A closer look at CD1d molecules: new horizons in studying NKT cells.

Recent findings have highlighted the ability of invariant natural killer T (iNKT) cells to recognize microbe-derived glycolipids and have demonstrated the role of these cells in several disease states, from autoimmune disease to cancer. It has also become clear that iNKT cells can rapidly mature dendritic cells and licence them to prime antigen-specific T- and B-cell responses. The use of CD1d tetramers to monitor iNKT cell frequency and phenotype has moved the field forward at a fast pace. To harness iNKT cells for therapeutic purposes and to understand their role in vivo, it is essential to characterize the molecular events that contribute to iNKT cell activation. Here we review new reagents and novel protocols that are facilitating a closer look at lipid presentation by CD1d molecules and their recognition by iNKT cells

Impactos ambientales de la huella hídrica y la generación de residuos de alimentos utilizados en las comidas de los trabajadores de un hospital público brasileño

This study aimed to assess the environmental impacts of waste generation and the WF of raw materials used to provide meals to workers in a public hospital in southern Brazil over the course of the four seasons. This is a descriptive case study with a quant itative approach. The food raw materials that composed meals during 2019 were grouped by type of input. The items included from each food group were those which represented at least 85% (Multiple Criteria ABC Analysis) of the total amount used in kilograms within the respective group, in each month. The generation of residues from fruits, vegetables, and meat was estimated, as well as the WF of the items. For the statistical analysis, the Kruskal - Wallis test was used with a significance of 5%. Out of the 96 food inputs used, 49 items represented 86% of the total in kg, being the ones from which the environmental impacts were calculated. During the year, 435,411 meals were served. As for the number of diners, the highest frequency was observed in the winter a nd lowest in the summer. The annual waste percentage of the fruits acquired was 33.8%, being higher in the summer than in other seasons. Animal products were responsible for 64.2% of the WF, being higher in the winter. Assessing user frequencies, climatic conditions, and raw - material selection are important measures for the appropriate management of foodservices, as well as for assessing their environmental impacts.Este estudo teve como objetivo avaliar os impactos ambientais da geração de resíduos e da pegada hídrica (PH) das matérias - primas utilizadas na alimentação dos trabalhadores de um hospital público do sul do Brasil ao longo das quatro estações. Trata - se de um estudo de caso descritivo com abordagem quantitativa. As matérias - primas alimentares que compunham as refeições durante 2019 foram agrupadas por tipo de insumo. Os itens incluídos de cada grupo de alimentos foram aqueles que representaram pelo menos 85% (Análise Curva ABC) da quantidade total utilizada em quilogramas (kg) dentro do respectivo grupo, em cada mês. Foi estimada a geração de resíduos de frutas, hortaliças e carnes, bem como a PH dos itens. Para a análise estatística, foi utilizado o teste de Kruskal - Wallis com significância de 5%. Dos 96 insumos alimentares utilizados, 49 itens representaram 86% do total em kg, sendo aqueles a partir dos quais foram calculados os impactos ambientais. No ano, foram servidas 435.411 refeições. Quanto ao número de comensais, a maior frequência foi observada no inverno e a menor no verão. As frutas tiveram um total de 33,8% de desperdício, sendo que no verão foi observado a maior quantidade. Os produtos de origem animal foram responsáveis por 64,2% da PH, e no i nverno foi identificado os maiores valores. A avaliação das frequências dos usuários, as condições climáticas e a seleção de matérias - primas são medidas importantes para o gerenciamento adequado dos serviços de alimentação, bem como para avaliar seus impactos ambientais.Este estudio tuvo como objetivo evaluar los impactos ambientales de la generación de residuos y el huela hídrica (HH) de las materias primas utilizadas par a proporcionar alimentos a los trabajadores de un hospital público en el sur de Brasil durante las cuatro estaciones Del año. Este es un estudio de caso descriptivo con un enfoque cuantitativo. Las materias primas alimentarias que componían las comidas dur ante 2019 se agruparon por tipo de insumo. Los ítems incluidos de cada grupo de alimentos fueron aquellos que representaron al menos el 85% (Análisis ABC) de la cantidad total utilizada en kilogramos (kg) dentro del grupo respectivo, en cada mes. Se estimó la generación de residuos de frutas, verduras y carnes, así como la HH de los artículos. Para el análisis estadístico se utilizó la prueba de Kruskal - Wallis con una significancia del 5%. De los 96 insumos alimentarios utilizados, 49 ítems representaron el 86% del total en kg, siendo a partir de los cuales se calcularon los impactos ambientales. Durante el año se sirvieron 435,411 comidas. En cuanto al número de comensales, la mayor frecuencia se observó en invierno y la menor en verano. El porcentaje de de sperdicio anual de los frutos adquiridos fue del 33,8%, siendo mayor en verano que en otras temporadas. Los productos animales fueron responsables del 64,2% de la HH, siendo mayor en invierno. La evaluación de la frecuencia de los usuarios, las condiciones climáticas y la selección de materias primas son medidas importantes para la gestión adecuada de los servicios alimentarios, así como para evaluar sus impactos ambientale

The length of lipids bound to human CD1d molecules modulates the affinity of NKT cell TCR and the threshold of NKT cell activation.

CD1d-restricted lymphocytes recognize a broad lipid range. However, how CD1d-restricted lymphocytes translate T cell receptor (TCR) recognition of lipids with similar group heads into distinct biological responses remains unclear. Using a soluble invariant NKT (iNKT) TCR and a newly engineered antibody specific for alpha-galactosylceramide (alpha-GalCer)-human CD1d (hCD1d) complexes, we measured the affinity of binding of iNKT TCR to hCD1d molecules loaded with a panel of alpha-GalCer analogues and assessed the rate of dissociation of alpha-GalCer and alpha-GalCer analogues from hCD1d molecules. We extended this analysis by studying iNKT cell synapse formation and iNKT cell activation by the same panel of alpha-GalCer analogues. Our results indicate the unique role of the lipid chain occupying the hCD1d F' channel in modulating TCR binding affinity to hCD1d-lipid complexes, the formation of stable immunological synapse, and cell activation. These data are consistent with previously described conformational changes between empty and loaded hCD1d molecules (Koch, M., V.S. Stronge, D. Shepherd, S.D. Gadola, B. Mathew, G. Ritter, A.R. Fersht, G.S. Besra, R.R. Schmidt, E.Y. Jones, and V. Cerundolo. 2005. Nat. Immunol 6:819-826), suggesting that incomplete occupation of the hCD1d F' channel results in conformational differences at the TCR recognition surface. This indirect effect provides a general mechanism by which lipid-specific lymphocytes are capable of recognizing both the group head and the length of lipid antigens, ensuring greater specificity of antigen recognition