biostudies-literatureUnknownRamseier NTTetraspanin proteins are closely associated with high-curvature membrane structures and play key roles in organizing membrane domains and regulating membrane signaling in immune cells. However, their specific roles in regulating T cell membrane signaling, particularly within the microvilli often characteristic of these cells, remain poorly understood. Here, we used Jurkat T cells as a model system and investigated CD81 as a member of the tetraspanin family. Using total internal reflection fluorescence (TIRF) microscopy and structured illumination microscopy (SIM), we identified an enrichment of the tetraspanin CD81 microdomains along the actin-rich membrane microvilli. At the distal end of the microvilli, SIM images revealed the spatial colocalization of CD81 with T cell receptors (TCR) anbioRxiv : the preprint server for biology2024.12.07.627345https://www.ebi.ac.uk/biostudies/studies/S-EPMC11643289biostudies-literatureSuperresolution Imaging Reveals the Spatial Organization of CD81 Microdomains in Regulating Membrane Signaling on Jurkat T Cell Microvilli.PMC11643289Jing HAnderson JHu YSRamseier NTfalseSuperresolution Imaging Reveals the Spatial Organization of CD81 Microdomains in Regulating Membrane Signaling on Jurkat T Cell Microvilli.Tetraspanin proteins are closely associated with high-curvature membrane structures and play key roles in organizing membrane domains and regulating membrane signaling in immune cells. However, their specific roles in regulating T cell membrane signaling, particularly within the microvilli often characteristic of these cells, remain poorly understood. Here, we used Jurkat T cells as a model system and investigated CD81 as a member of the tetraspanin family. Using total internal reflection fluorescence (TIRF) microscopy and structured illumination microscopy (SIM), we identified an enrichment of the tetraspanin CD81 microdomains along the actin-rich membrane microvilli. At the distal end of the microvilli, SIM images revealed the spatial colocalization of CD81 with T cell receptors (TCR) an2024-01-01T00:00:00Z2024 Dec2025-04-05T09:51:41.553Z2025-04-05T09:51:41.553ZS-EPMC116432893967777110.1101/2024.12.07.627345