Here is a drawing that explains the two different types of macrophges we became interested in.
The M1 macrophages are the aggressive type of macrophage and produce IP-10, MIG and IL-6.
The M2 macrophages are much more accepting and help decrease the immune response. M2 macrophages make CCL22, CCL17, Arg1, Mrc and IL-10.
Our results in the mouse heart shows that in the chronic rejection model we were seeing M2 type macrophages since we had found an increase in CCL22 and CCL17.