title: Modeling lymphocyte homing and encounters in lymph nodes.
abstract: BACKGROUND
  The efficiency of lymph nodes depends on tissue structure and organization, which allow the coordination of lymphocyte traffic. Despite their essential role, our understanding of lymph node specific mechanisms is still incomplete and currently a topic of intense research.
  
  
  RESULTS
  In this paper, we present a hybrid discrete/continuous model of the lymph node, accounting for differences in cell velocity and chemotactic response, influenced by the spatial compartmentalization of the lymph node and the regulation of cells migration, encounter, and antigen presentation during the inflammation process.
  
  
  CONCLUSIONS
  Our model reproduces the correct timing of an immune response, including the observed time delay between duplication of T helper cells and duplication of B cells in response to antigen exposure. Furthermore, we investigate the consequences of the absence of dendritic cells at different times during infection, and the dependence of system dynamics on the regulation of lymphocyte exit from lymph nodes. In both cases, the model predicts the emergence of an impaired immune response, i.e., the response is significantly reduced in magnitude. Dendritic cell removal is also shown to delay the response time with respect to normal conditions.
authors: Istituto per le Applicazioni del Calcolo M, Picone, Consiglio Nazionale delle Ricerche (CNR), c/o IASI-CNR, V,le Manzoni 30, 00185 - Rome, Italy. valentina.baldazzi@inria.fr
authors: Valentina
authors: V
authors: Baldazzi
authors: Paola
authors: P
authors: Paci
authors: Massimo
authors: M
authors: Bernaschi
authors: Filippo
authors: F
authors: Castiglione
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002465:Cell Movement / Q000502:physiology; D019295:Computational Biology / Q000379:methods*; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008198:Lymph Nodes / Q000502:physiology*; D008214:Lymphocytes / Q000502:physiology*; D008954:Models, Biological