Delaneyfenger8224

Adaptation of cell populations to environmental changes is mediated by phenotypic variability at the single-cell level. Enzyme activity is a key factor in cell phenotype and the expression of the alkaline phosphatase activity (APA) is a fundamental phytoplankton strategy for maintaining growth under phosphate-limited conditions. Our aim was to compare the APA among cells and species revived from sediments of the Bay of Brest (Brittany, France), corresponding to a pre-eutrophication period (1940's) and a beginning of a post-eutrophication period (1990's) during which phosphate concentrations have undergone substantial variations. Both toxic marine dinoflagellate Alexandrium minutum and the non-toxic dinoflagellate Scrippsiella acuminata were revived from ancient sediments. Using microfluidics, we measured the kinetics of APA at the single-cell level. Our results indicate that all S. acuminata strains had significantly higher APA than A. minutum strains. For both species, the APA in the 1990's decade was significantly lower than in the 1940's. For the first time, our results reveal both inter and intraspecific variabilities of dinoflagellate APA and suggest that, at a half-century timescale, two different species of dinoflagellate may have undergone similar adaptative evolution to face environmental changes and acquire ecological advantages.Semen is important in determining HIV-1 susceptibility but it is unclear how it affects virus transmission during sexual contact. Mucosal Langerhans cells (LCs) are the first immune cells to encounter HIV-1 during sexual contact and have a barrier function as LCs are restrictive to HIV-1. As semen from people living with HIV-1 contains complement-opsonized HIV-1, we investigated the effect of complement on HIV-1 dissemination by human LCs in vitro and ex vivo. Notably, pre-treatment of HIV-1 with semen enhanced LC infection compared to untreated HIV-1 in the ex vivo explant model. Infection of LCs and transmission to target cells by opsonized HIV-1 was efficiently inhibited by blocking complement receptors CR3 and CR4. Complement opsonization of HIV-1 enhanced uptake, fusion, and integration by LCs leading to an increased transmission of HIV-1 to target cells. However, in the absence of both CR3 and CR4, C-type lectin receptor langerin was able to restrict infection of complement-opsonized HIV-1. These data suggest that complement enhances HIV-1 infection of LCs by binding CR3 and CR4, thereby bypassing langerin and changing the restrictive nature of LCs into virus-disseminating cells. Targeting complement factors might be effective in preventing HIV-1 transmission.Inflammatory bowel disease is characterized by an exacerbated intestinal immune response, but the critical mechanisms regulating immune activation remain incompletely understood. We previously reported that the TNF-superfamily molecule TNFSF14 (LIGHT) is required for preventing severe disease in mouse models of colitis. In addition, deletion of lymphotoxin beta receptor (LTβR), which binds LIGHT, also led to aggravated colitis pathogenesis. Here, we aimed to determine the cell type(s) requiring LTβR and the mechanism critical for exacerbation of colitis. Specific deletion of LTβR in neutrophils (LTβRΔN), but not in several other cell types, was sufficient to induce aggravated colitis and colonic neutrophil accumulation. Mechanistically, RNA-Seq analysis revealed LIGHT-induced suppression of cellular metabolism, and mitochondrial function, that was dependent on LTβR. Functional studies confirmed increased mitochondrial mass and activity, associated with excessive mitochondrial ROS production and elevated glycolysis at steady-state and during colitis. Targeting these metabolic changes rescued exacerbated disease severity. Our results demonstrate that LIGHT signals to LTβR on neutrophils to suppress metabolic activation and thereby prevents exacerbated immune pathogenesis during colitis.IgA mediates microbial homeostasis at the intestinal mucosa. Within the gut, IgA acts in a context-dependent manner to both prevent and promote bacterial colonization and to influence bacterial gene expression, thus providing exquisite control of the microbiota. IgA-microbiota interactions are highly diverse across individuals and populations, yet the factors driving this variation remain poorly understood. In this Review, we summarize evidence for the host, bacterial and environmental factors that influence IgA-microbiota interactions. GNE-317 nmr Recent advances have helped to clarify the antigenic specificity and immune selection of intestinal IgA and have highlighted the importance of microbial glycan recognition. Furthermore, emerging evidence suggests that diet and nutrition play an important role in shaping IgA recognition of the microbiota. IgA-microbiota interactions are disrupted during both overnutrition and undernutrition and may be altered dynamically in response to diet, with potential implications for host health. We situate this research in the context of outstanding questions and future directions in order to better understand the fascinating paradigm of IgA-microbiota homeostasis.Considered that human activities mostly occur below building heights, the objective of this study was to investigate the temporal variations of fine particular matter (PM2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and benzo[a]pyrene-equivalent (BaPeq) concentrations at four different elevations (6.1, 12.4, 18.4, and 27.1 m) in Kaohsiung City, the largest industrial city of southern Taiwan. Temperature variation was critical for the PM2.5-associated PAH concentrations, which were dominated by benzo[g,h,i]perylene (0.27 ± 0.04 ng m-3 and 24.43% of the total concentration) and other high molecular weight (HMW) species. The PM2.5-associated BaPeq was dominated by 5-ring PAH (36.09%). The PM2.5-associated PAH and BaPeq concentrations at all elevations were significantly increased in winter. In the night, the correlations between the PM2.5-associated PAH concentrations and atmospheric temperatures became negatively stronger, notably at lower elevations (r = - 0.73 ~ - 0.86), whereas the BaPeq during daytime and nighttime were not changed significantly in most months.