow for processing, labeling, and acquisition of BALF and NP cells by MC. Among three methods tested for NP digestion, combined enzymatic/mechanical processing yielded maximum cell recovery, viability and labeling patterns compared to the other methods. Treatment with DNAse improved sample acquisition by MC. In a final step, we performed a comparison of blood, BALF and NP cell composition using a 31-marker MC antibody panel, revealing expected differences between the different tissue but also heterogeneity among the BALF and NP samples. We here introduce an optimized workflow for the MC analysis of human NP and BALF, which enables comparative analysis of different samples in larger cohorts. A deeper understanding of immune cell characteristics in these samples may guide future researchers and clinicians to a better disease management.

A multicentre, randomised, double-blind, phase II study to evaluate the tolerability of an induction dose escalation of everolimus in patients with metastatic breast cancer (DESIREE)

BACKGROUND

Stomatitis is one of the main reasons to discontinue everolimus in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC). To decrease stomatitis and subsequently early treatment discontinuations or dose reductions, the DESIREE trial investigated the use of a stepwise dose-escalation schedule of everolimus (EVE esc).

PATIENTS AND METHODS

DESIREE is a phase II, multicentre, randomised, double-blind, placebo-controlled trial in patients with HR+/HER2- mBC and progression/relapse after nonsteroidal aromatase inhibitor treatment. Patients were randomised to EVE esc (2.5 mg/day, week 1; 5 mg/day, week 2; 7.5 mg/day, week 3; 10 mg/day, weeks 4-24) or everolimus 10 mg/day (EVE 10mg) for 24 weeks plus exemestane. The primary endpoint was the incidence of stomatitis episodes grade ≥2 within 12 weeks of treatment. The secondary endpoints included toxicity, relative total dose intensity (RTDI) and quality of life (QoL).

RESULTS

A total of 160 patients were randomised and 156 started treatment (EVE esc: 80; EVE 10mg: 76). The median age of patients was 64 years (range 33-85), 56.3% patients in the EVE esc arm versus 42.1% in the EVE 10mg arm had liver metastasis (P = 0.081) and 62.5% versus 51.3% received over one metastatic therapy line (P = 0.196). Within 12 weeks, the incidence of stomatitis episodes grade ≥2 was significantly lower in the EVE esc arm compared with the EVE 10mg arm (28.8% versus 46.1%; odds ratio 0.47, 95% confidence interval 0.24-0.92; P = 0.026). Toxicity was in line with the known safety profile without new safety concerns. The median RTDI was 91.1% in the EVE esc arm versus 80.0% in the EVE 10mg arm (P = 0.329). Discontinuation rate in the first 3 weeks was 6.3% versus 15.8%, respectively (P = 0.073). QoL was comparable between the two treatment arms.

CONCLUSIONS

A dose-escalation schema of everolimus over 3 weeks can be successfully used to reduce the incidence of high-grade stomatitis in the first 12 weeks of treatment in patients with HR+/HER2- mBC.

TRIAL REGISTRATION

ClinicalTrials.govNCT02387099; https://clinicaltrials.gov/ct2/show/NCT02387099.

Photon-counting detector CT improves quality of arterial phase abdominal scans: A head-to-head comparison with energy-integrating CT

PURPOSE

Photon-counting detector (PCD)-CT is expected to have a substantial impact on oncologic abdominal imaging. We compared subjective and objective image quality between PCD-CT and conventional energy-integrating detector (EID-)CT arterial phase abdominal scans.

METHODS

This study included 84 patients undergoing both types of abdominal CT. EID-CT scans were acquired with a tube voltage of 100 kVp. With PCD-CT, acquired with 120-kVp, we reconstructed polychromatic T3D images and virtual monoenergetic images (VMIs) in 10-keV intervals from 40 to 90 keV. Quantitative image analysis included noise and contrast-to-noise ratio (CNR) of hepatic vessels, kidney cortex, and hypervascular liver lesions to liver parenchyma. Three raters used a 5-point Likert scale for qualitative image analysis of image noise and contrast, lesion conspicuity, and overall image quality. Radiation dose exposure (CT dose index) was compared between the two CT types.

