Surviving the heat:Heterogeneity of response in Saccharomyces cerevisiae provides insight into thermal damage to the membrane

Environmental heat stress impacts on the physiology and viability of microbial cells with concomitant implications for microbial activity and diversity. Previously, it has been demonstrated that gradual heating of Saccharomyces cerevisiae induces a degree of thermal resistance, whereas a heat shock results in a high level of cell death. Here, we show that the impact of exogenous nutrients on acquisition of thermal resistance differs between strains. Using single-cell methods, we demonstrate the extent of heterogeneity of the heat-stress response within populations of yeast cells and the presence of subpopulations that are reversibly damaged by heat stress. Such cells represent potential for recovery of entire populations once stresses are removed. The results show that plasma membrane permeability and potential are key factors involved in cell survival, but thermal resistance is not related to homeoviscous adaptation of the plasma membrane. These results have implications for growth and regrowth of populations experiencing environmental heat stress and our understanding of impacts at the level of the single cell. Given the important role of microbes in biofuel production and bioremediation, a thorough understanding of the impact of stress responses of populations and individuals is highly desirable

Temporal Development of Scour Holes around Submerged Stream Deflectors

Although the deflector structures used in many fish habitat rehabilitation schemes are frequently overtopped, few studies have examined the scour patterns created around submerged models. Furthermore, laboratory studies typically test smooth-surfaced structures, when those installed in natural rivers are generally made of logs or boulders. This study uses rough-surfaced, paired deflectors to investigate the temporal evolution of scour for three overtopping ratios in identical approach flow conditions in a flume. Results show that when maintaining identical discharge, raising deflector height and thus reducing the overtopping ratio (flow depth / structure height), an increased depth and volume of scour is generated next to the structures. The location of maximum depth and the rate of scouring with time is similar for the two highest deflectors (overtopping ratios of 1.22 and 1.83), but different for the lowest deflector model (overtopping ratio of 3.67). In order to improve the success rate of river restoration projects using in-stream structures, the overtopping ratio should be used in equations that predict scour depth evolution with time

Microsatellite Markers Confirm Self‐Pollination and Autogamy in Wild Populations of Vanilla mexicana Mill. (syn. V. inodora) (Orchidaceae) in the Island of Guadeloupe

The study aimed at evaluating the mating system of Vanilla mexicana (Orchidaceae) in natural populations in the island of Guadeloupe. A total of 132 V. mexicana samples were collected from 12 sites in Guadeloupe (Basse‐Terre). Five other samples coming from Martinique and Mexico completed our analyses. Reproductive biology experiments excluding pollinators with bagged flowers revealed 53.9% fruit set, a value identical to the natural fruit set measured in the populations. These results suggested that V. mexicana, unlike most Vanilla species, was reproducing by self‐pollination and autogamy. Due to lack of specific DNA markers for V. mexicana, microsatellite markers, previously developed in other Vanilla species, were used for the genetic analyses. Only 6 out of the 33 markers tested were transferable and polymorphic in V. mexicana. A panel of 51 V. mexicana samples genotyped with 3 polymorphic loci was finally retained for Guadeloupe population genetic analyses. A heterozygote deficiency was detected, and the selfing rate was estimated to 74%. These results confirmed the reproductive biology results as self‐pollination and autogamy were the most likely explanation for this deficit. Results were compared to those from allogamous wild Vanilla species and discussed in the light of suggested existence of a pollinator for V. mexicana in other areas (Mexico)

Surviving the heat:Heterogeneity of response in Saccharomyces cerevisiae provides insight into thermal damage to the membrane

