title: Comprehensive assessment and mathematical modeling of T cell population dynamics and homeostasis.
abstract: Our current view of T cell differentiation and population dynamics is assembled from pieces of data obtained from separate experimental systems and is thus patchy. We reassessed homeostasis and dynamics of T cells 1) by generating a mathematical model describing the spatiotemporal features of T cell differentiation, and 2) by fitting this model to experimental data generated by disturbing T cell differentiation through transient depletion of dividing T cells in mice. This specific depletion was obtained by administration of ganciclovir to mice expressing the conditional thymidine kinase suicide gene in T cells. With this experimental approach, we could derive quantitative parameters describing the cell fluxes, residence times, and rates of import, export, proliferation, and death across cell compartments for thymocytes and recent thymic emigrants (RTEs). Among other parameters, we show that 93% of thymocytes produced before single-positive stages are eliminated through the selection process. Then, a postselection peripheral expansion of naive T cells contributes three times more to naive T cell production than the thymus, with half of the naive T cells consisting of dividing RTEs. Altogether, this work provides a quantitative population dynamical framework of thymocyte development, RTEs, and naive T cells.
authors.affiliation: Unité Mixte de Recherche 7087, Biologie et Thérapeutique des Pathologies Immunitaires, Université Pierre et Marie Curie-Paris 06, 83 Boulevard de l'Hôpital, Paris, France. thomas@chups.jussieu.fr
authors.forename: Véronique
authors.initials: V
authors.lastname: Thomas-Vaslin
authors.forename: Hester Korthals
authors.initials: HK
authors.lastname: Altes
authors.forename: Rob J
authors.initials: RJ
authors.lastname: de Boer
authors.forename: David
authors.initials: D
authors.lastname: Klatzmann
mesh_terms: D000818:Animals; D016923:Cell Death / Q000235:genetics / Q000276:immunology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology*; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D002465:Cell Movement / Q000235:genetics / Q000276:immunology*; D048749:Cytokinesis / Q000235:genetics / Q000276:immunology; D015774:Ganciclovir / Q000008:administration & dosage; D018259:Herpesvirus 1, Human / Q000235:genetics; D006706:Homeostasis / Q000235:genetics / Q000276:immunology*; D018655:Lymphocyte Count; D008212:Lymphocyte Depletion; D051379:Mice; D008822:Mice, Transgenic; D018448:Models, Immunological; D016192:Resting Phase, Cell Cycle / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000201:enzymology / Q000276:immunology*; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D013937:Thymidine Kinase; D015774:Ganciclovir