RESULTS

Mean CT dose index and effective dose were respectively 18 % and 26 % lower with PCD-CT versus EID-CT. Compared with EID-CT, CNRs of kidney cortex and vessel to liver parenchyma were significantly higher in PCD-CT VMIs at energies ≤ 60 keV and in polychromatic T3D images (p < 0.004). Overall image quality of PCD-CT VMIs at 50 and 60 keV was rated as significantly better (p < 0.01) than the EID-CT images (inter-reader agreement alpha = 0.80). Lesion conspicuity was significantly better in low-keV VMIs (p < 0.03) and worse in > 70-keV VMIs.

CONCLUSIONS

With low-keV VMI, PCD-CT yields significantly improved objective and subjective quality of arterial phase oncological imaging compared with EID-CT. This advantage may translate into higher diagnostic confidence and lower radiation dose protocols.

Spectroscopic and QM/MM studies of the Cu(I) binding site of the plant ethylene receptor ETR1

Herein, we present, to our knowledge, the first spectroscopic characterization of the Cu(I) active site of the plant ethylene receptor ETR1. The x-ray absorption (XAS) and extended x-ray absorption fine structure (EXAFS) spectroscopies presented here establish that ETR1 has a low-coordinate Cu(I) site. The EXAFS resolves a mixed first coordination sphere of N/O and S scatterers at distances consistent with potential histidine and cysteine residues. This finding agrees with the coordination of residues C65 and H69 to the Cu(I) site, which are critical for ethylene activity and well conserved. Furthermore, the Cu K-edge XAS and EXAFS of ETR1 exhibit spectroscopic changes upon addition of ethylene that are attributed to modifications in the Cu(I) coordination environment, suggestive of ethylene binding. Results from umbrella sampling simulations of the proposed ethylene binding helix of ETR1 at a mixed quantum mechanics/molecular mechanics level agree with the EXAFS fit distance changes upon ethylene binding, particularly in the increase of the distance between H69 and Cu(I), and yield binding energetics comparable with experimental dissociation constants. The observed changes in the copper coordination environment might be the triggering signal for the transmission of the ethylene response.

High RIG-I and EFTUD2 expression predicts poor survival in endometrial cancer

PURPOSE

Endometrial cancer is the most common gynecological malignancy. The helicase RIG-I, a part of the innate immune system, and EFTUD2, a splicing factor which can upregulate RIG-I expression, are shown to influence tumor growth and disease progression in several malignancies. For endometrial cancer, an immunogenic cancer, data about RIG-I and EFTUD2 are still missing. The aim of this study was to examine the expression of RIG-I and EFTUD2 in endometrial cancer.

METHODS

225 specimen of endometrial cancer were immunohistochemically stained for RIG-I and EFTUD2. The results were correlated to clinicopathological data, overall survival (OS) and progression-free survival (PFS).

RESULTS

High RIG-I expression correlated with advanced tumor stages (FIGO: p = 0.027; pT: p = 0.010) and worse survival rates (OS: p = 0.009; PFS: p = 0.022). High EFTUD2 expression correlated to worse survival rates (OS: p = 0.026; PFS: p < 0.001) and was determined to be an independent marker for progression-free survival.

CONCLUSION

Our data suggest that the expression of RIG-I and EFTUD2 correlates with survival data, which makes both a possible therapeutic target in the future.

Study protocol of the FIRE-8 (AIO-KRK/YMO-0519) trial: a prospective, randomized, open-label, multicenter phase II trial investigating the efficacy of trifluridine/tipiracil plus panitumumab versus trifluridine/tipiracil plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer

