Event Abstract Back to Event Germline TSC1 mutations are permissive for T lymphocyte development and homeostasis in Tuberous Sclerosis individuals. Karolina Pilipow1, 2*, Veronica Basso2, Nicola Migone3 and Anna Mondino2 1 Vita-Salute San Raffaele University, Italy 2 San Raffaele Scientific Institute, Italy 3 University of Turin, Department of Genetics, Biology and Biochemistry, Italy Antigen recognition on the surface of antigen presenting cells initiate a variety of intracellular signals critical for naïve T cells to commit to proliferate and differentiate. Others and we have shown the TSC/mTOR axis to be critical in coordinating cell quiescence, proliferation and fate determination. Blocking mTOR by Rapamycin, or genetic inactivation of components of the mTOR Complex (mTORC) or TSC1, unbalances mTORC1 and mTORC2 regulation, impacting on cell quiescence, proliferation and differentiation. In humans, germline mutations of TSC1 predispose to Tuberous Sclerosis Complex disease, an autosomal dominant disorder characterized by multifocal hamartomatosis. Whether such mutations impact on T cell functions in these individuals was unknown. To this aim we analyzed subset representation, phenotype and function of T cells from two independent families with characterized mutations of TSC1 in parallel to T cells from healthy volunteers and to mouse T cells with mono- or bilallelic deletion of Tsc1 (from T-lineage restricted Tsc1+/- and Tsc1-/- mice). We found that heterozygosis of Tsc1/TSC1 is sufficient for proper hamartin expression and both homeostatic and TCR-induced mTORC1 and mTORC2-dependent signaling in mice and human T cells. In contrast, loss of Tsc1/TSC1 following biallelic genetic inactivation and shRNA-induced down-regulation unbalanced mTORC-dependent FOXO1/3 regulation, leading to loss of mitochondrial potential apoptotic cell death. Thus, while heterozygosis of Tsc1/TSC1 is sufficient for proper T lymphocyte development and homeostasis, its more severe loss is incompatible with both mouse and human T cell survival. Acknowledgements The authors wish to thank TSC subjects and their family for support, members of the San Raffaele Scientific Institute for suggestions, Dr Rossella Galli for Tsc1 fl/fl mice, Dr Ruggero Pardi for CD4cre mice and Dr Vincenzo Calautti (Dulbecco Telethon Institute, Molecular Biotechnology Center, University of Turin) for the help with TSC1 shRNA. This work was supported by the Associazione Italiana Ricerca sul Cancro. KP benefited of fellowships from the San Raffaele Vita-Salute University and FIRC. Keywords: T lymphocytes, Intracellular signaling, TSC/mTOR, intrinsic apoptosis, Tuberous Sclerosis Complex Disease Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Adaptive Immunity Citation: Pilipow K, Basso V, Migone N and Mondino A (2013). Germline TSC1 mutations are permissive for T lymphocyte development and homeostasis in Tuberous Sclerosis individuals.. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00976 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Karolina Pilipow, Vita-Salute San Raffaele University, Milan, Italy, kpilipow@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Karolina Pilipow Veronica Basso Nicola Migone Anna Mondino Google Karolina Pilipow Veronica Basso Nicola Migone Anna Mondino Google Scholar Karolina Pilipow Veronica Basso Nicola Migone Anna Mondino PubMed Karolina Pilipow Veronica Basso Nicola Migone Anna Mondino Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.
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