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Abstract Key message Appropriate silvicultural practices combined with the use of resistant Central European provenances can reduce the prevalence of larch canker caused by Lachnellula willkommii (R. Hartig) Dennis, a major disease affecting larch plantations in France. However, cascading translocations have resulted in frequent admixture in European larch (Larix decidua Mill.) and subsequent certification errors regarding the origin of plant material. Our study highlights the urgent need to improve the certification process of seed orchards. Context The recent history of European larch has been marked by translocations of plant stock within and beyond its native range. In order to increase stand resistance to larch canker disease, it is strongly recommended by French authorities to plant Central European provenances. However, a recent disease outbreak questioned the resistance of Central European provenances and the origin of the forest material used in these plantations. Aims Our goal was to assess the effects of cascading translocations and mixing between larch gene pools on genetic composition of plantations and on their vulnerability to the disease. Methods In the outbreak area, we checked the genetic origin of the trees and we estimated the percentage of Central European trees, disease prevalence and severity. Results Intra-site genetic diversity was high. Genetic composition did not match with geographic origin certificates. A high proportion of trees could not be assigned to either the Alpine or Central European gene pools. These admixed trees were as resistant as Central European trees. Geographic origin turned out to be one of the main drivers of canker prevalence, along with abiotic factors. Conclusion We need a precise knowledge of the origin of material used in seed orchards to mitigate canker disease and adapt forests through assisted migration.

ObjectiveSutureless aortic valves are an effective option for aortic valve replacement (AVR) showing non-inferiority to standard stented aortic valves for major cardiovascular and cerebral events at 1-year. We report the 1-year hemodynamic performance of the sutureless prostheses compared with standard aortic valves, assessed by a dedicated echocardiographic core lab.MethodsPerceval Sutureless Implant vs. Standard Aortic Valve Replacement (PERSIST-AVR) is a prospective, randomized, adaptive, open-label trial. Patients undergoing AVR, as an isolated or combined procedure, were randomized to receive a sutureless [sutureless aortic valve replacement (Su-AVR)] (n = 407) or a stented sutured [surgical AVR (SAVR)] (n = 412) bioprostheses. Site-reported echocardiographic examinations were collected at 1 year. In addition, a subgroup of the trial population (Su-AVR n = 71, SAVR = 82) had a complete echocardiographic examination independently assessed by a Core Lab (MedStar Health Research Institute, Washington D.C., USA) for the evaluation of the hemodynamic performance.ResultsThe site-reported hemodynamic data of stented valves and sutureless valves are stable and comparable during follow-up, showing stable reduction of mean and peak pressure gradients through one-year follow-up (mean: 12.1 ± 6.2 vs. 11.5 ± 4.6 mmHg; peak: 21.3 ± 11.4 vs. 22.0 ± 8.9 mmHg). These results at 1-year are confirmed in the subgroup by the core-lab assessed echocardiogram with an average mean and peak gradient of 12.8 ± 5.7 and 21.5 ± 9.1 mmHg for Su-AVR, and 13.4 ± 7.7 and 23.0 ± 13.0 mmHg for SAVR. The valve effective orifice area was 1.3 ± 0.4 and 1.4 ± 0.4 cm2 at 1-year for Su-AVR and SAVR. These improvements are observed across all valve sizes. At 1-year evaluation, 91.3% (n = 42) of patients in Su-AVR and 82.3% in SAVR (n = 51) groups were free from paravalvular leak (PVL). The rate of mild PVL was 4.3% (n = 2) in Su-AVR and 12.9% (n = 8) in the SAVR group. A similar trend is observed for central leak occurrence in both core-lab assessed echo groups.ConclusionAt 1-year of follow-up of a PERSIST-AVR patient sub-group, the study showed comparable hemodynamic performance in the sutureless and the stented-valve groups, confirmed by independent echo core lab. Perceval sutureless prosthesis provides optimal sealing at the annulus with equivalent PVL and central regurgitation extent rates compared to sutured valves. Sutureless valves are therefore a reliable and essential technology within the modern therapeutic possibilities to treat aortic valve disease.