Background

Initial systemic therapy for patients with metastatic colorectal cancer (mCRC) is usually based on two- or three-drug chemotherapy regimens with fluoropyrimidine (5-fluorouracil (5-FU) or capecitabine), oxaliplatin and/or irinotecan, combined with either anti-VEGF (bevacizumab) or, for RAS wild-type (WT) tumors, anti-EGFR antibodies (panitumumab or cetuximab). Recommendations for patients who are not eligible for intensive combination therapies are limited and include fluoropyrimidine plus bevacizumab or single agent anti-EGFR antibody treatment. The use of a monochemotherapy concept of trifluridine/ tipiracil in combination with monoclonal antibodies is not approved for first-line therapy, yet. Results from the phase II TASCO trial evaluating trifluridine/ tipiracil plus bevacicumab in first-line treatment of mCRC patients and from the phase I/II APOLLON trial investigating trifluridine/ tipiracil plus panitumumab in pre-treated mCRC patients suggest favourable activity and tolerability of these new therapeutic approaches.

Methods

FIRE-8 (NCT05007132) is a prospective, randomized, open-label, multicenter phase II study which aims to evaluate the efficacy of first-line treatment with trifluridine/tipiracil (35 mg/m² body surface area (BSA), orally twice daily on days 1–5 and 8–12, q28 days) plus either the anti-EGFR antibody panitumumab (6 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm A] or (as control arm) the anti-VEGF antibody bevacizumab (5 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm B] in RAS WT mCRC patients. The primary objective is to demonstrate an improved objective response rate (ORR) according to RECIST 1.1 from 30% (control arm) to 55% with panitumumab. With a power of 80% and a two-sided significance level of 0.05, 138 evaluable patients are needed. Given an estimated drop-out rate of 10%, 153 patients will be enrolled.

Discussion

To the best of our knowledge, this is the first phase II trial to evaluate the efficacy of trifluridine/tipiracil plus panitumumab in first-line treatment of RAS WT mCRC patients. The administration of anti-EGFR antibodies rather than anti-VEGF antibodies in combination with trifluridine/tipiracil may result in an increased initial efficacy.

Trial registration

EU Clinical Trials Register (EudraCT) 2019-004223-20. Registered October 22, 2019, ClinicalTrials.govNCT05007132. Registered on August 12, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09892-8.

OP0079 SYNOVIAL FIBROBLASTS – T CELL INTERACTIONS ARE MAJOR DRIVERS OF INFLAMMATION: A CLOSER LOOK INTO THE JOINT

Background

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, which is characterized by synovial inflammation resulting in bone and cartilage destruction. Crosstalk between activated fibroblast-like synoviocytes (FLS) and immune cells, such as CD4+ T cells, within the synovium might amplify synovial inflammation and joint destruction.

Objectives

To define the interaction profile of activated FLS and CD4+ T cells within an inflammatory setting and to elucidate its consequence on synovial inflammation.

Methods

To screen for factors that activate FLS in RA, isolated FLS were treated with different inflammatory cytokines and transcriptomic changes were measured with RNA-seq. Fluorescence activated cell sorting (FACS) purified naïve CD4+ T-cells from the same patients were co-cultured with the cytokine pre-treated FLS. Automated fluorescence microscopy and downstream bioinformatic image analysis allowed visualization and quantification of cell-cell interactions. After co-culture T-cells were isolated and T-cell activation, proliferation and differentiation was determined by flow cytometry.

Results

To model the in vivo situation, FLS were pre-stimulated with different pro- and anti-inflammatory cytokines. RNA-seq revealed cytokine specific activation patterns of FLS. Correspondingly, we observed distinct CD4+ T cells – FLS interaction profiles depending on the cytokine used for FLS activation. In line with distinct interaction profiles, specific patterns in CD4+ T cells activation, proliferation and differentiation of naïve T cells into CD62Lhigh CD45ROhigh memory T cells could be detected. Signatures of cytokine-stimulated FLS could be identified in transcriptomic data from synovial tissue samples.

Conclusion

Within this study, we describe how cytokine induced CD4+ T cells – FLS interactions impact on T-cell proliferation, activation and differentiation.

References

[1]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

[2]Smolen JS, Aletaha D, Barton A, Burmester GR, Emery P, Firestein GS, et al. Rheumatoid arthritis. Nat Rev Dis Primers. 2018;4:18001.

