Definitive and Salvage Radiotherapy Compared to Other Modalities for Laryngeal Carcinoma in Situ

PURPOSE/OBJECTIVE(S)

We sought to analyze survival endpoints for laryngeal carcinoma in situ (CIS) undergoing definitive radiotherapy (RT) compared to other modalities.

MATERIALS/METHODS

Usingour prospectively maintained head and neck cancer database, we identified laryngeal CIS patients treated between 6/2001 and 12/2021. We excluded low-grade dysplasia, CIS with any synchronous invasive squamous cell carcinoma (SCC) within 3 months of the initial CIS biopsy and cases with inadequate follow up. Patients were offered either definitive RT, CO2/KTP laser ablation, photodynamic therapy (PDT) or any sort of therapeutic excision. After first line treatment, follow-up includes visits every 3-6 months with laryngoscopy and biopsies as appropriate. For recurrent CIS beyond 6 months of first line treatment, we reported salvage therapies received and long-term outcomes were reported. Using Kaplan-Meier curves and log-rank test we investigated recurrence free (RFS), progression to invasive SCC free (IFS) and overall (OS) survival across treatment groups. Patients managed with salvage RT were compared to first line RT recipients.

RESULTS

Atotal of 85 CIS cases were included: median age 65 years (IQR: 55-74), 73 males (85%) and 70 white (82.4%). 86% had a history of smoking with median pack year of 38 (IQR: 20-55) and 66% had a history of alcohol use. CIS was glottic in most of the cases (90.6%: 66% unilateral, 21% bilateral & 13% involved commissure); with only 9.4% in the supraglottic region. RT was used in 49.4% (n = 42) after biopsy (55%) or surgery (45%) with median dose of 63 Gy/28 fractions, mainly by 3D conformal RT (76%). The remaining 50.6% (n = 43) got therapeutic excision alone (commonly microflap excision) (46.5%), CO2/KTP laser (32.6%) or PDT (20.9%). Demographics and clinicopathological details were non-different between RT and non-RT patients except for Charlson comorbidity index: median 2 (IQR 1-3) in non-RT vs 1 (IQR 0-2) in 1ry RT; p = 0.007. After a median follow-up of 4.8 years (IQR 3.5), 51.8% had recurrent disease, 21.2% progressed to invasive SCC and 9.4% had laryngectomies mainly for invasive SCC after RT. First line RT had improved 2-(83% vs 39%) and 5-(74% vs 22%) year RFS vs non-RT therapies (p<0.001). Nevertheless, 2- and 5-year IFS (89% vs 98% and 80% vs 79%) and OS (92% vs 93% and 81% vs 77%) were non-significant among both (p>0.05 for all). Among non-RT cases with CIS recurrences, 12/35 (34%) had salvage RT. Following RT, salvage RT patients had similar 2- and 5-year RFS (81% vs 83% and 81% vs 74%) and IFS (81% vs 89% and 81% vs 80%) compared to first line RT (p>0.05 for all). All cases with CIS recurrences were salvaged successfully with 100% living with no CIS at latest follow-up.

CONCLUSION

Laryngeal CIS can be treated with a wide range of modalities including 1ry RT which has better recurrence free survival. Nevertheless, non-RT recurrent CIS can be salvaged successfully with many options including RT with equivalent long-term results.

Retinal Ependymoma: A Rare Extra-Axial Presentation

Introduction/Objective

Ependymomas are well-demarcated and slow-growing neuroepithelial neoplasms that comprise 3–9% of primary CNS tumors. The vast majority of ependymomas arise either intracranially, mostly in children, or in the spinal cord and are associated with ependymal lining. Histologic hallmarks are perivascular pseudorosettes, ependymal rosettes and alternating zones of nuclear crowding and nuclear free zones composed of coarse cell processes. In high grade ependymomas increased mitoses, necrosis and nuclear pleomorphism may be seen.

Methods

We present the case of a 63-year-old woman in with a past medical history of retinopathy of prematurity, glaucoma and right eye enucleation. She presented with a painful blind left eye refractory to medical treatment and subsequently underwent left eye enucleation.

Results

On histologic examination, an incidental retinal ependymoma was identified. The neoplastic cells were fusiform and had long coarsely fibrillar cell processes. Characteristic periodicity of nuclear crowding and scarcity was observed. In places, neoplastic cell processes extended radially to delicate and sometimes hyalinized blood vessels, forming so-called perivascular pseudorosettes. Definite ependymal rosettes were not recognized in the examined sections. Stigmata of chronicity were found, such as ischemic type necrosis, blood vessels with dystrophic calcifications and foci of ossification replete with fibroadipose tissue in the marrow spaces.

The neoplastic cells labeled with antibodies against glial fibrillary acidic protein (GFAP), thus confirming glial lineage in the neoplastic cell. Additionally, there was scattered intracytoplasmic expression of epithelial membrane antigen (EMA) in a dot-like or circular pattern. The latter is well described in ependymomas and often used to support the diagnosis.

Conclusion

Ependymomas rarely occur at extracranial sites, such as the chest, abdomen and pelvis. We are presenting the fourth case of retinal ependymoma reported in literature. The tumor had classical immunomorphologic findings.