Ribosomal Intergenic Spacer Analysis (RISA) is a high-resolution and highly reproducible fingerprinting technique for discriminating between microbial communities. The community profiles can be visualized using the Agilent 2100 Bioanalyzer. Comparison between fingerprints relies upon precise estimation of all amplified DNA fragment lengths; however, size standard computation can vary between gel runs. For complex samples such as soil microbial communities, discrimination by fragment size is not always sufficient. In such cases, the comparison of whole fluorescence data as a function of time (electrophoregrams) is more appropriate. When electrophoregrams [fluorescence = f (time)] are used, and more than one chip is involved, electrophoregram comparisons are challenging due to experimental variations between chips and the lack of correction by the Agilent software in such situations. Here we present RisaAligner software for analyzing and comparing electrophoregrams from Agilent chips using a nonlinear ladder-alignment algorithm. We demonstrate the robustness and substantial improvement of data analysis by analyzing soil microbial profiles obtained with Agilent DNA 1000 and High Sensitivity chips.

The region of Soloco, located in the North of the Peruvian ceja de selva, was occupied between 800 ac. J.-C. and 1470 ac. J.-C. by a population belonging to the tradition chachapoya. Among the various pre-Hispanic establishments, strewing the archaeological landscape, the site of Chaquil is located near the eponymous cave of Chaquil. Various archaeological and caving missions, aiming at investigating and mapping the subterranean networks of the Soloco area, allowed to bring to light the presence of numerous human bones inside this cave which give evidence of the pre-Hispanic use of caves as place of burial.

Injection of autologous bone marrow cells into infarcted myocardium has been proposed to limit the deterioration of cardiac function following myocardial infarction (MI); unfortunately, the beneficial effects observed have been modest. One of the limiting factors is believed to be poor local survival of the injected cells, but the potential impact of apoptosis among the injected cells has yet to be assessed. Therefore, this study aimed to quantify the apoptosis rate in bone marrow mononuclear cells (BMMCs) prepared for cardiac therapy, and to analyze their effects in vitro on cardiomyoblast apoptosis and in vivo on cardiac function recovery following MI. Using rabbit BMMCs prepared by Ficoll gradient, apoptotic cells were detected via Annexin V (AnV) staining. The effects of depleting the apoptotic cell population by means of AnV magnetic beads was tested in vitro after coculture with cardiomyoblasts (H9c2 cells) and in vivo after cell injection into the infarcted area. Left ventricular ejection fraction and scar extent were assessed by echography and histology 2 months later. After Ficoll gradient isolation, 37.3% (33.4–37.9%) of BMMCs were found to be apoptotic (Apo Base BMMCs). AnV depletion decreased the proportion of apoptotic cells to 20% (17.6–32%) (Apo Low BMMCs). Rabbits treated in vivo with Apo Low BMMCs after MI presented with significantly improved left ventricular ejection fraction [41.4% (41.0–43.6%) vs. 34.6% (34.6–35.9%), p = 0.03), reduced scar extent [20.4% (17.9–24.3%) vs. 25.6% (17.9–27.9%), p = 0.057], and reduced rate of cardiomyocyte apoptosis compared to those treated with Apo Base BMMCs. H9c2 apoptosis was found to be higher after coculture with Apo Base than with Apo Low BMMCs [25.6% (22.6–29.6%) vs. 10.1% (6.6–12.6%), p = 0.03], a result partially reproduced by cocultures with microparticle-rich supernatants from BMMCs. The presence of apoptotic cells among BMMCs impairs the efficacy of cardiac cell therapy after MI, an effect possibly mediated by apoptotic microparticles.

