Unveiling the molecular architecture of T cells and immune synapses with cryo-expansion microscopy

Article Article scientifique Article Unveiling the molecular architecture of T cells and immune synapses with cryo-expansion microscopy eng 2026-04-01 author Lemaitre Florent Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. 404523 Département de biologie moléculaire et cellulaire (MOCEL) author Mercey Olivier Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. 943499 Département de biologie moléculaire et cellulaire (MOCEL) author Mean Isabelle Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. 682897 Département de biologie moléculaire et cellulaire (MOCEL) author Paulin Elise Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. 419094 author Dutoit Vallotton Valérie 0000-0002-3469-4237 Brain Tumor and Immune Cell Engineering Laboratory, Translational Research Centre in Onco-Hematology, Faculty of Medicine, University of Geneva, Geneva, Switzerland; Swiss Cancer Center Léman, Lausanne, Switzerland; Agora Cancer Research Center, Lausanne, Switzerland. 668630 Département de médecine (DEMED) author Rath Jan A Swiss Cancer Center Léman, Lausanne, Switzerland; Agora Cancer Research Center, Lausanne, Switzerland; Department of Oncology UNIL-CHUV, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland; Ludwig Institute for Cancer Research Lausanne Branch, Lausanne, Switzerland. author von Gunten Christine Department of Oncology UNIL-CHUV, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland; Ludwig Institute for Cancer Research Lausanne Branch, Lausanne, Switzerland. author Migliorini Denis Brain Tumor and Immune Cell Engineering Laboratory, Translational Research Centre in Onco-Hematology, Faculty of Medicine, University of Geneva, Geneva, Switzerland; Department of Oncology, University Hospital of Geneva, Geneva, Switzerland; Swiss Cancer Center Léman, Lausanne, Switzerland; Agora Cancer Research Center, Lausanne, Switzerland. 838158 Département de médecine (DEMED) author Arber Caroline Swiss Cancer Center Léman, Lausanne, Switzerland; Agora Cancer Research Center, Lausanne, Switzerland; Department of Oncology UNIL-CHUV, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland; Ludwig Institute for Cancer Research Lausanne Branch, Lausanne, Switzerland; Service of Immuno-Oncology, Department of Oncology UNIL-CHUV, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland; Service of Hematology and Central Laboratory of Hematology, Department of Oncology UNIL-CHUV and, Departments of Oncology, Laboratory Medicine and Pathology, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland. author Guichard Paul Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. 845268 Département de biologie moléculaire et cellulaire (MOCEL) author Hamel Virginie Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland. Electronic address: virginie.hamel@unige.ch. 846734 Département de biologie moléculaire et cellulaire (MOCEL) author Wolf Benita Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland; Swiss Cancer Center Léman, Lausanne, Switzerland; Agora Cancer Research Center, Lausanne, Switzerland; Department of Oncology UNIL-CHUV, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland. Electronic address: benita.wolf@chuv.ch. 403828 117165 10.1016/j.celrep.2026.117165 41926287 2211-1247 https://www.sciencedirect.com/science/article/pii/S2211124726002433 Cytotoxic T cell killing is executed at the immunological synapse, whose nanoscale organization underlies function but remains difficult to resolve in native states. Here, we apply cryo-expansion microscopy (cryo-ExM) to visualize the near-native three-dimensional architecture of human T cell synapses and cytotoxic organelles. Cryo-ExM preserves actin, microtubules, membranes, and fine membrane protrusions with high fidelity, enabling volumetric quantification of synapse morphogenesis. We identify an adhesion-dependent, dome-like membrane architecture beneath activated T cells that collapses upon ICAM-1 engagement, linking synapse topology to adhesive cues. Cryo-ExM further resolves intact lytic granules in primary human CD4 and CD8 T cells, revealing single-core and multi-core ultrastructures, spatial organization, and perforin and granzyme loading. Using tissue-adapted expansion microscopy, we map cytotoxic granule content in tumor-infiltrating T cells in FFPE human brain tumors. Together, these data establish a near-native structural framework for human T cell cytotoxicity and an imaging workflow bridging cell models and clinical tissues. 3D ultrastructure CP: immunology T cell cytotoxicity Cryo-expansion microscopy Cytotoxic granule deployment Immune synapse Lytic granules Tumor-infiltrating lymphocytes Dewey 610 Dewey 616 Dewey 570 Swiss National Science Foundation The architecture and molecular mechanisms of centriole assembly 205087 CH 56 Département de médecine 221 4f7589ed-e44d-4850-a4d8-b0c1eccdfe48 Centre de recherche translationnelle en onco-hématologie 209 7daed2ee-1311-4824-9df9-2e51260a966a Département de biologie moléculaire et cellulaire 16484 false 1310 Tumeurs cérébrales 1016 841 Groupe Guichard https://zenodo.org/records/18257076 https://github.com/Immuno-Oncology/Fiji-macros-expanded-T-cells Cell reports 45 4 e7c53880-75e1-4033-a2a6-b66547d7d106 Article (Published version) Public 1-s2.0-S2211124726002433-main.pdf 19528448 application/pdf CC BY-4.0 30bb0950025e734ed0b0cf0cd3ddd886f3a1597d0732b417ba30b4722b4f9307 b4f66690-525e-4f7e-ac74-2dd12f81f495 Supplemental data Public 1-s2.0-S2211124726002433-mmc1.pdf 1935053 application/pdf bbd1c9c382d907db8dbe75f9f731dc3e897fca8da8d01be5763204517842c327 64e22af4-1bd7-48f8-82b1-d6a145d52768 Supplemental data Public 1-s2.0-S2211124726002433-mmc11.pdf 47117980 application/pdf dc8392699153638239eedaf0ead703841a533dd478119c5b15ed0ce4dfd79fa4 Vignette Public 1-s2.0-S2211124726002433-fx1_lrg.jpg 249529 image/png openAccess Faculté de médecine / Section de médecine clinique / Département de médecine Faculté de médecine / Centre de recherche translationnelle en onco-hématologie Faculté des sciences / Section de biologie / Département de biologie moléculaire et cellulaire

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Unveiling the molecular architecture of T cells and immune synapses with cryo-expansion microscopy	Cell reports			2026	1	0

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Lemaitre, Florent