المؤلفون: Chang, H-F, Schirra, C, Ninov, M, Hahn, U, Ravichandran, K, Krause, E, Becherer, U, Bálint, Š, Harkiolaki, M, Urlaub, H, Valitutti, S, Baldari, CT, Dustin, ML, Jahn, R, Rettig, J

الوصف: Cytotoxic T lymphocytes (CTL) kill malignant and infected cells through the directed release of cytotoxic proteins into the immunological synapse (IS). The cytotoxic protein granzyme B (GzmB) is released in its soluble form or in supramolecular attack particles (SMAP). We utilize synaptobrevin2-mRFP knock-in mice to isolate fusogenic cytotoxic granules in an unbiased manner and visualize them alone or in degranulating CTLs. We identified two classes of fusion-competent granules, single core granules (SCG) and multi core granules (MCG), with different diameter, morphology and protein composition. Functional analyses demonstrate that both classes of granules fuse with the plasma membrane at the IS. SCG fusion releases soluble GzmB. MCGs can be labelled with the SMAP marker thrombospondin-1 and their fusion releases intact SMAPs. We propose that CTLs use SCG fusion to fill the synaptic cleft with active cytotoxic proteins instantly and parallel MCG fusion to deliver latent SMAPs for delayed killing of refractory targets.

العلاقة: https://ora.ox.ac.uk/objects/uuid:f57590aa-baf3-4800-8bda-48b675f3ffa4Test; https://doi.org/10.1038/s41467-022-28596-yTest

الإتاحة: https://doi.org/10.1038/s41467-022-28596-yTest
https://ora.ox.ac.uk/objects/uuid:f57590aa-baf3-4800-8bda-48b675f3ffa4Test

المؤلفون: Chang, H., Schirra, C., Ninov, M., Hahn, U., Ravichandran, K., Krause, E., Becherer, U., Bálint, Š., Harkiolaki, M., Urlaub, H., Valitutti, S., Baldari, C., Dustin, M., Jahn, R., Rettig, J.

المصدر: Nature Communications

الوصف: Cytotoxic T lymphocytes (CTL) kill malignant and infected cells through the directed release of cytotoxic proteins into the immunological synapse (IS). The cytotoxic protein granzyme B (GzmB) is released in its soluble form or in supramolecular attack particles (SMAP). We utilize synaptobrevin2-mRFP knock-in mice to isolate fusogenic cytotoxic granules in an unbiased manner and visualize them alone or in degranulating CTLs. We identified two classes of fusion-competent granules, single core granules (SCG) and multi core granules (MCG), with different diameter, morphology and protein composition. Functional analyses demonstrate that both classes of granules fuse with the plasma membrane at the IS. SCG fusion releases soluble GzmB. MCGs can be labelled with the SMAP marker thrombospondin-1 and their fusion releases intact SMAPs. We propose that CTLs use SCG fusion to fill the synaptic cleft with active cytotoxic proteins instantly and parallel MCG fusion to deliver latent SMAPs for delayed killing of refractory targets.

وصف الملف: application/pdf

العلاقة: http://hdl.handle.net/21.11116/0000-000A-90FD-6Test; http://hdl.handle.net/21.11116/0000-000A-90FF-4Test

الإتاحة: https://doi.org/10.1038/s41467-022-28596-yTest
http://hdl.handle.net/21.11116/0000-000A-90FD-6Test
http://hdl.handle.net/21.11116/0000-000A-90FF-4Test

المؤلفون: Balint, Š, Müller, S, Fischer, R, Kessler, BM, Harkiolaki, M, Valitutti, S, Dustin, ML

الوصف: Cytotoxic T lymphocytes (CTLs) kill infected and cancerous cells. We detected transfer of cytotoxic multiprotein complexes from CTLs to target cells, termed supramolecular attack particles (SMAPs). SMAPs were rapidly released from CTLs and were autonomously cytotoxic. Mass spectrometry, immunochemical analysis and CRISPR editing identified a C-terminal fragment of thrombospondin-1 as an unexpected SMAP component that contributed to target killing. Direct stochastic optical reconstruction microscopy resolved a cytotoxic core surrounded by a thrombospondin-1 shell of ~120 nm diameter. Cryo-soft x-ray tomography analysis revealed that SMAPs had a carbon-dense shell and were stored in multicore granules. We propose that SMAPs are autonomous extracellular killing entities that deliver cytotoxic cargo based on specificity of shell components.