Population-level dynamics of host-pathogen interactions can be characterized using quantitative live-cell imaging. Here, we present a protocol for infecting macrophages with the fungal pathogen Candida albicans in vitro and quantitative live-cell imaging of immune and pathogen responses. We describe steps for detailed image analysis and provide resources for quantification of phagocytosis and pathogen escape, as well as macrophage membrane permeabilization and viability. This protocol is modifiable for applications with a range of pathogens, immune cell types, and host-pathogen mechanisms. For complete details on the use and execution of this protocol, please refer to Olivier et al. 1 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Metabolic adaptations regulate the response of macrophages to infection. The contributions of metabolism to macrophage interactions with the emerging fungal pathogen Candida auris are poorly understood. Here, we show that C. auris-infected macrophages undergo immunometabolic reprogramming and increase glycolysis but fail to activate a strong interleukin (IL)-1β cytokine response or curb C. auris growth. Further analysis shows that C. auris relies on its own metabolic capacity to escape from macrophages and proliferate in vivo. Furthermore, C. auris kills macrophages by triggering host metabolic stress through glucose starvation. However, despite causing macrophage cell death, C. auris does not trigger robust activation of the NLRP3 inflammasome. Consequently, inflammasome-dependent responses remain low throughout infection. Collectively, our findings show that C. auris uses metabolic regulation to eliminate macrophages while remaining immunologically silent to ensure its own survival. Thus, our data suggest that host and pathogen metabolism could represent therapeutic targets for C. auris infections., Competing Interests: Declaration of interests D.S. received honoraria and/or sat on advisory boards of Gilead, MSD, GSK, Pfizer, and Astra Zeneca. R.B.-M. served on advisory boards for Pfizer and Merck and received compensation from Teva and Gilead for lectures., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Fungal pathogens overcome antifungal drug therapy by classic resistance mechanisms, such as increased efflux or changes to the drug target. However, even when a fungal strain is susceptible, trailing or persistent microbial growth in the presence of an antifungal drug can contribute to therapeutic failure. This trailing growth is caused by adaptive physiological changes that enable the growth of a subpopulation of fungal cells in high drug concentrations, in what is described as drug tolerance. Mechanistically, antifungal drug tolerance is incompletely understood. Here we report that the transcriptional activator Rpn4 is important for drug tolerance in the human fungal pathogen Candida albicans. Deletion of RPN4 eliminates tolerance to the commonly used antifungal drug fluconazole. We defined the mechanism and show that Rpn4 controls fluconazole tolerance via two target pathways. First, Rpn4 activates proteasome gene expression, which enables sufficient proteasome capacity to overcome fluconazole-induced proteotoxicity and the accumulation of ubiquitinated proteins targeted for degradation. Consistently, inhibition of the proteasome with MG132 eliminates fluconazole tolerance and resistance, and phenocopies the rpn4Δ/Δ mutant for loss of tolerance. Second, Rpn4 is required for wild type expression of the genes required for the synthesis of the membrane lipid ergosterol. Our data indicates that this function of Rpn4 is required for mitigating the inhibition of ergosterol biosynthesis by fluconazole. Based on our findings, we propose that Rpn4 is a central hub for fluconazole tolerance in C. albicans by coupling the regulation of protein homeostasis (proteostasis) and lipid metabolism to overcome drug-induced proteotoxicity and membrane stress., Competing Interests: The authors do not have any competing interests., (Copyright: © 2023 Yau et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The egress of Candida hyphae from macrophages facilitates immune evasion, but it also alerts macrophages to infection and triggers inflammation. To better define the mechanisms, here we develop an imaging assay to directly and dynamically quantify hyphal escape and correlate it to macrophage responses. The assay reveals that Candida escapes by using two pore-forming proteins to permeabilize macrophage membranes: the fungal toxin candidalysin and Nlrp3 inflammasome-activated Gasdermin D. Candidalysin plays a major role in escape, with Nlrp3 and Gasdermin D-dependent and -independent contributions. The inactivation of Nlrp3 does not reduce hyphal escape, and we identify ETosis via macrophage extracellular trap formation as an additional pathway facilitating hyphal escape. Suppressing hyphal escape does not reduce fungal loads, but it does reduce inflammatory activation. Our findings explain how Candida escapes from macrophages by using three strategies: permeabilizing macrophage membranes via candidalysin and engaging