0255 Comparing Performance, Fatigue and Sleepiness Between Short-Haul And Ultra Long-Haul Commercial Airline Operations

Introduction

Safety performance indicators (SPIs) are used in aviation to determine if a trip that is non-compliant with federal regulations is safe to fly. Exemptions to regulations can be granted if a safety case demonstrates that the SPIs for an alternative means of compliance (AMOC; i.e., a trip outside regulations) are non-inferior to SPIs for a safety standard operation (SSO; i.e. a trip compliant with regulations). Through this process, it has previously been suggested that ultra-long-range flights are non-inferior to long-range flights due to increased sleep opportunity. We determined whether SPIs for non-compliant ultra-long-range (ULR) trips are non-inferior to those for compliant short-haul (SH) trips.

Methods

Performance, fatigue, and sleepiness were assessed at the top of descent (TOD) of flight segments using the Psychomotor Vigilance Task (PVT), Samn-Perelli (SP) fatigue scale, and Karolinska Sleepiness Scale (KSS), respectively. Data were analyzed using non-inferiority testing. Two different ULR trips with different TOD times (ULR trip 1: n=81; ULR trip 2: n=22) were compared to two types of SH trips, including one trip that contained one or more all-night flights (SH trip 1: n=48) and one trip with zero all-night flights (SH trip 2: n=47).

Results

Non-inferiority was found for the SPIs at most comparison points. For example, comparing the SPIs for ULR trip 2 and SH trip 1 at final TOD, non-inferiority was found for all SPIs. In contrast, comparing the SPIs for ULR trip 1 and SH trip 1 at final TOD, non-inferiority was found for SP and KSS, while non-inferiority for PVT was only suggested.

Conclusion

The findings suggest that the AMOC trips are as safe as or safer than the compliant SH trips. This raises questions regarding the structure of SH trips and how differences in the structures play a role in performance, fatigue and sleepiness.

Support

United Airlines

0244 Examining Pilot Safety Performance Indicators at Critical Phases of Flight Across Multiple Flight Legs During Commercial Airline Trips

Introduction

Prior simulation and operational studies have started to address whether the number of consecutive flight segments negatively affects cognitive performance, fatigue, and sleepiness, without reaching a clear consensus. This study expands this literature by determining whether there are significant changes in cognitive performance, fatigue, and sleepiness at critical phases of flight across multiple flight segments, while accounting for the number of segments, flight direction, trip day, and time-of-day.

Methods

Fifty commercial airline pilots were studied. Each pilot flew two separate short-haul trips, each ranging from 1–4 days and 1–10 flight segments. Cognitive performance, fatigue, and sleepiness were assessed at top-of-climb (TOC) and top-of-descent (TOD) of each flight segment and each trip day. Cognitive performance, fatigue, and sleepiness were assessed using Psychomotor Vigilance Task (PVT) speed, Samn-Perelli (SP) ratings, and Karolinska Sleepiness Scale (KSS) ratings, respectively. Data were analyzed using Wilcoxon t-tests and verified using ANOVAs.

Results

Mean PVT speed (Cohen’s d =0.57), SP ratings (Cohen’s d = 0.73), and KSS ratings (Cohen’s d = 0.63) were significantly worse at TOD than TOC (p &lt; 0.001); and, significantly varied across flight segments (p&lt;0.001). Cognitive performance, fatigue, and sleepiness were consistently and significantly degraded around the fifth flight segment, improved around the sixth to eighth flights segments, and were subsequently degraded around the eighth to tenth flight segments.

Conclusion

The results indicate that cognitive performance, fatigue, and sleepiness vary across flight segments, trip day, and phase of flight. Results suggest that these safety performance indices degrade after five segments, and further degrade after eight flight segments. The results presented could be used to inform future airline scheduling and regulation.

Support

This work has been supported by United Airlines.

Lead, zinc, and copper redistributions in soils along a deposition gradient from emissions of a Pb-Ag smelter decommissioned 100 years ago

Sourcing and understanding the fate of anthropogenic metals in a historical contamination context is challenging. Here we combined elemental and isotopic (Pb, Zn, Cu) analyses with X-ray Absorption Spectroscopy (XAS) measurements (Zn) to trace the fate, in undisturbed soil profiles, of historical metal contamination emitted by a 167-year-old Pb-Ag smelter decommissioned 100 years ago located in the Calanques National Park (Marseilles, France). Lead isotopic measurements show that entire soil profiles were affected by 74 years of Pb emissions up to ~7 km from the smelter under the main NNW wind, and indicate particulate transfer down to 0.8 m at depth. This vertical mobility of anthropogenic Pb contrasts with previous studies where Pb was immobilized in surface horizons. The contribution of anthropogenic Pb to the total Pb concentration in soil was estimated at 95% in surface horizons, and 78% in the deepest horizons. Zinc isotopic signatures of past emissions that are enriched in light isotopes compared to the natural geological background (-0.70 ± 0.04‰ and -0.15 ± 0.02‰, respectively), were detected only in the surface horizons of the studied soils. Using XAS analyses, we showed that anthropogenic Zn was transformed and immobilized in surface horizons as Zn-Layered Double Hydroxide, thus favoring the enrichment in heavy isotopes in these surface horizons. No clear evidence of copper contamination by the smelter was found and Cu isotopes point to a bedrock origin and a natural distribution of Cu concentrations.

