title: Quantifying the relevance of different mediators in the human immune cell network.
abstract: BACKGROUND
  Immune cells coordinate their efforts for the correct and efficient functioning of the immune system (IS). Each cell type plays a distinct role and communicates with other cell types through mediators such as cytokines, chemokines and hormones, among others, that are crucial for the functioning of the IS and its fine tuning. Nevertheless, a quantitative analysis of the topological properties of an immunological network involving this complex interchange of mediators among immune cells is still lacking.
  
  
  RESULTS
  Here we present a method for quantifying the relevance of different mediators in the immune network, which exploits a definition of centrality based on the concept of efficient communication. The analysis, applied to the human IS, indicates that its mediators differ significantly in their network relevance. We found that cytokines involved in innate immunity and inflammation and some hormones rank highest in the network, revealing that the most prominent mediators of the IS are molecules involved in these ancestral types of defence mechanisms which are highly integrated with the adaptive immune response, and at the interplay among the nervous, the endocrine and the immune systems.
  
  
  BACKGROUND
  claudio.franceschi@unibo.it.
authors.affiliation: Dipartimento di Patologia Sperimentale, Università di Bologna, Via San Giacomo 12, 40126 Bologna, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Tieri
authors.forename: S
authors.initials: S
authors.lastname: Valensin
authors.forename: V
authors.initials: V
authors.lastname: Latora
authors.forename: G C
authors.initials: GC
authors.lastname: Castellani
authors.forename: M
authors.initials: M
authors.lastname: Marchiori
authors.forename: D
authors.initials: D
authors.lastname: Remondini
authors.forename: C
authors.initials: C
authors.lastname: Franceschi
mesh_terms: D000936:Antigen-Antibody Complex / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology; D003198:Computer Simulation; D016207:Cytokines / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D018836:Inflammation Mediators / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D018448:Models, Immunological; D015398:Signal Transduction / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D016207:Cytokines; D018836:Inflammation Mediators