two host cell death pathways, Gasdermin D-mediated pyroptosis and ETosis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Antimicrobial volatile organic compounds (VOCs) may provide fungi an advantage over other competing microorganisms. As these defensive metabolites are often produced in response to microbial competitors, they are easily overlooked in axenic cultures. We used media supplemented with spent medium from Candida albicans to induce the expression of a broad-spectrum antimicrobial response in a previously uncharacterised white-rot fungus, Scytinostroma sp. Crude extractions of Scytinostroma sp. metabolites were found to be cytotoxic to fibroblast cells and antimicrobial to filamentous fungi, yeasts and Gram-positive bacteria. Volatile antimicrobial activity was observed for Scytinostroma sp. cultures and metabolite extracts using antimicrobial assays in bi-compartmentalised plates. Culture headspace analysis using solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) revealed a pronounced shift in Scytinostroma sp. VOCs when cultured on media supplemented with C. albicans spent medium. We observed a significant increase in the levels of 45 identified VOCs, including 7 metabolites with reported antimicrobial activity. Using preparative HPLC combined with GC-MS, we determined that isovelleral is likely to be the main broad-spectrum antimicrobial metabolite produced by Scytinostroma sp. Isovelleral is a sesquiterpene dialdehyde with both antibiotic and antifeedant properties, previously detected in fruit bodies of other Basidiomycetes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Staphylococcus aureus causes necrotizing pneumonia by secreting toxins such as leukocidins that target front-line immune cells. The mechanism by which leukocidins kill innate immune cells and trigger inflammation during S. aureus lung infection, however, remains unresolved. Here, we explored human-induced pluripotent stem cell-derived macrophages (hiPSC-dMs) to study the interaction of the leukocidins Panton-Valentine leukocidin (PVL) and LukAB with lung macrophages, which are the initial leukocidin targets during S. aureus lung invasion. hiPSC-dMs were susceptible to the leukocidins PVL and LukAB and both leukocidins triggered NLPR3 inflammasome activation resulting in IL-1β secretion. hiPSC-dM cell death after LukAB exposure, however, was only temporarily dependent of NLRP3, although NLRP3 triggered marked cell death after PVL treatment. CRISPR/Cas9-mediated deletion of the PVL receptor, C5aR1, protected hiPSC-dMs from PVL cytotoxicity, despite the expression of other leukocidin receptors, such as CD45. PVL-deficient S. aureus had reduced ability to induce lung IL-1β levels in human C5aR1 knock-in mice. Unexpectedly, inhibiting NLRP3 activity resulted in increased wild-type S. aureus lung burdens. Our findings suggest that NLRP3 induces macrophage death and IL-1β secretion after PVL exposure and controls S. aureus lung burdens., (©2020 Society for Leukocyte Biology.)

The NLRP3 inflammasome has emerged as a central immune regulator that senses virulence factors expressed by microbial pathogens for triggering inflammation. Inflammation can be harmful and therefore this response must be tightly controlled. The mechanisms by which immune cells, such as macrophages, discriminate benign from pathogenic microbes to control the NLRP3 inflammasome remain poorly defined. Here we used live cell imaging coupled with a compendium of diverse clinical isolates to define how macrophages respond and activate NLRP3 when faced with the human yeast commensal and pathogen Candida albicans. We show that metabolic competition by C. albicans, rather than virulence traits such as hyphal formation, activates NLRP3 in macrophages. Inflammasome activation is triggered by glucose starvation in macrophages, which occurs when fungal load increases sufficiently to outcompete macrophages for glucose. Consistently, reducing Candida's ability to compete for glucose and increasing glucose availability for macrophages tames inflammatory responses. We define the mechanistic requirements for glucose starvation-dependent inflammasome activation by Candida and show that it leads to inflammatory cytokine production, but it does not trigger pyroptotic macrophage death. Pyroptosis occurs only with some Candida isolates and only under specific experimental conditions, whereas inflammasome activation by glucose starvation is broadly relevant. In conclusion, macrophages use their metabolic status, specifically glucose metabolism, to sense fungal metabolic activity and activate NLRP3 when microbial load increases. Therefore, a major consequence of Candida-induced glucose starvation in macrophages is activation of inflammatory responses, with implications for understanding how metabolism modulates inflammation in fungal infections., Competing Interests: The authors have declared that no competing interests exist. We note that MCC950 is a compound that is in the public domain. More broadly AABR is inventor on three patents on novel NLRP3 inhibitors:WO2016131098, WO2017140778, WO2018215818.