Evaluation of historical atmospheric pollution in an industrial area by dendrochemical approaches

We conducted a dendrochemical study in order to evaluate the exposure of territories and populations to different types of pollutants and to characterise the history of pollution in one of the most intensely industrialised areas of Europe: the industrial port zone of Fos, also heavily urbanised. To perform the study, two tree species have been selected, Pinus halepensis and Populus nigra, on a rural plot located roughly 20 km away from the industrial harbour, an urban plot located in the city of Fos-sur-Mer and an industrial plot. Our study indicated that poplar was a more relevant model for the dendrochemical studies, exhibiting a higher bioaccumulation capacity than pine except for Hg, Sb and Mn. Moreover, thanks to this work, we observed significant exposure of the trees in the urban and industrial areas to As, Cd, Co, Cu, Mo, Sb, Zn, Al, Ca, and Mg, highlighting the exposure of the territory and populations living in the vicinity of the industrial harbour. The temporal variability of the concentrations measured in the tree rings corresponds to the increasing industrialisation of the territory as well as to the evolution of the industrial processes. Thus, this project highlighted the exposure of the Gulf of Fos to atmospheric emissions (industrial, road and urban) of the industrial harbour as well as the changes over time. It also pointed out the relevance of using dendrochemistry to measure atmospheric exposure of metals and metalloids and its temporal variability.

The ProSeal Laryngeal Mask Airway in Prone Patients: A Retrospective Audit of 245 Patients

The use of the classic laryngeal mask airway (classic LMA) in the prone position is controversial, but the ProSeal laryngeal mask airway (ProSeal LMA) maybe more suitable as it forms a better seal and provides access to the stomach. In the following retrospective audit, we describe our experience with the insertion of, and maintenance of anaesthesia with, the ProSeal LMA in 245 healthy adults in the prone position by experienced users. The technique involved (1) the patient adopting the prone position with the head to the side and the table tilted laterally; (2) preoxygenation to end-tidal oxygen >90%; (3) induction of anaesthesia with midazolam/alfentanil/propofol; (4) facemask ventilation (5) a single attempt at digital insertion and if unsuccessful a single attempt at laryngoscope-guided, gum elastic bougie-guided insertion; (6) gastric tube insertion; (7) maintenance of anaesthesia with sevoflurane/O2/N2O; (8) volume controlled ventilation at 8-12 ml/kg; (9) emergence from anaesthesia in the supine position; and (10) removal of the ProSeal LMA when awake. Facemask ventilation was always successful. ProSeal LMA insertion was successful in all patients: 237 with digital insertion and eight with bougie-guided insertion. Ventilation was successful in all patients. Gastric tube insertion was successful in all patients. Correctable partial airway obstruction occurred in three patients, but there was no hypoxia, hypercapnoea, displacement, regurgitation, gastric insufflation or airway reflex activation. Our findings suggest that the insertion of and maintenance of anaesthesia with the ProSeal LMA is feasible in the prone position by experienced users.

Residual Protein Contamination of ProSeal™ Laryngeal Mask Airways after Two Washing Protocols

The risk of prion protein cross-infection has focussed attention on the potential hazards of protein contamination of re-usable medical devices. This study determined the frequency of protein contamination of ProSeal™ laryngeal mask airways (PLMA) after two cleaning procedures and tested the hypothesis that the combination of hand- and machine-washing removes protein contamination more effectively than hand-washing alone. After clinical use fifty-four PLMAs were randomly allocated to be washed by hand or by hand then machine. All PLMAs were then autoclaved at 134°C for 4 minutes. After processing, each PLMA was immersed in a 1.2% solution of erythrosin B and examined for uptake of stain. The site (outer surface, bowl and edges of the cuff, airway and drain tube, finger strap) and severity (nil/mild/moderate/severe) of staining was scored by a blinded observer. There were no differences in the site or severity of staining between the two cleaning procedures. Staining was detected on 89% of PLMAs that were hand-washed and 78% of PLMAs that were hand-, then machine-washed (P=0.27). When staining occurred, it was mild in 98%, moderate in 2% and was never severe. Staining was more frequent on the edge than at any other location (all comparisons: P≤0.01). The strap never had any staining. We conclude that residual contamination of PLMAs with protein deposits is common even when machine-washing is used to augment hand-washing before autoclaving. The infection risk associated with these deposits remains to be determined.

Gum Elastic Bougie-guided Insertion of the ProSeal™ Laryngeal Mask Airway

We tested the hypothesis that gum elastic-bougie-guided insertion of the ProSeal™ Laryngeal Mask Airway is more frequently successful than introducer tool guided insertion after failed digital insertion. One hundred anaesthetized patients (ASA 1-2, aged 18 to 80 years) were randomized for the second insertion attempt using either the gum elastic bougie-guided or introducer tool techniques. The bougie-guided technique involved priming the drain tube with the bougie, placing the bougie in the oesophagus using laryngoscope guidance, digital insertion along the palato-pharyngeal curve, and bougie removal. The introducer tool technique involved attaching the introducer tool, single-handed rotation along the palatopharyngeal curve, and introducer tool removal. Failed insertion was classified as (i) failed passage into the pharynx, (ii) malposition, or (iii) ineffective ventilation. Any blood staining was documented. Insertion was more frequently successful (50/50 vs 15/50, P=0.0002) and faster (35±17s vs 54±45s, mean±SD, P=0.006) with the bougie-guided technique. All failed insertions with the introducer tool technique were successful with the bougie-guided technique. The aetiology of failed insertion was similar for the digital and introducer tool techniques in 94% (33/35) of patients. There was no blood staining on the bougie, laryngoscope or introducer tool at removal, but blood staining was more common on the Proseal laryngeal mask airway with the introducer tool technique (9/50 vs 2/50, P=0.03). We conclude that the gum elastic bougie-guided insertion has a higher success rate and causes less trauma than the insertion tool insertion technique after failed digital insertion of the Proseal Laryngeal Mask Airway.

