(9f) Simulating Lymphocytes Dynamics within the Lymph Node Towards Complex Cellular Distribution Patterns

The mechanisms that guide the migration of lymphocytes and dendritic cells towards specific locations within the lymph node are not well understood. Experimental evidence support both the cellular haptotaxis, induced by chemokine gradients, and the random-walk-like behavior of trafficking cells. A multi-scale simulation approach, including random-walk and haptotactic cellular migration of lymphocytes and dendritic cells, is proposed. A Galerkin finite element simulation method is used to evolve the continuum dynamics, whereas Brownian dynamics are used to study cell activation of discrete coarse-grain cell models. Cell migration and activation within the lymph node are studied by comparing the relevant diffusive mechanisms. In the continuum scale, non-uniform mobility coefficients and chemo-attractive diffusion are included in the species balance. On the other hand, first order kinetics are included in Brownian dynamics to study cell activation. The proposed approach serves to understand complex dynamics of immune cell activation, including the inflammatory response and complement activation.