A stochastic model for cytotoxic T. Lymphocyte interaction with tumor nodules

Résumé

CTL (Cytotoxic T. Lymphocytes) destroy virally infected cells and tumor cells via the secretion of lytic molecules stored in intracellular granules. They are key components of the anti-cancer immune response and it is therefore crucial to study in depth, and possibly enhance, their biological responses against tumors. In [CMR+15], we introduced a stochastic dynamical model that involves interacting particles based on experimentally measured parameters. It therefore makes it possible to describe CTL function during immuno-editing. At the same time, we showed on simulations that a bias in CTL motility inducing a progressive attraction towards a few scout CTL, which have detected the nodule, enhances early productive collisions and drastically improves the tumor eradication rate. In the present paper, we introduce a continuous time similar model and derive rigorously formulas for the evolution of the system CTL/Nodule. Numerical schemes then confirm the quantitative role of the bias in the CTL movement induced by scout CTL, and open new perspectives on chemotaxis for immunotherapy.