Polarized release of TCR-enriched microvesicles at the T cell immunological synapse

The recognition events that mediate adaptive cellular immunity and regulate antibody responses depend on intercellular contacts between T cells and antigen presenting cells (APC)1. T cell signaling is initiated at these contacts when surface-expressed antigen receptors (TCR) recognize peptide fragments (antigens) of pathogens bound to Major Histocompatibility Complex molecules (pMHC) on APCs. This, along with engagement of adhesion receptors, leads to the formation of a specialized junction between T cells and APCs, known as the immunological synapse (IS)3, which mediates efficient delivery of effector molecules and intercellular signals across the synaptic cleft2. T cell recognition of pMHC and the adhesion ligand Intercellular Adhesion Molecule-1 (ICAM-1) on supported planar bilayers recapitulates the domain organization of the immunological synapse (IS)4–5, which is characterized by central accumulation of TCR5, adjacent to a secretory domain3, both surrounded by an adhesive ring4–5. Although accumulation of TCR at the IS center correlates with T cell function4, this domain is itself largely devoid of TCR signaling activity5–6, and is characterized by an unexplained immobilization of TCR-pMHC complexes relative to the highly dynamic IS periphery4–5. Here we show that centrally accumulated TCR is located on the surface of extracellular microvesicles that bud at the IS center. Tumor susceptibility gene 101 (TSG101)6 sorts TCR for inclusion in microvesicles, while vacuolar protein sorting 4 (VPS4) 7–8 mediates scission of microvesicles from the T cell plasma membrane. The HIV polyprotein GAG co-opts this process for budding of virus-like particles. B cells bearing cognate pMHC receive TCR from T cells and initiate intracellular signals in response to isolated synaptic microvesicles. We conclude that the immunological synapse orchestrates TCR sorting and release in extracellular microvesicles. These microvesicles deliver transcellular signals across antigen-dependent synapses by engaging cognate pMHC on APC

Seasonal sensory evaluation of low commercial value or unexploited fish species from the Portuguese coast

Overfishing is increasing over time, and according to FAO (Food and Agriculture Organization), about one third of the world’s fish stocks are now overfished. Thus, diversifying the target species is essential for fisheries sustainability contributing to improve resource-effcient processes. Non-target species can be valuable resources for the development of new food products. However, those species are scarcely studied, and it is of high importance to trace their seasonal sensory profile as a first step towards their valorisation. Therefore, in this study, seasonal influence on sensory properties of five low commercial value or unexploited fish species, namely Trachurus picturatus (blue jack mackerel), Spondyliosoma cantharus (black seabream), Trigla lyra (piper gurnard), Serranus cabrilla (comber) and Capros aper (boarfish), was assessed in order to identify the most favourable season for catching each species. Fish samples were assessed by a panel of 16 semi-trained assessors for sensory attributes previously identified. The evaluation takes place every 2 months. Statistical differences were reported between attributes and seasons for all species, except for T. lyra, which did not present any di erence in its sensory attributes throughout the year.info:eu-repo/semantics/publishedVersio

Self-reactive human CD4 T cell clones form unusual immunological synapses

Recognition of self–peptide-MHC (pMHC) complexes by CD4 T cells plays an important role in the pathogenesis of many autoimmune diseases. We analyzed formation of immunological synapses (IS) in self-reactive T cell clones from patients with multiple sclerosis and type 1 diabetes. All self-reactive T cells contained a large number of phosphorylated T cell receptor (TCR) microclusters, indicative of active TCR signaling. However, they showed little or no visible pMHC accumulation or transport of TCR–pMHC complexes into a central supramolecular activation cluster (cSMAC). In contrast, influenza-specific T cells accumulated large quantities of pMHC complexes in microclusters and a cSMAC, even when presented with 100-fold lower pMHC densities. The self-reactive T cells also maintained a high degree of motility, again in sharp contrast to virus-specific T cells. 2D affinity measurements of three of these self-reactive T cell clones demonstrated a normal off-rate but a slow on-rate of TCR binding to pMHC. These unusual IS features may facilitate escape from negative selection by self-reactive T cells encountering very small amounts of self-antigen in the thymus. However, these same features may enable acquisition of effector functions by self-reactive T cells encountering large amounts of self-antigen in the target organ of the autoimmune disease

