Islet lymphocyte subsets in male and female NOD mice are qualitatively similar but quantitatively distinct

Islet-infiltrating lymphocytes of individual male and female non-obese diabetic (NOD) mice were examined with the purpose of determining the differences that lead to a predominance of diabetes in female versus males NOD mice. When normalized for the amount of islet lymphocytes recovered, the infiltrating lymphocytes of female NOD mice were indistinguishable from those of male NOD mice. The only observed difference was that islet inflammation progressed at an increased rate in female compared to male NOD mice. There was no difference in the composition of islet infiltrates in male and female NOD mice. Unexpectedly, the ratio of CD4+:CD8+ T cells was tightly controlled in the islets throughout diabetogenesis. The frequency of IL-4+ CD4+ T cells started high but quickly fell to 3% of the population which was maintained with increasing inflammation. A significant portion of the CD8+ T cells were islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) specific in both male and female NOD mice and this population was antigen experienced and increased at high levels of islet inflammation. Surprisingly, a large pool of antigen inexperienced naïve T cells was detected in the islets. We conclude the underlying immunological processes in both male and female NOD mice are similar while the rates differ and the presence of naïve T cell in the islets may contribute to epitope spreading

Foodways in transition: food plants, diet and local perceptions of change in a Costa Rican Ngäbe community

Background Indigenous populations are undergoing rapid ethnobiological, nutritional and socioeconomic transitions while being increasingly integrated into modernizing societies. To better understand the dynamics of these transitions, this article aims to characterize the cultural domain of food plants and analyze its relation with current day diets, and the local perceptions of changes given amongst the Ngäbe people of Southern Conte-Burica, Costa Rica, as production of food plants by its residents is hypothesized to be drastically in recession with an decreased local production in the area and new conservation and development paradigms being implemented. Methods Extensive freelisting, interviews and workshops were used to collect the data from 72 participants on their knowledge of food plants, their current dietary practices and their perceptions of change in local foodways, while cultural domain analysis, descriptive statistical analyses and development of fundamental explanatory themes were employed to analyze the data. Results Results show a food plants domain composed of 140 species, of which 85 % grow in the area, with a medium level of cultural consensus, and some age-based variation. Although many plants still grow in the area, in many key species a decrease on local production–even abandonment–was found, with much reduced cultivation areas. Yet, the domain appears to be largely theoretical, with little evidence of use; and the diet today is predominantly dependent on foods bought from the store (more than 50 % of basic ingredients), many of which were not salient or not even recognized as ‘food plants’ in freelists exercises. While changes in the importance of food plants were largely deemed a result of changes in cultural preferences for store bought processed food stuffs and changing values associated with farming and being food self-sufficient, Ngäbe were also aware of how changing household livelihood activities, and the subsequent loss of knowledge and use of food plants, were in fact being driven by changes in social and political policies, despite increases in forest cover and biodiversity. Conclusions Ngäbe foodways are changing in different and somewhat disconnected ways: knowledge of food plants is varied, reflecting most relevant changes in dietary practices such as lower cultivation areas and greater dependence on food from stores by all families. We attribute dietary shifts to socioeconomic and political changes in recent decades, in particular to a reduction of local production of food, new economic structures and agents related to the State and globalization

Toxin-Coupled MHC Class I Tetramers Can Specifically Ablate Autoreactive CD8+ T Cells and Delay Diabetes in Nonobese Diabetic Mice

There is compelling evidence that self reactive CD8+ T cells are a major factor in development and progression of Type 1 diabetes in animals and humans. Hence, great effort has been expended to define the specificity of autoimmune CD8+ T cells, and to alter their responses. Much work has focused on tolerization of T cells using proteins or peptides. A weakness in this approach is residual autoreactive T cells may be activated and exacerbate disease

Lineage Regulators Direct BMP and Wnt Pathways to Cell-Specific Programs during Differentiation and Regeneration

SummaryBMP and Wnt signaling pathways control essential cellular responses through activation of the transcription factors SMAD (BMP) and TCF (Wnt). Here, we show that regeneration of hematopoietic lineages following acute injury depends on the activation of each of these signaling pathways to induce expression of key blood genes. Both SMAD1 and TCF7L2 co-occupy sites with master regulators adjacent to hematopoietic genes. In addition, both SMAD1 and TCF7L2 follow the binding of the predominant lineage regulator during differentiation from multipotent hematopoietic progenitor cells to erythroid cells. Furthermore, induction of the myeloid lineage regulator C/EBPα in erythroid cells shifts binding of SMAD1 to sites newly occupied by C/EBPα, whereas expression of the erythroid regulator GATA1 directs SMAD1 loss on nonerythroid targets. We conclude that the regenerative response mediated by BMP and Wnt signaling pathways is coupled with the lineage master regulators to control the gene programs defining cellular identity

Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Filtration Improves the Performance of a High-Throughput Screen for Anti-Mycobacterial Compounds

The tendency for mycobacteria to aggregate poses a challenge for their use in microplate based assays. Good dispersions have been difficult to achieve in high-throughput screening (HTS) assays used in the search for novel antibacterial drugs to treat tuberculosis and other related diseases. Here we describe a method using filtration to overcome the problem of variability resulting from aggregation of mycobacteria. This method consistently yielded higher reproducibility and lower variability than conventional methods, such as settling under gravity and vortexing

Protein-coding variants implicate novel genes related to lipid homeostasis contributing to body-fat distribution.

Body-fat distribution is a risk factor for adverse cardiovascular health consequences. We analyzed the association of body-fat distribution, assessed by waist-to-hip ratio adjusted for body mass index, with 228,985 predicted coding and splice site variants available on exome arrays in up to 344,369 individuals from five major ancestries (discovery) and 132,177 European-ancestry individuals (validation). We identified 15 common (minor allele frequency, MAF ≥5%) and nine low-frequency or rare (MAF <5%) coding novel variants. Pathway/gene set enrichment analyses identified lipid particle, adiponectin, abnormal white adipose tissue physiology and bone development and morphology as important contributors to fat distribution, while cross-trait associations highlight cardiometabolic traits. In functional follow-up analyses, specifically in Drosophila RNAi-knockdowns, we observed a significant increase in the total body triglyceride levels for two genes (DNAH10 and PLXND1). We implicate novel genes in fat distribution, stressing the importance of interrogating low-frequency and protein-coding variants