[3]Smolen JS, Aletaha D, McInnes IB. Rheumatoid arthritis. The Lancet. 2016;388(10055):2023-38.

[4]Bartok B, Firestein GS. Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis. Immunol Rev. 2010;233(1):233-55.

[5]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

Disclosure of Interests

None declared.

MO055: Multi-Class Segmentation of Kidney Tissues using Convolutional Neuronal Networks (CNNS)

BACKGROUND AND AIMS

Routine pathological diagnostics in kidneys are mainly based on semi-quantitative eyeballing. In own former studies, we showed predictive value of precise immune cell quantification in allografts using digital semi-automated techniques. We now aim to achieve fully automated segmentation workflow with CNNs.

METHOD

Standard routine stains (immuno/histochemistry, immunofluorescence) were digitized (20×) with Metafer, a commercial scanning/imaging platform. Diagnostically relevant anatomical compartments (cortex, medulla, glomeruli, tubuli [proximal/distal/collecting duct], glomerular/peritubular capillaries and nuclei) were manually annotated by use of immunomarkers to generate large data sets on human renal biopsies and nephrectomies. Data were used to train multi-class semantic segmentation CNNs with broad data augmentation to achieve a robustness against staining variances.

RESULTS

Using Jones-HE stains for multi-class segmentation, a cortex-medulla-extrarenal CNN revealed pixel based hit rates above 97.9%, detection of glomeruli had a pixel based hit rate above 99%, a multi-class CNN for tubules, tubular membranes and peritubular capillaries resulted in a hit rate of 91.5%, and nuclear-based cell detection shows pixel based hit rates above 98%. Identification of cell location in interstitium, tubuli, glomeruli, peritubular and glomerular capillaries reached very high hit rates: Glomerular endothelial cells actually result in 83% true positives, 13% false negatives and 4% false positives. Additionally, a tubulus classifier (proximal tubulus, distal tubulus, collecting duct and atrophic tubulus) with an accuracy &gt;90% was developed.

CONCLUSION

Automated structure segmentation by CNNs can complement and specify classical nephropathological diagnostics, especially for spatial risk marker evaluation in early transplant biopsies.

Diagnostic accuracy of wrist MRI in comparison to wrist arthroscopy regarding TFCC lesions in clinical practice

INTRODUCTION

The purpose of this study was to arthroscopically verify MRI diagnostic accuracy for triangular fibrocartilage complex (TFCC) lesions in a regular clinical environment.

METHODS

A total of 859 patients' data with both preoperative MRI of the wrist and additional wrist arthroscopy were retrospectively reviewed. Two board-certified hand surgeons and one orthopaedic surgeon executed wrist arthroscopy, whereas more than 100 radiologists examined the MRI of the wrist. The accordance of TFCC lesion classification using MRI in comparison to wrist arthroscopy and diagnostic precision of the former depending on technical details were evaluated.

RESULTS

Diagnostic accuracy of MRI for TFCC lesions is poor in comparison to wrist arthroscopy as the reference standard. Technical specifications for MRI of the wrist are heterogeneous among the radiologists. These parameters have not improved accuracy of TFCC evaluation at large.

CONCLUSION

The accuracy of MRI in a regular clinical environment still remains inferior to wrist arthroscopy for detection of TFCC lesions. Development of a standard MRI protocol may be implemented on a regular basis and application of the Palmer classification for TFCC lesion should be sought.

