a population dynamics analysis of the interaction between adaptive regulatory t cells and antigen presenting cells之间的相互作用的种群动态分析适应性调节性t细胞和抗原呈递细胞.pdfVIP

A Population Dynamics Analysis of the Interaction between Adaptive Regulatory T Cells and Antigen Presenting Cells David Fouchet*, Roland Regoes ¨ ¨ ¨ ¨ Institute of Integrative Biology, Die Eidgenossische Technische Hochschule (ETH) Zurich, Die Eidgenossische Technische Hochschule (ETH) Zentrum, Zurich, Switzerland Abstract Background: Regulatory T cells are central actors in the maintenance of tolerance of self-antigens or allergens and in the regulation of the intensity of the immune response during infections by pathogens. An understanding of the network of the interaction between regulatory T cells, antigen presenting cells and effector T cells is starting to emerge. Dynamical systems analysis can help to understand the dynamical properties of an interaction network and can shed light on the different tasks that can be accomplished by a network. Methodology and Principal Findings: We used a mathematical model to describe a interaction network of adaptive regulatory T cells, in which mature precursor T cells may differentiate into either adaptive regulatory T cells or effector T cells, depending on the activation state of the cell by which the antigen was presented. Using an equilibrium analysis of the mathematical model we show that, for some parameters, the network has two stable equilibrium states: one in which effector T cells are strongly regulated by regulatory T cells and another in which effector T cells are not regulated because the regulatory T cell population is vanishingly small. We then simulate different types of perturbations, such as the introduction of an antigen into a virgin system, and look at the state into which the system falls. We find that whether or not the int