العلاقة: https://ora.ox.ac.uk/objects/uuid:98e77a82-64ef-4168-bd83-9eae48a25747Test; https://doi.org/10.1126/science.aay9207Test

الإتاحة: https://doi.org/10.1126/science.aay9207Test
https://ora.ox.ac.uk/objects/uuid:98e77a82-64ef-4168-bd83-9eae48a25747Test

المؤلفون: Dushek, O, Mueller, S, Soubies, S, Depoil, D, Caramalho, I, Coombs, D, Valitutti, S

الوصف: BACKGROUND: The activation of T lymphocytes by specific antigen is accompanied by the formation of a specialized signaling region termed the immunological synapse, characterized by the clustering and segregation of surface molecules and, in particular, by T cell receptor (TCR) clustering. METHODOLOGY/PRINCIPAL FINDINGS: To better understand TCR motion during cellular activation, we used confocal microscopy and photo-bleaching recovery techniques to investigate the lateral mobility of TCR on the surface of human T lymphocytes under various pharmacological treatments. Using drugs that cause an increase in intracellular calcium, we observed a decrease in TCR mobility that was dependent on a functional actin cytoskeleton. In parallel experiments measurement of filamentous actin by FACS analysis showed that raising intracellular calcium also causes increased polymerization of the actin cytoskeleton. These in vitro results were analyzed using a mathematical model that revealed effective binding parameters between TCR and the actin cytoskeleton. CONCLUSION/SIGNIFICANCE: We propose, based on our results, that increase in intracellular calcium levels leads to actin polymerization and increases TCR/cytoskeleton interactions that reduce the overall mobility of the TCR. In a physiological setting, this may contribute to TCR re-positioning at the immunological synapse.

العلاقة: https://ora.ox.ac.uk/objects/uuid:c4b1b6ff-b5f6-43fd-94ce-9cf8ea0999d0Test; https://doi.org/10.1371/journal.pone.0003913Test

الإتاحة: https://doi.org/10.1371/journal.pone.0003913Test
https://ora.ox.ac.uk/objects/uuid:c4b1b6ff-b5f6-43fd-94ce-9cf8ea0999d0Test

المؤلفون: Chiaruttini, G., Piperno, G.M., Jouve, M., De Nardi, F., Larghi, P., Peden, A.A., Baj, G., Müller, S., Valitutti, S., Galli, T., Benvenuti, F.

الوصف: Interleukin-12 (IL-12), produced by dendritic cells in response to activation, is central to pathogen eradication and tumor rejection. The trafficking pathways controlling spatial distribution and intracellular transport of IL-12 vesicles to the cell surface are still unknown. Here, we show that intracellular IL-12 localizes in late endocytic vesicles marked by the SNARE VAMP7. Dendritic cells (DCs) from VAMP7-deficient mice are partially impaired in the multidirectional release of IL-12. Upon encounter with antigen-specific T cells, IL-12-containing vesicles rapidly redistribute at the immune synapse and release IL-12 in a process entirely dependent on VAMP7 expression. Consistently, acquisition of effector functions is reduced in T cells stimulated by VAMP7-null DCs. These results provide insights into IL-12 intracellular trafficking pathways and show that VAMP7-mediated release of IL-12 at the immune synapse is a mechanism to transmit innate signals to T cells.

وصف الملف: text

العلاقة: https://eprints.whiterose.ac.uk/105416/1/1-s2.0-S2211124716301760-main.pdfTest; Chiaruttini, G., Piperno, G.M., Jouve, M. et al. (8 more authors) (2016) The SNARE VAMP7 Regulates Exocytic Trafficking of Interleukin-12 in Dendritic Cells. Cell Reports, 14 (11). pp. 2624-2636. ISSN 2211-1247

الإتاحة: https://doi.org/10.1016/j.celrep.2016.02.055Test
https://eprints.whiterose.ac.uk/105416Test/
https://eprints.whiterose.ac.uk/105416/1/1-s2.0-S2211124716301760-main.pdfTest

المؤلفون: Espagnolle, N., Depoil, D., Zaru, R., Demeur, C., Champagne, E., Guiraud, M., Valitutti, S.

