Stochastic models for CD4+ T cells

In this thesis, we study the mechanisms involved in CD4+ T cell activation focusing on the crucial role of costimulation for an effective immune response. For this purpose, interactions between receptors from T cells and ligands on the APCs, as well as the trafficking of these molecules, need to be analysed. At the same time, population models are developed to study their homeostatic behaviour and the role of IL-2, as well as quorum-sensing mechanisms in CD4+ T cell maintenance.
A multidisciplinary approach that combines statistical analysis of experimental data and mathematical models that describe the experiments, has been used that take into account the stochastic nature of these processes. We have combined deterministic methods when appropriate with stochastic ones, as well as made us of numerical simulations.