Body-wide modelling of immune cell circulation in the blood flow Body-wide modelling of immune cell circulation in the blood flow

Low grade inflammation is involved in many non-communicable diseases, such as osteoarthritis, intervertebral disc degeneration or atherosclerosis, among others. The common characteristic of these diseases is a silent evolution over decades before the pathogenesis becomes irreversible and the symptoms highly disabling. The regulation of low-grade inflammation takes place at the systemic level and involves whole-body communications. To date, no enabling simulation technology exists to mechanistically approximate and anticipate these communications and the most relevant perturbations thereof. Hence, this project targets the construction of a body-wide agent-based (AB) model of white blood cell transport, as an enabling technology for the exploration of low-grade inflammation effects.

The high-resolution cryosection images of Yoon-Sum (26 years old woman) and Jeduk (33 years old man), from the IT’IS Computable Virtual Population will be used to generate an interconnected network of 2D AB grids of the human vascular system, including the detail of the vessels that reach the organs. The local width of the 2D grid through the model will match the local diameter of the segmented vessels. The model will be inspired from the AB modelling frameworks used in geographical information science, such as allowed by the agent modelling codes Repast and Mesa, and parallel computing-compatible libraries will be used to reach simulations with 1.106 agents. These agents will stand for circulating monocytes and neutrophils, and patch to patch agent mobility will be imposed according to mean regional blood velocity approximation. Agent mobility simulations will be coupled to the diffusion of biochemical substances such as cytokines, able to generate agent cooperation at the system level.