Positive Pressure versus Pressure Support Ventilation at Different Levels of PEEP Using the ProSeal™ Laryngeal Mask Airway

We compared positive pressure ventilation with pressure support ventilation at different levels of positive end expiratory pressure (PEEP) using the ProSeal laryngeal mask airway (PLMA). Forty-two anaesthetized adults (ASA 1-2, aged 19 to 63 years) underwent positive pressure ventilation and then pressure support ventilation each with PEEP set at 0, 5 and 10 cmH2O in random order. Pressure support ventilation was with the inspired tidal volume (VTInsp) set at 7 ml/kg and the respiratory rate adjusted to maintain the end-tidal CO2 (ETCO2) at 40 mmHg. Pressure support ventilation was with pressure support set at 5 cmH2O above PEEP and initiated when inspiration produced a 2 cmH2O reduction in airway pressure. Tidal volumes were similar during positive pressure and pressure support ventilation with PEEP, but were higher for the former without PEEP. Respiratory rate and peak inspiratory flow rate were higher during pressure support than positive pressure ventilation (all P<0.001). Peak airway pressure (Ppaw), mean airway pressure (Mpaw), peak expiratory flow rate, and expired airway resistance were lower during pressure support than positive pressure ventilation (all P<0.001). With PEEP set at 10 cmH2O, ETCO2 was lower for pressure support than positive pressure ventilation. During positive pressure ventilation, there was an increase in Ppaw, Mpaw and dynamic compliance (Cdyn) with increasing levels of PEEP (all P<0.01). During pressure support ventilation, there was an increase in inspired and expired tidal volume, Ppaw, peak inspiratory and expiratory flow rates and Cdyn, and a reduction in ETCO2, work of breathing, and expired airway resistance with increasing levels of PEEP (all P<0.01). There were no differences in SpO2, non-invasive mean arterial pressure, heart rate or leak fraction. We conclude that pressure support ventilation provides equally effective gas exchange as positive pressure ventilation during PLMA anaesthesia with or without PEEP at the tested settings. During pressure support, PEEP increases ventilation and reduces work on breathing without increasing leak fraction.

Differential regulation of transcription by the NURR1/NUR77 subfamily of nuclear transcription factors

NURR1 is an orphan member of the nuclear receptor superfamily of transcription factors that shares close sequence homology to the orphan nuclear receptor and immediate early gene product NUR77(NGF1 beta). The physiological role of NURR1 has not been established in mammalian cells. However, the observation that NURR1 and NUR77 interact with at least one common enhancer element (AAAAGGTCA), together with their partly overlapping but differential expression patterns in mammalian tissues, suggests that these proteins may have both shared and independent transcription regulatory functions. To identify potential target genes that may be regulated by NURR1, we analyzed its DNA binding properties to potential cis-acting enhancer elements. Using point mutagenesis of the AAAAGGTCA motif, we have identified three additional sequences that bind specifically to both NURR1 and NUR77, one of which serves as a functional enhancer element. Comparative analysis of the transcription regulatory properties of NURR1 and NUR77 indicates that the proteins can display opposing transregulatory activities that are influenced by the specific cis-acting sequences to which they bind. Our results indicate that the transcriptional responses of specific target genes to the NURR1/NUR77 subfamily may be differentially regulated by the relative cellular levels of NURR1 and NUR77 and influenced by the specific enhancer sequences that mediate their activity. Finally, we have identified several potential target genes of neuronal and neuroendocrine origin whose promoters contain this element.

Piscine mycobacteriosis - Involvement of bacterial species and reflection in pathology

INTRODUCTION

Piscine mycobacteriosis is a lethal disease with zoonotic potential, found worldwide in both fresh and marine fish. More than 20 strains of Mycobacterium spp. are known to persist in fish so far, but the pathogenicity is currently unknown for most of them. However, M. marinum is reported as one of the most pathogenic agents for fish and is involved in zoonotic cases. We examined 47 different cases from two zoological gardens, where fish tuberculosis was identified or previously suspected during the last ten years. We collected PCR and sequencing data, which were then compared to previously collected clinical data and pathology. The clinical signs caused by Mycobacterium spp. were similar in all the cases, except for cases infected by M. marinum, which lacked the presence of skin lesions. Lesions seen in histology caused by M. marinum tended to be more acute and severe compared lesions caused by other Mycobacterium spp. The majority of M. marinum cases have been reported within marine fish. In contrast to previous studies we detected this species to be the predominant bacteria present within freshwater fish. Interestingly, we detected M. holsaticum in one of the seawater systems used in this project, being the first report of this Mycobacterium species shown to be present in a fish.

Collaborative and partnership research for improvement of health and social services: researcher's experiences from 20 projects

BACKGROUND

Getting research into policy and practice in healthcare is a recognised, world-wide concern. As an attempt to bridge the gap between research and practice, research funders are requesting more interdisciplinary and collaborative research, while actual experiences of such processes have been less studied. Accordingly, the purpose of this study was to gain more knowledge on the interdisciplinary, collaborative and partnership research process by investigating researchers' experiences of and approaches to the process, based on their participation in an inventive national research programme. The programme aimed to boost collaborative and partnership research and build learning structures, while improving ways to lead, manage and develop practices in Swedish health and social services.

METHODS

Interviews conducted with project leaders and/or lead researchers and documentation from 20 projects were analysed using directed and conventional content analysis.