Metabolic conjugation reduces in vitro toxicity of the flavonoid nevadensin

The present study focuses on the association between metabolic capacity and toxicity of the natural occurring flavonoid nevadensin in vitro. Human colon (HT29), liver (HepG2) and bone marrow (KG1) carcinoma cells were used and strong cell line dependent differences in toxic effect strength were found. HepG2 and KG1 cells were more sensitive against nevadensin treatment in comparison to HT29 cells. High resolution mass spectrometry experiments showed that nevadensin is rapidly glucuronidated in HT29 cells, whereas KG1 cells do not metabolize nevadensin, thus glucuronidation was supposed to be a crucial metabolic pathway in vitro. To proof this suggestion, nevadensin glucuronides were isolated from pig liver microsomes und structurally elucidated via NMR spectroscopy. In HepG2 cells a cellular enrichment of nevadensin itself as well as nevadensin-7-O-glucuronide was determined by tandem mass spectrometry. A proteomic screening of uridine 5'-diphospho (UDP)-glucuronosyltransferase (UGT) in HT29 and HepG2 cells provided first hints that the isoforms UGT1A6 and UGT1A1 are responsible for nevadensin glucuronidation. Additionally, nevadensin was found to be a potent SULT inhibitor in HepG2 cells. In sum, the present study clearly illustrates the importance of obtaining detailed information about metabolic competence of cell lines which should be considered in the evaluation of toxic endpoints.

Mapping the helix arrangement of the reconstituted ETR1 ethylene receptor transmembrane domain by EPR spectroscopy

The plant ethylene receptor ETR1 is a key player in the perception of the phytohormone and subsequent downstream ethylene signal transmission, crucial for processes such as ripening, senescence and abscission. However, to date, there is sparse structural knowledge about the transmembrane sensor domain (TMD) of ETR1 that is responsible for the binding of the plant hormone and initiates the downstream signal transmission. Sequence information and ab initio modelling suggest that the TMD consists of three transmembrane helices. Here, we combined site-directed spin labelling with electron paramagnetic resonance spectroscopy and obtained distance restraints for liposome-reconstituted ETR1_TMD on the orientation and arrangement of the transmembrane helices. We used these data to scrutinize different computational structure predictions of the TMD.

Prognostic relevance of the HER2 status of circulating tumor cells in metastatic breast cancer patients screened for participation in the DETECT study program

BACKGROUND

Circulating tumor cells (CTCs) have been reported to predict clinical outcome in metastatic breast cancer (MBC). Biology of CTCs may differ from that of the primary tumor and HER2-positive CTCs are found in some patients with HER2-negative tumors.

PATIENTS AND METHODS

Patients with HER2-negative MBC were screened for participation in DETECT III and IV trials before the initiation of a new line of therapy. Blood samples were analyzed using CELLSEARCH. CTCs were labeled with an anti-HER2 antibody and classified according to staining intensity (negative, weak, moderate, or strong staining).

RESULTS

Screening blood samples were analyzed in 1933 patients with HER2-negative MBC. As many as 1217 out of the 1933 screened patients (63.0%) had ≥1 CTC per 7.5 ml blood; ≥5 CTCs were detected in 735 patients (38.0%; range 1-35 078 CTCs, median 8 CTCs). HER2 status of CTCs was assessed in 1159 CTC-positive patients; ≥1 CTC with strong HER2 staining was found in 174 (15.0%) patients. The proportion of CTCs with strong HER2 staining among all CTCs of an individual patient ranged between 0.06% and 100% (mean 15.8%). Patients with estrogen receptor (ER)- and progesterone receptor (PR)-positive tumors were more likely to harbor ≥1 CTC with strong HER2 staining. CTC status was significantly associated with overall survival (OS). Detection of ≥1 CTC with strong HER2 staining was associated with shorter OS [9.7 (7.1-12.3) versus 16.5 (14.9-18.1) months in patients with CTCs with negative-to-moderate HER2 staining only, P = 0.013]. In multivariate analysis, age, ER status, PR status, Eastern Cooperative Oncology Group performance status, therapy line, and CTC status independently predicted OS.

CONCLUSION

CTC detection in patients with HER2-negative disease is a strong prognostic factor. Presence of ≥1 CTC with strong HER2 staining was associated with shorter OS, supporting a biological role of HER2 expression on CTCs.

