Is there a role for glucocorticoid receptor beta in asthma?

Glucocorticoids (GCs) are routinely used as anti-inflammatory drugs in the treatment of asthma. They act through binding to glucocorticoid receptor α (GRα), which represses numerous genes encoding pro-inflammatory mediators. A hormone binding deficient GR isoform named GRβ has been isolated in humans. When overexpressed by transfection, GRβ may function as a dominant negative modulator of GRα. However, to act as such, GRβ has to be more abundant than GRα, and conflicting data have been obtained concerning the relative levels of the two isoforms in cell lines and freshly isolated cells. Moreover, the dominant negative effect was not confirmed by independent laboratories. In GC-resistant asthmatics, GRβ was expressed by an increased number of peripheral blood mononuclear cells (PBMCs), airway T cells, and cells found in skin biopsies of tuberculin responses. However, the relative amounts of GRα and GRβ in these cells were not determined. In GC-dependent asthmatics, PBMCs expressed GRα predominantly. No cells containing higher levels of GRβ than GRα have yet been reported in asthmatics. Even if the existence of such cells is demonstrated, the role of GRβ in asthma will remain a matter of controversy because functional studies have given discrepant data

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe

Potent Ant Deterrents Emitted from Nematode-Infected Insect Cadavers

Most known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential

Identification of ant deterrents emitted by entomopathogenic nematode-infected insect cadavers

Trabajo presentado en el 34th annual meeting of the International Society of Chemical Ecology, celebrado en Budapest (Hungría), del 12 al 18 de agosto de 2018Peer reviewe

The lure of hidden death: Attractive volatile organic compounds to attract wireworms towards entomopathogenic nematodes

Trabajo presentado en el 52nd Annual Meeting of the Society for Invertebrate Pathology y 17th Meeting of the IOBC‐WPRS Working Group “Microbial and Nematode Control of Invertebrate Pests”, celebrado en Valencia (España), del 28 de julio al 1 de agosto de 201

The lure of hidden death: volatile organic compounds to attract wireworms towards entomopathogenic nematodes

Trabajo presentado en el 35th Meeting of the International Society of Chemical Ecology, celebrado en Georgia (Estados Unidos), del 2 al 7 de junio de 2019Wireworms (Coleoptera: Elateridae) ae) are common polyphagous soil pests. One strategy to control these pest insects could be an attract-and-kill system combining volatile organic compounds (VOCs), as attractants, and entomopathogenic nematodes as biocontrol agents

Efficiency of an attract-and-kill system with entomopathogenic nematodes against wireworms (Coleoptera: Elateridae)

Trabajo presentado en el 52nd Annual Meeting of the Society for Invertebrate Pathology y 17th Meeting of the IOBC‐WPRS Working Group “Microbial and Nematode Control of Invertebrate Pests”, celebrado en Valencia (España), del 28 de julio al 1 de agosto de 2019This study aimed at contributing to the development of an attract-and-kill strategy combining plant natural extracts with entomopathogenic nematodes (EPNs). We first compared the efficiency of two EPN strains through classical screening laboratory assays (contact application of EPNs) and found 8.3 and 16.7% of mortality after 10 days for Steinernema carpocapsae B14 and Heterorhabditis bacteriophora, respectively. Then, we encapsulated EPNs with potato extracts (acting as attractant and feeding stimulant) in alginate beads and the results showed higher mortality rates: 16.7% and 41.7% for S. carpocapsae and H. bacteriophora, respectively. In absence of attractants in the beads, the mortality dropped to 0% (S. carpocapsae) and 8.3% (H. bacteriophora). We conclude that the ingestion of EPN lead to increased mortality, compared to contact application of EPNs. The association of volatiles organic compounds as attractants and EPNs as biological agents represent a promising alternative to pesticides that remains to be evaluated in the field.D. la Forgia is supported by a PhD grant from Coordinated Integrated Pest Management in Europe (C-IPM), project ElatPro and a FNRS mobility grant. R. Campos-Herrera is awarded with a Ramón y Cajal contract (RYC-2016-19939

The evaluation of entomopathogenic nematode soil food web assemblages across Switzerland reveals major differences among agricultural, grassland and forest ecosystems

Entomopathogenic nematodes (EPNs) occur in natural and agricultural soils and contribute to the control of soil dwelling insect pests. Ecosystems differ in their soil parameters (pH, moisture, texture, etc.) and microhabitat conditions (presence of roots, plant cover, belowground fauna, etc.), which can affect the EPN soil food web assemblage in an unpredictable manner. By comparing soils that represent different ecological scenarios, we can link the natural distribution of the EPN to abiotic and biotic factors that shape the assemblages of soil food web to unravel the factors that determine EPN abundance and activity. We hypothesized that the EPN soil food web assemblages are affected by agricultural management practices and that this should be reflected when compared to natural ecosystems, such as forests and grasslands. By combining traditional and state-of-the-art molecular tools, we targeted 25 soil organisms to explore EPN food web in 40 Swiss georeferenced sites that can be categorized as “agricultural area”, “forest”, and “grassland”. EPNs abundance, richness and diversity did not vary among the different ecosystems. However, EPN activity (capability to kill insects) was higher in grasslands. Similarly, the free-living nematodes (FLNs) that compete with EPN for the cadavers were much more abundant in grassland, while reduced in the forest soils, suggesting contrasting conditions between these two natural areas. Nematophagous fungi (NF) were more diverse and present in agricultural areas, suggesting that the abiotic conditions in the agricultural areas may favor NF presence. Six soil properties and environmental factors shaped the EPN soil food web in Swiss soils (pH, elevation, clay content, soil water content, temperature, and rainfall), which explained 54% of the community variation in multivariate analysis. These observations were consistent with the key abiotic variables described for subtropical and Mediterranean regions. Identifying the links between the abiotic and biotic factors in very distinct areas can be the basis for predicting EPN soil food web assemblages. Such information can be of value for developing strategies to favour EPN resilience in a changing environment and enhance their capacity as biocontrol agents.This work was supported by an economic stimulus grant (51NF40-144621) and by the National Research Program 68 (NRP68) grant (406840_143065) from the Swiss National Science Foundation. GJ was supported by an assistantship from the University of Neuchâtel and XC was supported by a PhD fellowship from the Commission Fédérale des Bourses pour Etudiants Etrangères CFBE (Confédération Suisse). RCH was supported by The Government of Portugal (Investigator Program award, IF/00552/2014).Peer reviewe