RESULTS

Collaborative approaches were achieved by design, e.g. action research, or by involving practitioners from several levels of the healthcare system in various parts of the research process. The use of dual roles as researcher/clinician or practitioner/PhD student or the use of education designed especially for practitioners or 'student researchers' were other approaches. The collaborative process constituted the area for the main lessons learned as well as the main problems. Difficulties concerned handling complexity and conflicts between different expectations and demands in the practitioner's and researcher's contexts, and dealing with human resource issues and group interactions when forming collaborative and interdisciplinary research teams. The handling of such challenges required time, resources, knowledge, interactive learning and skilled project management.

CONCLUSIONS

Collaborative approaches are important in the study of complex phenomena. Results from this study show that allocated time, arenas for interactions and skills in project management and communication are needed during research collaboration to ensure support and build trust and understanding with involved practitioners at several levels in the healthcare system. For researchers, dealing with this complexity takes time and energy from the scientific process. For practitioners, this puts demands on understanding a research process and how it fits with on-going organisational agendas and activities and allocating time. Some of the identified factors may be overlooked by funders and involved stakeholders when designing, performing and evaluating interdisciplinary, collaborative and partnership research.

ERAP1-Dependent Antigen Cross-Presentation Determines Efficacy of Adoptive T-cell Therapy in Mice

Cytotoxic T lymphocytes can reject established tumors if their target peptide is efficiently presented by MHC class I molecules (pMHC-I) on the surface of cancerous cells. Therapeutic success upon adoptive T-cell transfer (ATT), however, requires additional cross-presentation of the same pMHC-I on noncancerous cells. Endoplasmic reticulum aminopeptidase 1 (ERAP1) is an enzyme that customizes the N-terminus of proteasome-generated peptides so they can be loaded onto MHC-I molecules in the endoplasmic reticulum (ER). We show here that ERAP1 is critically involved in the process of tumor rejection and assumes a dual role by independently operating on both sides. Direct presentation of two MHC-I-restricted epitopes of a cancer-driving transplantation rejection antigen through ERAP1 moderately affected tumor rejection by adoptively transferred T-cell receptor gene-modified T cells in each case. ERAP1 expression by antigen cross-presenting cells of the ATT recipients was critical for expansion of therapeutic monospecific T cells and correlated with tumor rejection. Specifically, lack of ERAP1 expression in the ATT recipient's noncancerous cells enabled progression of pMHC-I-positive, IFNγ-responsive tumors, despite the presence of antigen-specific functional cytotoxic T lymphocytes. These data reveal a decisive role for ERAP1 in T-cell-mediated tumor rejection and will enhance the choice of MHC-I-restricted epitopes targeted by adoptive T-cell transfer.Significance: This study demonstrates a role of ERAP1 in the efficacy of adoptive T-cell transfer and has potential to improve personalized T-cell therapy for solid tumors. Cancer Res; 78(12); 3243-54. ©2018 AACR.

Preventing tumor escape by targeting a post-proteasomal trimming independent epitope

Blankenstein and colleagues describe a novel strategy to avoid tumor escape from adoptive T cell therapy.

Adoptive T cell therapy (ATT) can achieve regression of large tumors in mice and humans; however, tumors frequently recur. High target peptide-major histocompatibility complex-I (pMHC) affinity and T cell receptor (TCR)-pMHC affinity are thought to be critical to preventing relapse. Here, we show that targeting two epitopes of the same antigen in the same cancer cells via monospecific T cells, which have similar pMHC and pMHC-TCR affinity, results in eradication of large, established tumors when targeting the apparently subdominant but not the dominant epitope. Only the escape but not the rejection epitope required postproteasomal trimming, which was regulated by IFN-γ, allowing IFN-γ–unresponsive cancer variants to evade. The data describe a novel immune escape mechanism and better define suitable target epitopes for ATT.

CD8(+) T cells of Listeria monocytogenes-infected mice recognize both linear and spliced proteasome products

CD8(+) T cells responding to infection recognize pathogen-derived epitopes presented by MHC class-I molecules. While most of such epitopes are generated by proteasome-mediated antigen cleavage, analysis of tumor antigen processing has revealed that epitopes may also derive from proteasome-catalyzed peptide splicing (PCPS). To determine whether PCPS contributes to epitope processing during infection, we analyzed the fragments produced by purified proteasomes from a Listeria monocytogenes polypeptide. Mass spectrometry identified a known H-2K(b) -presented linear epitope (LLO296-304 ) in the digests, as well as four spliced peptides that were trimmed by ERAP into peptides with in silico predicted H-2K(b) binding affinity. These spliced peptides, which displayed sequence similarity with LLO296-304 , bound to H-2K(b) molecules in cellular assays and one of the peptides was recognized by CD8(+) T cells of infected mice. This spliced epitope differed by one amino acid from LLO296-304 and double staining with LLO296-304 - and spliced peptide-folded MHC multimers showed that LLO296-304 and its spliced variant were recognized by the same CD8(+) T cells. Thus, PCPS multiplies the variety of peptides that is processed from an antigen and leads to the production of epitope variants that can be recognized by cross-reacting pathogen-specific CD8(+) T cells. Such mechanism may reduce the chances for pathogen immune evasion.