Insights into Ergochromes of the Plant Pathogen Claviceps purpurea

Claviceps purpurea is an ergot fungus known for its neurotropic alkaloids, which have been identified as the main cause of ergotism, a livestock and human disease triggered by ergot consumption. Tetrahydroxanthone dimers, the so-called ergopigments, presumably also contribute to this toxic effect. Overexpression of the cluster-specific transcription factor responsible for the formation of these pigments in C. purpurea led to the isolation of three new metabolites (8-10). The new pigments were characterized utilizing HRMS, NMR techniques, and CD spectroscopy and shown to be xanthone dimers. Secalonic acid A and its 2,4'- and 4,4'-linked isomers were also isolated, and their absolute configuration was investigated. The contribution of secalonic acid A, its isomers, and new metabolites to the toxicity of C. purpurea was investigated in HepG2 and CCF-STTG1 cells. Along with cytotoxic properties, secalonic acid A was found to inhibit topoisomerase I and II activity.

Characterization of Oligomeric Proanthocyanidin-Enriched Fractions from Aronia melanocarpa (Michx.) Elliott via High-Resolution Mass Spectrometry and Investigations on Their Inhibitory Potential on Human Topoisomerases

Aronia melanocarpa (MICHX.) ELLIOTT, which belongs to the Rosaceae family, has increasingly come into focus of research due to the high content of polyphenols. In addition to antioxidative properties, further health-promoting effects of these polyphenols are still of interest. Especially, the proanthocyanidins offer thereby huge opportunities due to their high structural heterogeneity. Therefore, the present study focuses on the topoisomerase inhibiting effects of oligomeric proanthocyanidins (PACs), which are potentially depended on their degree of polymerization. The investigated PACs isolated from Aronia berries were characterized by chromatographic techniques and liquid chromatography-high-resolution mass spectrometry. Four PAC enriched fractions were obtained from Aronia pomace containing 47 PACs with a degree of polymerization from three to six. Due to the low yield of hexamers, the potential inhibiting effects against human topoisomerase were investigated for the trimer to pentamer fractions. The relaxation and decatenation assays were performed to examine the inhibiting effect on topoisomerases under cell-free conditions. Moreover, rapid isolation of topoisomerase cleavage complexes in human colon carcinoma HT29 cells was performed to evaluate the effect on topoisomerases in a cell-based system. The fractions demonstrated inhibitory potential on topoisomerases I and II. In sum, an increasing effect strength depending on the degree of polymerization was shown.

Granzyme A and CD160 expression delineates ILC1 with graded functions in the mouse liver

Type 1 innate lymphoid cells (ILC1) are tissue‐resident lymphocytes that provide early protection against bacterial and viral infections. Discrete transcriptional states of ILC1 have been identified in homeostatic and pathological contexts. However, whether these states delineate ILC1 with different functional properties is not completely understood. Here, we show that liver ILC1 are heterogeneous for the expression of distinct effector molecules and surface receptors, including granzyme A (GzmA) and CD160, in mice. ILC1 expressing high levels of GzmA are enriched in the liver of adult mice, and represent the main hepatic ILC1 population at birth. However, the heterogeneity of GzmA and CD160 expression in hepatic ILC1 begins perinatally and increases with age. GzmA⁺ ILC1 differ from NK cells for the limited homeostatic requirements of JAK/STAT signals and the transcription factor Nfil3. Moreover, by employing Rorc(γt)‐fate map (fm) reporter mice, we established that ILC3‐ILC1 plasticity contributes to delineate the heterogeneity of liver ILC1, with RORγt‐fm⁺ cells skewed toward a GzmA^–CD160⁺ phenotype. Finally, we showed that ILC1 defined by the expression of GzmA and CD160 are characterized by graded cytotoxic potential and ability to produce IFN‐γ. In conclusion, our findings help deconvoluting ILC1 heterogeneity and provide evidence for functional diversification of liver ILC1.