Reproduction of the Blue Jack Mackerel, Trachurus picturatus, in Western Portugal: Microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns

This study was partially supported by the European Maritime and Fisheries Fund MAR2020 project “VALOREJET: Valorização de espécies rejeitadas e de baixo valor comercial”, MAR- 01.03.01-FEAMP-0003 and by Fundação para a Ciência e Tecnologia through research contracts attributed to Vera Sequeira (CEECIND/02705/2017) and Ana Rita Vieira (CEECIND/01528/2017) and strategic project UIBD/04292/2020.Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population off the west coast of Portugal. The proportion and length range of males and females were similar. Only three of the specimens collected were categorized as immature, indicating that the fish caught in the fishery are primarily mature. The spawning season lasted from late January until the end of March, with gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low number of females showing direct evidence of imminent or recent spawning suggests a low number of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning events. This study highlights the importance of accounting for skipped spawning events and ovary abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio

Modelling Fish Growth with Imperfect Data: The Case of Trachurus picturatus

Growth modelling is essential to inform fisheries management but is often hampered by sampling biases and imperfect data. Additional methods such as interpolating data through back-calculation may be used to account for sampling bias but are often complex and time-consuming. Here, we present an approach to improve plausibility in growth estimates when small individuals are under-sampled, based on Bayesian fitting growth models using Markov Chain Monte Carlo (MCMC) with informative priors on growth parameters. Focusing on the blue jack mackerel, Trachurus picturatus, which is an important commercial fish in the southern northeast Atlantic, this Bayesian approach was evaluated in relation to standard growth model fitting methods, using both direct readings and back-calculation data. Matched growth parameter estimates were obtained with the von Bertalanffy growth function applied to back-calculated length at age and the Bayesian fitting, using MCMC to direct age readings, with both outperforming all other methods assessed. These results indicate that Bayesian inference may be a powerful addition in growth modelling using imperfect data and should be considered further in age and growth studies, provided relevant biological information can be gathered and included in the analyses.info:eu-repo/semantics/publishedVersio

Adding value to bycatch fish species captured in the Portuguese coast—development of new food products

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.info:eu-repo/semantics/publishedVersio

Aumentar el conocimiento biológico para una mejor gestión de las especies de captura incidental: edad, crecimiento y mortalidad de garneo y arete (Teleostei: Triglidae)

Gurnards are a valuable by-catch of mixed demersal fisheries and are commercially important in European waters, but they are often discarded, reported under “mixed gurnards” and with incomplete biological information by species. In the present work, a total of 558 piper gurnard specimens of between 10.9 and 44.4 cm (1 to 11 years) and 425 red gurnard specimens of between 10.2 and 42.1 cm (0 to 9 years) from the northeast Atlantic (Portuguese) coast were used to study age and growth. The von Bertalanffy growth parameters for piper gurnard were estimated through the combination of whole-otolith readings and back-calculation (L∞=44.7 cm, k=0.16 yr–1 and t0=–2.781 yr). For red gurnard the same growth parameters were estimated using whole-otolith readings (L∞=40.2 cm, k=0.28 yr–1 and t0=–1.074 yr). The results indicate that the red gurnard reaches a smaller length, although it grows faster than the piper gurnard. Natural, instantaneous and fishing mortalities were estimated as well as the exploitation rate for both species. For the Portuguese coast, the red gurnard showed a higher fishing mortality and exploitation rate than the piper gurnard, raising concerns about its sustainable management.Los rubios son una captura incidental valiosa de las pesquerías demersales mixtas y comercialmente importantes en las aguas europeas, pero a menudo se descartan, se informan como “rubios mixtos” y con información biológica incompleta por especie. En el presente trabajo se han recogido un total de 558 ejemplares de ganeo, de entre 10,9 y 44,4 cm (1 a 11 años), y 425 individuos de arete, de entre 10,2 y 42,1 cm (0 a 9 años) procedentes del Atlántico nororiental (costa portuguesa) se utilizaron para estudiar la edad y el crecimiento. Los parámetros de crecimiento de von Bertalanffy para ganeo se estimaron mediante la combinación de lecturas de otolitos enteros y retrocálculo (L∞=44,7 cm, k=0,16 año–1 y t0=-2,781 años). Para el arete se estimaron los mismos parámetros de crecimiento usando lecturas de otolito entero (L∞=40.2 cm, k=0.28 año–1 y t0=–1.074 año). Los resultados indican que el arete alcanza una talla menor, aunque crece más rápido que el ganeo. Se estimó la mortalidad natural, instantánea y por pesca, así como la tasa de explotación para ambas especies. Para la costa portuguesa, el arete presentó una mortalidad por pesca y una tasa de explotación más altas que el ganeo, lo que generó preocupaciones sobre su gestión sostenible