المصدر: International Immunology ; volume 19, issue 3, page 239-248 ; ISSN 0953-8178 1460-2377

مصطلحات موضوعية: Immunology, General Medicine, Immunology and Allergy

الإتاحة: https://doi.org/10.1093/intimm/dxl141Test
http://academic.oup.com/intimm/article-pdf/19/3/239/2458751/dxl141.pdfTest

المؤلفون: Rabot, M., El Costa, H., Polgar, B., Marie-Cardine, A., Aguerre-Girr, M., Barakonyi, A., Valitutti, S., Bensussan, A., Le Bouteiller, P.

المصدر: International Immunology ; volume 19, issue 4, page 401-409 ; ISSN 0953-8178 1460-2377

مصطلحات موضوعية: Immunology, General Medicine, Immunology and Allergy

الإتاحة: https://doi.org/10.1093/intimm/dxm005Test
http://academic.oup.com/intimm/article-pdf/19/4/401/2026374/dxm005.pdfTest

المؤلفون: Abreu, A., Frenoist, F.X., Valitutti, S., Brousset, P., Denefle, P., Naegel, B., Wemmert, C.

المصدر: 2018 24th International Conference on Pattern Recognition (ICPR)

الإتاحة: https://doi.org/10.1109/icpr.2018.8546011Test
http://xplorestaging.ieee.org/ielx7/8527858/8545020/08546011.pdf?arnumber=8546011Test

المؤلفون: Valmori, D., Fonteneau, J.F., Valitutti, S., Gervois, N., Dunbar, R., Liénard, D., Rimoldi, D., Cerundolo, V., Jotereau, F., Cerottini, J.C., Speiser, D.E., Romero, P.

المصدر: International immunology, vol. 11, no. 12, pp. 1971-80

مصطلحات موضوعية: Antigens, Neoplasm, Calcium, Cell Line, Cytokines, Cytotoxicity, Immunologic, Humans, Lymphocyte Activation, Melanoma, Neoplasm Proteins, Receptors, Antigen, T-Cell, T-Lymphocytes

الوصف: Many mechanisms have been proposed to explain why immune responses against human tumor antigens are generally ineffective. For example, tumor cells have been shown to develop active immune evasion mechanisms. Another possibility is that tumor antigens are unable to optimally stimulate tumor-specific T cells. In this study we have used HLA-A2/Melan-A peptide tetramers to directly isolate antigen-specific CD8(+) T cells from tumor-infiltrated lymph nodes. This allowed us to quantify the activation requirements of a representative polyclonal yet monospecific tumor-reactive T cell population. The results obtained from quantitative assays of intracellular Ca(2+) mobilization, TCR down-regulation, cytokine production and induction of effector cell differentiation indicate that the naturally produced Melan-A peptides are weak agonists and are clearly suboptimal for T cell activation. In contrast, optimal T cell activation was obtained by stimulation with recently defined peptide analogues. These findings provide a molecular basis for the low immunogenicity of tumor cells and suggest that patient immunization with full agonist peptide analogues may be essential for stimulation and maintenance of anti-tumor T cell responses in vivo.

وصف الملف: application/pdf

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/10590263; info:eu-repo/semantics/altIdentifier/pissn/0953-8178; info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_943F39FA15D77; https://serval.unil.ch/notice/serval:BIB_943F39FA15D7Test; https://serval.unil.ch/resource/serval:BIB_943F39FA15D7.P001/REF.pdfTest; http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_943F39FA15D77Test

الإتاحة: https://doi.org/10.1093/intimm/11.12.1971Test
https://serval.unil.ch/notice/serval:BIB_943F39FA15D7Test
https://serval.unil.ch/resource/serval:BIB_943F39FA15D7.P001/REF.pdfTest
http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_943F39FA15D77Test

المؤلفون: Abreu, A., Frenois, F.-X., Valitutti, S., Brousset, P., Denefle, P., Naegel, B., Wemmert, C.

المصدر: Proceedings of the 10th International Symposium on Image and Signal Processing and Analysis

الإتاحة: https://doi.org/10.1109/ispa.2017.8073594Test
http://xplorestaging.ieee.org/ielx7/8063640/8073550/08073594.pdf?arnumber=8073594Test