Warming and elevated CO2 intensify drought and recovery responses of grassland carbon allocation to soil respiration

Photosynthesis and soil respiration represent the two largest fluxes of CO₂ in terrestrial ecosystems and are tightly linked through belowground carbon (C) allocation. Drought has been suggested to impact the allocation of recently assimilated C to soil respiration; however, it is largely unknown how drought effects are altered by a future warmer climate under elevated atmospheric CO₂ (eT_eCO₂ ). In a multifactor experiment on managed C3 grassland, we studied the individual and interactive effects of drought and eT_eCO₂ (drought, eT_eCO₂ , drought × eT_eCO₂ ) on ecosystem C dynamics. We performed two in situ ¹³ CO₂ pulse-labeling campaigns to trace the fate of recent C during peak drought and recovery. eT_eCO₂ increased soil respiration and the fraction of recently assimilated C in soil respiration. During drought, plant C uptake was reduced by c. 50% in both ambient and eT_eCO₂ conditions. Soil respiration and the amount and proportion of ¹³ C respired from soil were reduced (by 32%, 70% and 30%, respectively), the effect being more pronounced under eT_eCO₂ (50%, 84%, 70%). Under drought, the diel coupling of photosynthesis and SR persisted only in the eT_eCO₂ scenario, likely caused by dynamic shifts in the use of freshly assimilated C between storage and respiration. Drought did not affect the fraction of recent C remaining in plant biomass under ambient and eT_eCO₂ , but reduced the small fraction remaining in soil under eT_eCO₂ . After rewetting, C uptake and the proportion of recent C in soil respiration recovered more rapidly under eT_eCO₂ compared to ambient conditions. Overall, our findings suggest that in a warmer climate under elevated CO₂ drought effects on the fate of recent C will be amplified and the coupling of photosynthesis and soil respiration will be sustained. To predict the future dynamics of terrestrial C cycling, such interactive effects of multiple global change factors should be considered.

Deficiency of Cathelicidin-related Antimicrobial Peptide Promotes Skin Papillomatosis in Mus musculus Papillomavirus 1-infected Mice

Cathelicidins have been reported to inhibit human papillomavirus infection in vitro; however, nothing is known about their activity in vivo. In this study, experimental skin infection with Mus musculus papillomavirus 1 resulted in robust development of cutaneous papillomas in cyclosporine A-treated C57BL/6J mice deficient for the murine cathelicidin-related antimicrobial peptide (CRAMP), in contrast to wild-type controls. Analysis of the underlying mechanisms revealed moderate disruption of virion integrity and lack of interference with viral entry and intracellular trafficking by a synthetic CRAMP peptide. Differences in the immune response to Mus musculus papillomavirus 1 infection were observed between CRAMP-deficient and wild-type mice. These included a stronger reduction in CD4+ and CD8+ T-cell numbers in infected skin, and lack of Mus musculus papillomavirus 1-specific neutralizing antibodies in response to cyclosporine A in the absence of endogenous CRAMP. CRAMP has modest direct anti-papillomaviral effects in vitro, but exerts protective functions against Mus musculus papillomavirus 1 skin infection and disease development in vivo, primarily by modulation of cellular and humoral immunity.

α-Asarone, β-asarone, and γ-asarone: Current status of toxicological evaluation

Asarone isomers are naturally occurring in Acorus calamus Linné, Guatteria gaumeri Greenman, and Aniba hostmanniana Nees. These secondary plant metabolites belong to the class of phenylpropenes (phenylpropanoids or alkenylbenzenes). They are further chemically classified into the propenylic trans- and cis-isomers α-asarone and β-asarone and the allylic γ-asarone. Flavoring, as well as potentially pharmacologically useful properties, enables the application of asarone isomers in fragrances, food, and traditional phytomedicine not only since their isolation in the 1950s. However, efficacy and safety in humans are still not known. Preclinical evidence has not been systematically studied, and several pharmacological effects have been reported for extracts of Acorus calamus and propenylic asarone isomers. Toxicological data are rare and not critically evaluated altogether in the 21st century yet. Therefore, within this review, available toxicological data of asarone isomers were assessed in detail. This assessment revealed that cardiotoxicity, hepatotoxicity, reproductive toxicity, and mutagenicity as well as carcinogenicity were described for propenylic asarone isomers with varying levels of reliability. The toxicodynamic profile of γ-asarone is unknown except for mutagenicity. Based on the estimated daily exposure and reported adverse effects, officials restricted or published recommendations for the use of β-asarone and preparations of Acorus calamus. In contrast, α-asarone and γ-asarone were not directly addressed due to a limited data situation.