Adding Value to Bycatch Fish Species Captured in the Portuguese Coast—Development of New Food Products

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.info:eu-repo/semantics/publishedVersio

Prevention of ventilator-associated pneumonia: the multimodal approach of the spanish ICU pneumonia zero program.

Objectives: The “Pneumonia Zero” project is a nationwide multimodal intervention based on the simultaneous implementation of a comprehensive evidence-based bundle measures to prevent ventilator-associated pneumonia in critically ill patients admitted to the ICU. Design: Prospective, interventional, and multicenter study. Setting: A total of 181 ICUs throughout Spain. Patients: All patients admitted for more than 24 hours to the participating ICUs between April 1, 2011, and December 31, 2012. Intervention: Ten ventilator-associated pneumonia prevention measures were implemented (seven were mandatory and three highly recommended). The database of the National ICU-Acquired Infections Surveillance Study (Estudio Nacional de Vigilancia de Infecciones Nosocomiales [ENVIN]) was used for data collection. Ventilator-associated pneumonia rate was expressed as incidence density per 1,000 ventilator days. Ventilator-associated pneumonia rates from the incorporation of the ICUs to the project, every 3 months, were compared with data of the ENVIN registry (April–June 2010) as the baseline period. Ventilator-associated pneumonia rates were adjusted by characteristics of the hospital, including size, type (public or private), and teaching (postgraduate) or university-affiliated (undergraduate) status. Measurements and Main Results: The 181 participating ICUs accounted for 75% of all ICUs in Spain. In a total of 171,237 ICU admissions, an artificial airway was present on 505,802 days (50.0% of days of stay in the ICU). A total of 3,474 ventilator-associated pneumonia episodes were diagnosed in 3,186 patients. The adjusted ventilator-associated pneumonia incidence density rate decreased from 9.83 (95% CI, 8.42–11.48) per 1,000 ventilator days in the baseline period to 4.34 (95% CI, 3.22–5.84) after 19–21 months of participation. Conclusions: Implementation of the bundle measures included in the “Pneumonia Zero” project resulted in a significant reduction of more than 50% of the incidence of ventilator-associated pneumonia in Spanish ICUs. This reduction was sustained 21 months after implementation

Functional single-cell analysis of T-cell activation by supported lipid bilayer-tethered ligands on arrays of nanowells

Supported lipid bilayers are an important biomolecular tool for characterizing immunological synapses. Immobilized bilayers presenting tethered ligands on planar substrates have yielded both spatio-temporal and structural insights into how T cell receptors (TCRs) reorganize during the initial formation of synapses upon recognition of peptide antigens bound to major histocompatibility complex (MHC) molecules. The prototypical configuration of these assays, however, limits the extent to which the kinetics and structure of the supramolecular activation clusters of the synapse (that occur in seconds or minutes) can be related to subsequent complex cellular responses, such as cytokine secretion and proliferation, occurring over hours to days. Here we describe a new method that allows correlative measures of both attributes with single-cell resolution by using immobilized lipid bilayers and tethered ligands on the surface of dense arrays of subnanoliter wells. This modification allows each nanowell to function as an artificial antigen-presenting cell (APC), and the synapses formed upon contact can be imaged by fluorescence microscopy. We show that the lipid bilayers remain stable and mobile on the surface of the PDMS, and that modifying the ligands tethered to the bilayer alters the structure of the resulting synapses in expected ways. Finally, we demonstrate that this approach allows the subsequent characterization of secreted cytokines from the activated human T cell clones by microengraving in both antigen- and pan-specific manners. This new technique should allow detailed investigations on how biophysical and structural aspects of the synapse influence the activation of individual T cells and their complex functional responses.National Institute of Allergy and Infectious Diseases (U.S.) (5P01AI045757)National Cancer Institute (U.S.) (Cancer Center Support (Core) Grant P30-CA14051