International audienceEnvironmental heat stress impacts on the physiology and viability of microbial cells with concomitant implications for microbial activity and diversity. Previously, it has been demonstrated that gradual heating of Saccharomyces cerevisiae induces a degree of thermal resistance, whereas a heat shock results in a high level of cell death. Here, we show that the impact of exogenous nutrients on acquisition of thermal resistance differs between strains.Using single‐cell methods, we demonstrate the extent of heterogeneity of the heat‐stress response within populations of yeast cells and the presence of subpopulations that are reversibly damaged by heat stress. Such cells represent potential for recovery of entire populations once stresses are removed. The results show that plasma membrane permeability and potential are key factors involved in cell survival, but thermal resistance is not related to homeoviscous adaptation of the plasma membrane. These results have implications for growth and regrowth of populations experiencing environmental heat stress and our understanding of impacts at the level of the single cell. Given the important role of microbes in biofuel production and bioremediation, a thorough understanding of the impact of stress responses of populations and individuals is highly desirable

A Randomized Clinical Trial of Cognitive-Behavioral Therapy and Applied Relaxation for Adults With Generalized Anxiety Disorder

This randomized clinical trial compared cognitive-behavioral therapy (CBT), applied relaxation (AR) and wait-list control (WL) in a sample of 65 adults with a primary diagnosis of generalized anxiety disorder (GAD). The CBT condition was based on the intolerance of uncertainty model of GAD, whereas the AR condition was based on general theories of anxiety. Both manualized treatments were administered over 12 weekly one-hour sessions. Standardized clinician ratings and self-report questionnaires were used to assess GAD and related symptoms at pretest, posttest, and at 6-, 12- and 24-month follow-ups. At posttest, CBT was clearly superior to WL, AR was marginally superior to WL, and CBT was marginally superior to AR. Over follow-up, CBT and AR were equivalent, but only CBT led to continued improvement. Thus, direct comparisons of CBT and AR indicated that the treatments were comparable; however, comparisons of each treatment with another point of reference (either waiting list or no change over follow-up) provided greater support for the efficacy of CBT than AR

Structural and functional characterization of interactions involving the Tfb1 subunit of TFIIH and the NER factor Rad2

The general transcription factor IIH (TFIIH) plays crucial roles in transcription as part of the pre-initiation complex (PIC) and in DNA repair as part of the nucleotide excision repair (NER) machinery. During NER, TFIIH recruits the 3′-endonuclease Rad2 to damaged DNA. In this manuscript, we functionally and structurally characterized the interaction between the Tfb1 subunit of TFIIH and Rad2. We show that deletion of either the PH domain of Tfb1 (Tfb1PH) or several segments of the Rad2 spacer region yield yeast with enhanced sensitivity to UV irradiation. Isothermal titration calorimetry studies demonstrate that two acidic segments of the Rad2 spacer bind to Tfb1PH with nanomolar affinity. Structure determination of a Rad2–Tfb1PH complex indicates that Rad2 binds to TFIIH using a similar motif as TFIIEα uses to bind TFIIH in the PIC. Together, these results provide a mechanistic bridge between the role of TFIIH in transcription and DNA repair

Phenotype Frequencies of Autosomal Minor Histocompatibility Antigens Display Significant Differences among Populations

Minor histocompatibility (H) antigens are allogeneic target molecules having significant roles in alloimmune responses after human leukocyte antigen–matched solid organ and stem cell transplantation (SCT). Minor H antigens are instrumental in the processes of transplant rejection, graft-versus-host disease, and in the curative graft-versus-tumor effect of SCT. The latter characteristic enabled the current application of selected minor H antigens in clinical immunotherapeutic SCT protocols. No information exists on the global phenotypic distribution of the currently identified minor H antigens. Therefore, an estimation of their overall impact in human leukocyte antigen–matched solid organ and SCT in the major ethnic populations is still lacking. For the first time, a worldwide phenotype frequency analysis of ten autosomal minor H antigens was executed by 31 laboratories and comprised 2,685 randomly selected individuals from six major ethnic populations. Significant differences in minor H antigen frequencies were observed between the ethnic populations, some of which appeared to be geographically correlated

Autoantibodies neutralizing type I IFNs are present in ~4% of uninfected individuals over 70 years old and account for ~20% of COVID-19 deaths