NCOR1 Orchestrates Transcriptional Landscapes and Effector Functions of CD4+ T Cells

The differentiation of naïve CD4+ T cells into T helper (Th) subsets is key for a functional immune response and has to be tightly controlled by transcriptional and epigenetic processes. However, the function of cofactors that connect gene-specific transcription factors with repressive chromatin-modifying enzymes in Th cells is yet unknown. Here we demonstrate an essential role for nuclear receptor corepressor 1 (NCOR1) in regulating naïve CD4+ T cell and Th1/Th17 effector transcriptomes. Moreover, NCOR1 binds to a conserved cis-regulatory element within the Ifng locus and controls the extent of IFNγ expression in Th1 cells. Further, NCOR1 controls the survival of activated CD4+ T cells and Th1 cells in vitro, while Th17 cell survival was not affected in the absence of NCOR1. In vivo, effector functions were compromised since adoptive transfer of NCOR1-deficient CD4+ T cells resulted in attenuated colitis due to lower frequencies of IFNγ+ and IFNγ+IL-17A+ Th cells and overall reduced CD4+ T cell numbers. Collectively, our data demonstrate that the coregulator NCOR1 shapes transcriptional landscapes in CD4+ T cells and controls Th1/Th17 effector functions.

The interplay between cognitive control and emotional processing in children and adolescents

This study examined interactions between cognitive control and emotional processing throughout adolescent development. In particular, we investigated whether age differences in response inhibition and initiation were influenced by an emotional expression of faces and whether the effects differed from processing of nonemotional features of faces. Therefore, we applied two versions of a Go/No-go task, an emotional task requiring responding or withholding responding to happy and angry faces, and a gender task including decisions to female and male faces in a large sample (N = 187, age range = 9-18 years). Considering theoretical assumptions of dual-system models that mid-adolescents are more susceptible to the processing of emotional contents, we expected more inefficient response inhibition on happy and angry trials than on neutral trials. We also expected that these effects would be specific to emotional contents. Results indicated that both response inhibition and initiation showed linear improvements with increasing age. Response inhibition was hampered in the presence of happy and angry faces, especially in mid-adolescents and late adolescents. In contrast, response initiation was highly facilitated to happy faces, indicating a happy effect, leading to more accurate responding in all age groups and to faster responding especially in late adolescents. Children, in contrast to late adolescents, were more accurate in response inhibition and initiation when the gender was task relevant. Results are in line with dual-system models, assuming a higher sensitivity to emotional features from mid-adolescents onward but not to other features such as gender.

Histone deacetylase 1 (HDAC1): A key player of T cell-mediated arthritis

Rheumatoid Arthritis (RA) represents a chronic T cell-mediated inflammatory autoimmune disease. Studies have shown that epigenetic mechanisms contribute to the pathogenesis of RA. Histone deacetylases (HDACs) represent one important group of epigenetic regulators. However, the role of individual HDAC members for the pathogenesis of arthritis is still unknown. In this study we demonstrate that mice with a T cell-specific deletion of HDAC1 (HDAC1-cKO) are resistant to the development of Collagen-induced arthritis (CIA), whereas the antibody response to collagen type II was undisturbed, indicating an unaltered T cell-mediated B cell activation. The inflammatory cytokines IL-17 and IL-6 were significantly decreased in sera of HDAC1-cKO mice. IL-6 treated HDAC1-deficient CD4⁺ T cells showed an impaired upregulation of CCR6. Selective inhibition of class I HDACs with the HDAC inhibitor MS-275 under Th17-skewing conditions inhibited the upregulation of chemokine receptor 6 (CCR6) in mouse and human CD4⁺ T cells. Accordingly, analysis of human RNA-sequencing (RNA-seq) data and histological analysis of synovial tissue samples from human RA patients revealed the existence of CD4⁺CCR6⁺ cells with enhanced HDAC1 expression. Our data indicate a key role for HDAC1 for the pathogenesis of CIA and suggest that HDAC1 and other class I HDACs might be promising targets of selective HDAC inhibitors (HDACi) for the treatment of RA.