Silicon alleviates Cd stress of wheat seedlings (Triticum turgidum L. cv. Claudio) grown in hydroponics

We investigated the potential role of silicon in improving tolerance and decreasing cadmium (Cd) toxicity in durum wheat (Triticum turgidum L. durum) either through a reduced Cd uptake or exclusion/sequestration in non-metabolic tissues. For this, plants were grown in hydroponic conditions for 10 days either in presence or absence of 1 mM Si and for 11 additional days in various Cd concentrations (0, 0.5, 5.0 and 50 μM). After harvesting, morphological and physiological parameters as well as elemental concentrations were recorded. Cadmium caused reduction in growth parameters, photosynthetic pigments and mineral nutrient concentrations both in shoots and roots. Shoot and root contents of malate, citrate and aconitate increased, while contents of phosphate, nitrate and sulphate decreased with increasing Cd concentrations in plants. Addition of Si to the nutrient solution mitigated these adverse effects: Cd concentration in shoots decreased while concentration of Cd adsorbed at the root cell apoplasmic level increased together with Zn uptake by roots. Overall, total Cd uptake decreased in presence of Si. There was no co-localisation of Cd and Si either at the shoot or at the root levels. No Cd was detected in leaf phytoliths. In roots, Cd was mainly detected in the cortical parenchyma and Si at the endodermis level, while analysis of the outer thin root surface of the plants grown in the 50 μM Cd + 1 mM Si treatment highlighted non-homogeneous Cd and Si enrichments. These data strongly suggest the existence of a root localised protection mechanism consisting in armoring the root surface by Si- and Cd-bearing compounds and in limiting root-shoot translocation.

The T210M Substitution in the HLA-a*02:01 gp100 Epitope Strongly Affects Overall Proteasomal Cleavage Site Usage and Antigen Processing

MHC class I-restricted epitopes, which carry a tumor-specific mutation resulting in improved MHC binding affinity, are preferred T cell receptor targets in innovative adoptive T cell therapies. However, T cell therapy requires efficient generation of the selected epitope. How such mutations may affect proteasome-mediated antigen processing has so far not been studied. Therefore, we analyzed by in vitro experiments the effect on antigen processing and recognition of a T210M exchange, which previously had been introduced into the melanoma gp100209-217 tumor epitope to improve the HLA-A*02:01 binding and its immunogenicity. A quantitative analysis of the main steps of antigen processing shows that the T210M exchange affects proteasomal cleavage site usage within the mutgp100201-230 polypeptide, leading to the generation of an unique set of cleavage products. The T210M substitution qualitatively affects the proteasome-catalyzed generation of spliced and non-spliced peptides predicted to bind HLA-A or -B complexes. The T210M substitution also induces an enhanced production of the mutgp100209-217 epitope and its N-terminally extended peptides. The T210M exchange revealed no effect on ERAP1-mediated N-terminal trimming of the precursor peptides. However, mutant N-terminally extended peptides exhibited significantly increased HLA-A*02:01 binding affinity and elicited CD8(+) T cell stimulation in vitro similar to the wtgp100209-217 epitope. Thus, our experiments demonstrate that amino acid exchanges within an epitope can result in the generation of an altered peptide pool with new antigenic peptides and in a wider CD8(+) T cell response also towards N-terminally extended versions of the minimal epitope.

The proteasome immunosubunits, PA28 and ER-aminopeptidase 1 protect melanoma cells from efficient MART-126-35 -specific T-cell recognition

The immunodominant MART-1(26(27)-35) epitope, liberated from the differentiation antigen melanoma antigen recognized by T cells/melanoma antigen A (MART-1/Melan-A), has been frequently targeted in melanoma immunotherapy, but with limited clinical success. Previous studies suggested that this is in part due to an insufficient peptide supply and epitope presentation, since proteasomes containing the immunosubunits β5i/LMP7 (LMP, low molecular weight protein) or β1i/LMP2 and β5i/LMP7 interfere with MART-1(26-35) epitope generation in tumor cells. Here, we demonstrate that in addition the IFN-γ-inducible proteasome subunit β2i/MECL-1 (multicatalytic endopeptidase complex-like 1), proteasome activator 28 (PA28), and ER-resident aminopeptidase 1 (ERAP1) impair MART-1(26-35) epitope generation. β2i/MECL-1 and PA28 negatively affect C- and N-terminal cleavage and therefore epitope liberation from the proteasome, whereas ERAP1 destroys the MART-1(26-35) epitope by overtrimming activity. Constitutive expression of PA28 and ERAP1 in melanoma cells indicate that both interfere with MART-1(26-35) epitope generation even in the absence of IFN-γ. In summary, our results provide first evidence that activities of different antigen-processing components contribute to an inefficient MART-1(26-35) epitope presentation, suggesting the tumor cell's proteolytic machinery might have an important impact on the outcome of epitope-specific immunotherapies.

The immunoproteasome β5i subunit is a key contributor to ictogenesis in a rat model of chronic epilepsy

The proteasome is the core of the ubiquitin-proteasome system and is involved in synaptic protein metabolism. The incorporation of three inducible immuno-subunits into the proteasome results in the generation of the so-called immunoproteasome, which is endowed of pathophysiological functions related to immunity and inflammation. In healthy human brain, the expression of the key catalytic β5i subunit of the immunoproteasome is almost absent, while it is induced in the epileptogenic foci surgically resected from patients with pharmaco-resistant seizures, including temporal lobe epilepsy. We show here that the β5i immuno-subunit is induced in experimental epilepsy, and its selective pharmacological inhibition significantly prevents, or delays, 4-aminopyridine-induced seizure-like events in acute rat hippocampal/entorhinal cortex slices. These effects are stronger in slices from epileptic vs normal rats, likely due to the more prominent β5i subunit expression in neurons and glia cells of diseased tissue. β5i subunit is transcriptionally induced in epileptogenic tissue likely by Toll-like receptor 4 signaling activation, and independently on promoter methylation. The recent availability of selective β5i subunit inhibitors opens up novel therapeutic opportunities for seizure inhibition in drug-resistant epilepsies.

