2026-04-17T14:16:29Zhttps://recercat.cat/oai/request

oai:recercat.cat:10230/700002025-12-12T02:34:46Zcom_2072_6col_2072_452952

00925njm 22002777a 4500 dc Cebrian Lazart, Ignacio author Dinamarca, Sofía author Pena Rodriguez, Maria author Priego, Elena author Brouwers, Nathalie author Barends, Martina author Brunnberg, Jamina author Tampé, Robert author Blanchard, Nicolas author Sancho, David author Malhotra, Vivek author 2025-03-25T07:24:50Z 2025-03-25T07:24:50Z 2025 Dendritic cells (DCs) present exogenous antigens via major histocompatibility complex class I (MHC-I) and MHC class II (MHC-II) molecules, activating CD8+ and CD4+ T cells. A critical but poorly understood step in this process is the trafficking of peptide-loaded MHC molecules from the endocytic system to the cell surface. In this study, we demonstrate that the Golgi reassembly-stacking protein of 55 kDa (GRASP55), which has been shown to have no role in stacking, is essential for antigen presentation. Using soluble, bead-coated, and bacterial-bound antigens, we found significantly impaired exogenous antigen presentation in GRASP55-deficient bone-marrow-derived DCs (BMDCs). Notably, GRASP55 was recruited to late phagosomes, and our data suggest that it is crucial for sorting MHC-I and MHC-II molecules, facilitating their trafficking to the plasma membrane. Our findings highlight the vital role of GRASP55 in the intracellular transport of MHC molecules bound to their respective peptides during exogenous antigen presentation. CP: Immunology GRASP55 MHC transport Antigen presentation Dendritic cells Phagosomes Dendritic cell phagosomes recruit GRASP55 for export of antigen-loaded MHC molecules