Publisher Copyright: © 2021 The Authors, some rights reserved.Circulating autoantibodies (auto-Abs) neutralizing high concentrations (10 ng/ml; in plasma diluted 1:10) of IFN-alpha and/or IFN-omega are found in about 10% of patients with critical COVID-19 (coronavirus disease 2019) pneumonia but not in individuals with asymptomatic infections. We detect auto-Abs neutralizing 100-fold lower, more physiological, concentrations of IFN-alpha and/or IFN-omega (100 pg/ml; in 1:10 dilutions of plasma) in 13.6% of 3595 patients with critical COVID-19, including 21% of 374 patients >80 years, and 6.5% of 522 patients with severe COVID-19. These antibodies are also detected in 18% of the 1124 deceased patients (aged 20 days to 99 years; mean: 70 years). Moreover, another 1.3% of patients with critical COVID-19 and 0.9% of the deceased patients have auto-Abs neutralizing high concentrations of IFN-beta. We also show, in a sample of 34,159 uninfected individuals from the general population, that auto-Abs neutralizing high concentrations of IFN-alpha and/or IFN-omega are present in 0.18% of individuals between 18 and 69 years, 1.1% between 70 and 79 years, and 3.4% >80 years. Moreover, the proportion of individuals carrying auto-Abs neutralizing lower concentrations is greater in a subsample of 10,778 uninfected individuals: 1% of individuals 80 years. By contrast, auto-Abs neutralizing IFN-beta do not become more frequent with age. Auto-Abs neutralizing type I IFNs predate SARS-CoV-2 infection and sharply increase in prevalence after the age of 70 years. They account for about 20% of both critical COVID-19 cases in the over 80s and total fatal COVID-19 cases.Peer reviewe

Autoantibodies against type I IFNs in patients with critical influenza pneumonia

In an international cohort of 279 patients with hypoxemic influenza pneumonia, we identified 13 patients (4.6%) with autoantibodies neutralizing IFN-alpha and/or -omega, which were previously reported to underlie 15% cases of life-threatening COVID-19 pneumonia and one third of severe adverse reactions to live-attenuated yellow fever vaccine. Autoantibodies neutralizing type I interferons (IFNs) can underlie critical COVID-19 pneumonia and yellow fever vaccine disease. We report here on 13 patients harboring autoantibodies neutralizing IFN-alpha 2 alone (five patients) or with IFN-omega (eight patients) from a cohort of 279 patients (4.7%) aged 6-73 yr with critical influenza pneumonia. Nine and four patients had antibodies neutralizing high and low concentrations, respectively, of IFN-alpha 2, and six and two patients had antibodies neutralizing high and low concentrations, respectively, of IFN-omega. The patients' autoantibodies increased influenza A virus replication in both A549 cells and reconstituted human airway epithelia. The prevalence of these antibodies was significantly higher than that in the general population for patients 70 yr of age (3.1 vs. 4.4%, P = 0.68). The risk of critical influenza was highest in patients with antibodies neutralizing high concentrations of both IFN-alpha 2 and IFN-omega (OR = 11.7, P = 1.3 x 10(-5)), especially those <70 yr old (OR = 139.9, P = 3.1 x 10(-10)). We also identified 10 patients in additional influenza patient cohorts. Autoantibodies neutralizing type I IFNs account for similar to 5% of cases of life-threatening influenza pneumonia in patients <70 yr old

The risk of COVID-19 death is much greater and age dependent with type I IFN autoantibodies

SignificanceThere is growing evidence that preexisting autoantibodies neutralizing type I interferons (IFNs) are strong determinants of life-threatening COVID-19 pneumonia. It is important to estimate their quantitative impact on COVID-19 mortality upon SARS-CoV-2 infection, by age and sex, as both the prevalence of these autoantibodies and the risk of COVID-19 death increase with age and are higher in men. Using an unvaccinated sample of 1,261 deceased patients and 34,159 individuals from the general population, we found that autoantibodies against type I IFNs strongly increased the SARS-CoV-2 infection fatality rate at all ages, in both men and women. Autoantibodies against type I IFNs are strong and common predictors of life-threatening COVID-19. Testing for these autoantibodies should be considered in the general population