Effect of silicon on wheat seedlings (Triticum turgidum L.) grown in hydroponics and exposed to 0 to 30 µM Cu

Aqueous Si limits Cu uptake by a Si-accumulating plant via physicochemical mechanisms occurring at the root level. Sufficient Si supply may alleviate Cu toxicity in Cu-contaminated soils. Little information is available on the role of silicon (Si) in copper (Cu) tolerance while Cu toxicity is widespread in crops grown on Cu-contaminated soils. A hydroponic study was set up to investigate the influence of Si on Cu tolerance in durum wheat (Triticum turgidum L.) grown in 0, 0.7, 7.0 and 30 µM Cu without and with 1.0 mM Si, and to identify the mechanisms involved in mitigation of Cu toxicity. Si supply alleviated Cu toxicity in durum wheat at 30 µM Cu, while Cu significantly increased Si concentration in roots. Root length, photosynthetic pigments concentrations, macroelements, and organic anions (malate, acetate and aconitate) in roots, were also increased. Desorption experiments, XPS analysis of the outer thin root surface (≤100 Å) and µXRF analyses showed that Si increased adsorption of Cu at the root surface as well as Cu accumulation in the epidermis while Cu was localised in the central cylinder when Si was not applied. Copper was not detected in phytoliths. This study provides evidences for Si-mediated alleviation of Cu toxicity in durum wheat. It also shows that Si supplementation to plants exposed to increasing levels of Cu in solution induces non-simultaneous changes in physiological parameters. We propose a three-step mechanism occurring mainly at the root level and limiting Cu uptake and translocation to shoots: (i) increased Cu adsorption onto the outer thin layer root surface and immobilisation in the vicinity of root epidermis, (ii) increased Cu complexation by both inorganic and organic anions such as aconitate and, (iii) limitation of translocation through an enhanced thickening of a Si-loaded endodermis.

Adult human liver contains intermediate-type proteasomes with different enzymatic properties

BACKGROUND

The 20S proteasome is the proteolytic core of the major intracellular protein degradative system, the ubiquitin-proteasome system. Since little is known about proteasomes of human liver, we have investigated the proteasome spectrum in adult human liver.

MATERIAL AND METHODS

20S proteasomes were chromatographically purified from adult human liver and from HuH7 cells. They were divided into subpopulations and subtypes and characterized with regard to their proteolytic activities using short fluorogenic oligo- and long poly-peptide substrates. Their subunit composition was studied by immunoblotting.

RESULTS

Proteasomes from adult human liver tissue can be separated into three subpopulations (I, II, III), each of which is composed of several subtypes, which total to a spectrum of 14 different subtypes. Two minor subtypes contain only the immuno-subunits β1i and β5i but not their standard counterparts; all others are intermediate subtypes containing β1 and β5 standard- and β1i and β5i immuno-subunits in various compositions. With regard to the proteolytic activities we observed that a decreasing content of subunit β1i in the subtypes goes along with a decreasing ratio of chymotrypsin-like/caspase-like activity, whereas the degradation rate of a 30 mer polypeptide substrate increased with decreasing β1i content. By comparison, 20S proteasomes from HuH7 cells do not contain immuno-subunits but are pure standard proteasomes, which can be separated into three subtypes.

CONCLUSION

These findings suggest that adult human liver contains a spectrum of 14 different 20S proteasome subtypes with different enzymatic properties reflecting most probably an adaptive response of liver cell functions to challenging factors during lifetime.

Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater

The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil.

Proteasome isoforms exhibit only quantitative differences in cleavage and epitope generation

Immunoproteasomes are considered to be optimised to process Ags and to alter the peptide repertoire by generating a qualitatively different set of MHC class I epitopes. Whether the immunoproteasome at the biochemical level, influence the quality rather than the quantity of the immuno-genic peptide pool is still unclear. Here, we quantified the cleavage-site usage by human standard- and immunoproteasomes, and proteasomes from immuno-subunit-deficient mice, as well as the peptides generated from model polypeptides. We show in this study that the different proteasome isoforms can exert significant quantitative differences in the cleavage-site usage and MHC class I restricted epitope production. However, independent of the proteasome isoform and substrates studied, no evidence was obtained for the abolishment of the specific cleavage-site usage, or for differences in the quality of the peptides generated. Thus, we conclude that the observed differences in MHC class I restricted Ag presentation between standard- and immunoproteasomes are due to quantitative differences in the proteasome-generated antigenic peptides.

[Two forms of familial hypercholesterolemia: differences in cardiovascular risk factors, cardiac and extracardiac atherosclerosis]

BACKGROUND AND AIM

The monogenetic hypercholesterolemias (HC) are associated with a very high risk of premature coronary heart disease (CHD). We sought to assess the influence of the genetic defect and the cardiovascular risk factors on the manifestation of atherosclerotic complications in two forms of genetic HC.

PATIENTS AND METHODS

Data of patients with genetically defined HC (54 LDL-receptor defective familial hypercholesterolemia (FH) and 54 familial defective apolipoprotein B (FDB)) were analysed retrospectively for cardiac and extracardiac atherosclerosis.

RESULTS

Total and LDL-cholesterol were significantly higher in FH men than in FDB men, but not so in women. 41.8% of FH patients had CHD (mean age 41 years), 5.6% of FDB (mean age 52 years). Stenoses (>50% narrowing) of the internal carotid artery were verified in 15% of FH and 4% of FDB patients. Peripheral arterial disease was found in 3 FH and 2 FDB patients. Hypertension and active smoking were allotted almost equally, body weight was normal in most of the patients (BMI ≤ 25 kg/m(2)). Conlusion: Patients with genetic HC suffer from early manifestation of cardiac disease. Patients with FH seem to be affected more often than patients with FDB. Early diagnosis and early and lifelong treatment are essential and, according to the literature, lead to a delay of disease manifestation.

