Examinando por Autor "Feijoo, Carmen G."
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Ítem Antigen-Presenting Cells and T Cells Interact in a Specific Area of the Intestinal Mucosa Defined by the Ccl25-Ccr9 Axis in Medaka(Frontiers Media S.A., 2022-02) Aghaallaei, Narges; Agarwal, Rashi; Benjaminsen, Joergen; Lust, Katharina; Bajoghli, Baubak; Wittbrodt, Joachim; Feijoo, Carmen G.Organized intestinal mucosal immune response appears to be restricted to tetrapods. In teleost fish, there is no evidence for the existence of a particular intestinal region that facilitates the interaction of antigen-presenting cells (APCs) and T cells, such as secondary lymphoid organs. Indeed, despite their importance in the defense against pathogens, the location and manner of APC-T cell interaction within the fish gut is unknown. Here, using non-invasive live imaging of newly developed transgenic reporter lines, we addressed the spatial organization and behavior of APCs and T cells in the intestine of medaka fish both during homeostasis and inflammation. We report that Ccr9a+ T cells are recruited to a band in the lamina propria next to the muscularis mucosa in which Ccl25-expressing cells are present. Ccr9a+ T cells contact APCs for several minutes, in a process mediated by connexin 43. This type of interaction was observed in homeostasis and inflammation, with the interaction being longer and more frequent during inflammation. Thus, our results demonstrate that the mucosal immune response in the intestine of medaka is organized and endowed with a specific region with specialized microenvironment and function. Copyright © 2022 Aghaallaei, Agarwal, Benjaminsen, Lust, Bajoghli, Wittbrodt and Feijoo.Ítem Ontogenetically distinct neutrophils differ in function and transcriptional profile in zebrafish(Nature Research, 2023-12) García-López, Juan P.; Grimaldi, Alexandre; Chen, Zelin; Meneses, Claudio; Bravo-Tello, Karina; Bresciani, Erica; Banderas, Alvaro; Burgess, Shawn M.; Hernández, Pedro P.; Feijoo, Carmen G.The current view of hematopoiesis considers leukocytes on a continuum with distinct developmental origins, and which exert non-overlapping functions. However, there is less known about the function and phenotype of ontogenetically distinct neutrophil populations. In this work, using a photoconvertible transgenic zebrafish line; Tg(mpx:Dendra2), we selectively label rostral blood island-derived and caudal hematopoietic tissue-derived neutrophils in vivo during steady state or upon injury. By comparing the migratory properties and single-cell expression profiles of both neutrophil populations at steady state we show that rostral neutrophils show higher csf3b expression and migration capacity than caudal neutrophils. Upon injury, both populations share a core transcriptional profile as well as subset-specific transcriptional signatures. Accordingly, both rostral and caudal neutrophils are recruited to the wound independently of their distance to the injury. While rostral neutrophils respond uniformly, caudal neutrophils respond heterogeneously. Collectively, our results reveal that co-existing neutrophils populations with ontogenically distinct origin display functional differences.Ítem SNX5 promotes antigen presentation in B cells by dual regulation of actin and lysosomal dynamics(Life Science Alliance, LLC, 0025-01) Cabrera-Reyes, Fernanda; Contreras-Palacios, Teemly; Jara-Wilde, Jorge; Caballero, Mia; Quiroga, Clara; Feijoo, Carmen G.; Díaz-Muñoz, Jheimmy; Yuseff, María-IsabelB cells rapidly adapt their endocytic pathway to promote the uptake and processing of extracellular antigens recognized through the B-cell receptor (BCR). The mechanisms coupling changes in endomembrane trafficking to the capacity of B cells to screen for antigens within lymphoid tissues remain unaddressed. We investigated the role of SNX5, a member of the sorting nexin family, which interacts with endocytic membranes to regulate vesicular trafficking and macropinocytosis. Our results show that in steady state, B cells form SNX5-rich protrusions at the plasma membrane, which dissipate upon interaction with soluble antigens, whereas B cells activated with immobilized antigens accumulate SNX5 at the immune synapse where it regulates actin-dependent spreading responses. B cells silenced for SNX5 exhibit enlarged lysosomes, which are not recruited to the synaptic membrane, decreasing their capacity to extract immobilized antigens. Overall, our findings reveal that SNX5 is critical for actin-dependent plasma membrane remodeling in B cells in-volved in antigen screening and immune synapse formation, as well as endolysosomal trafficking required to promote antigen extraction and presentation. © 2024 Cabrera-Reyes et al.Ítem SNX5 promotes antigen presentation in B cells by dual regulation of actin and lysosomal dynamics(Life Science Alliance, Volume 8, Issue 1January 2025 Article number e202402917, 2025) Cabrera-Reyes, Fernanda; Contreras-Palacios, Teemly; Ulloa, Romina; Jara-Wilde, Jorge; Caballero, Mia; Quiroga, Clara; Feijoo, Carmen G.; Díaz-Muñoz, Jheimmy; Yuseff, María-IsabelB cells rapidly adapt their endocytic pathway to promote the uptake and processing of extracellular antigens recognized through the B-cell receptor (BCR). The mechanisms coupling changes in endomembrane trafficking to the capacity of B cells to screen for antigens within lymphoid tissues remain unaddressed. We investigated the role of SNX5, a member of the sorting nexin family, which interacts with endocytic membranes to regulate vesicular trafficking and macropinocytosis. Our results show that in steady state, B cells form SNX5-rich protrusions at the plasma membrane, which dissipate upon interaction with soluble antigens, whereas B cells activated with immobilized antigens accumulate SNX5 at the immune synapse where it regulates actin-dependent spreading responses. B cells silenced for SNX5 exhibit enlarged lysosomes, which are not recruited to the synaptic membrane, decreasing their capacity to extract immobilized antigens. Overall, our findings reveal that SNX5 is critical for actin-dependent plasma membrane remodeling in B cells in-volved in antigen screening and immune synapse formation, as well as endolysosomal trafficking required to promote antigen extraction and presentation. © 2024 Cabrera-Reyes et al