  Immune system is the most important defense system to resist human pathogens.
In this paper we present an immune model with bipartite graphs theory. We
collect data through COPE database and construct an immune cell- mediators
network. The act degree distribution of this network is proved to be power-law,
with index of 1.8. From our analysis, we found that some mediators with high
degree are very important mediators in the process of regulating immune
activity, such as TNF-alpha, IL-8, TNF-alpha receptors, CCL5, IL-6, IL-2
receptors, TNF-beta receptors, TNF-beta, IL-4 receptors, IL-1 beta, CD54 and so
on. These mediators are important in immune system to regulate their activity.
We also found that the assortative of the immune system is -0.27. It reveals
that our immune system is non-social network. Finally we found similarity of
the network is 0.13. Each two cells are similar to small extent. It reveals
that many cells have its unique features. The results show that this model
could describe the immune system comprehensive.