Zum Einbau von einigen Lanthaniden in Gd2Cl3 / Incorporation of Some Lanthanides into Gd2Cl3

Co-crystallization experiments with radioactive isotopes of lanthanides (Ce, Nd, Eu, Gd, Tb, Dy, Tm, Yb) show that only Tb is incorporated by Gd2Cl3 in a significant amount. The results are discussed in terms of the electronic configuration of Ln2+ ions as well as redox potentials E°(Ln3+/Ln2+).

[Muscular sarcocystosis after travel to Malaysia: a case series from Germany]

BACKGROUND

Since 2011, about 100 travellers to the island of Tioman, Malaysia, have been diagnosed worldwide with suspected muscular sarcocystosis, a previously only sporadically observed parasitic disease. Source of infection and therapy remain unclear. Final diagnosis requires microscopic identification of cysts in muscle biopsies. The study objective was a systematic description of characteristic symptoms, laboratory investigations and treatment response.

METHODS

Systematic case series.

RESULTS

The 26 cases of 5 centers for tropical medicine in Germany showed a characteristic biphasic development: symptoms began in general 2 weeks after mid-holidays (min. 7.5, max. 22 days) with unspecific fever and headaches lasting for almost 1 week. After an asymptomatic period of 2 weeks, severe myalgia (6.5, scale 0-10) and fever developed and lasted for about 6 weeks (min. 7, max. 207 days), accompanied by creatin-phosphokinase(CK)-elevation (up to 3.5 times), and eosinophilia (2.9 times). One out of two muscle biopsies revealed a cyst typical for sarcocystosis. In 6 out of 7 patients an increase in Sarcocystis-specific antibody concentration could be demonstrated by ELISA. Treatment with systemic steroids and albendazole, or ivermectin resulted in significant symptomatic improvement in most of the patients. One patient was treated early with cotrimoxazole and subsequently did not develop a second phase of the disease. All patients had stayed in the North-West of the island Tioman.

CONCLUSIONS

Muscular sarcocystosis develops in a biphasic pattern with initial fever and later prolonged myalgia, eosinophilia, and CK-elevation. Steroids achieve symptomatic relief in the late phase. Early cotrimoxazole-therapy could possibly prevent parasitic muscle invasion. In fever after travel to Malaysia differential diagnosis should include sarcocystosis. The source of infection appears to be located in North-West of Tioman. Further studies are needed, including addressing early diagnosis and treatment.

Molecular alterations in proteasomes of rat liver during aging result in altered proteolytic activities

Aging induces alterations of tissue protein homoeostasis. To investigate one of the major systems catalysing intracellular protein degradation we have purified 20S proteasomes from rat liver of young (2 months) and aged (23 months) animals and separated them into three subpopulations containing different types of intermediate proteasomes with standard- and immuno-subunits. The smallest subpopulation ΙΙΙ and the major subpopulation Ι comprised proteasomes containing immuno-subunits β1i and β5i beside small amounts of standard-subunits, whereas proteasomes of subpopulation ΙΙ contained only β5i beside standard-subunits. In favour of a relative increase of the major subpopulation Ι, subpopulation ΙΙ and ΙΙΙ were reduced for about 55 % and 80 %, respectively, in aged rats. Furthermore, in all three 20S proteasome subpopulations from aged animals standard-active site subunits were replaced by immuno-subunits. Overall, this transformation resulted in a relative increase of immuno-subunit-containing proteasomes, paralleled by reduced activity towards short fluorogenic peptide substrates. However, depending on the substrate their hydrolysing activity of long polypeptide substrates was significantly higher or unchanged. Furthermore, our data revealed an altered MHC class I antigen-processing efficiency of 20S proteasomes from liver of aged rats. We therefore suggest that the age-related intramolecular alteration of hepatic proteasomes modifies its cleavage preferences without a general decrease of its activity. Such modifications could have implications on protein homeostasis as well as on MHC class I antigen presentation as part of the immunosenescence process.

Three cases of donor-derived pulmonary tuberculosis in lung transplant recipients and review of 12 previously reported cases: opportunities for early diagnosis and prevention

INTRODUCTION

Solid organ transplant recipients have a higher frequency of tuberculosis (TB) than the general population, with mortality rates of approximately 30%. Although donor-derived TB is reported to account for <5% of TB in solid organ transplants, the source of Mycobacterium tuberculosis infection is infrequently determined.

METHODS

We report 3 new cases of pulmonary TB in lung transplant recipients attributed to donor infection, and review the 12 previously reported cases to assess whether cases could have been prevented and whether any cases that might occur in the future could be detected and investigated more quickly. Specifically, we evaluate whether opportunities existed to determine TB risk on the basis of routine donor history, to expedite diagnosis through routine mycobacterial smears and cultures of respiratory specimens early post transplant, and to utilize molecular tools to investigate infection sources epidemiologically.

FINDINGS

On review, donor TB risk was present among 7 cases. Routine smears and cultures diagnosed 4 asymptomatic cases. Genotyping was used to support epidemiologic findings in 6 cases.

CONCLUSION

Validated screening protocols, including microbiological testing and newer technologies (e.g., interferon-gamma release assays) to identify unrecognized M. tuberculosis infection in deceased donors, are warranted.