Figure 1.

Early events in inflammatory bowel disease (IBD). During the early stages of IBD, an imbalance between the immune system response and the physiological gut inflammation results in breakage of the mucosal barrier. This leads to increased intestinal permeability, antigen translocation to the lamina propria and into the circulatory system, and an increased number of resident immune cells (dendritic cells, macrophages, Th1, Th2, Th17, and B cells) which encounter the intestinal bacteria, leading to progression of inflammation.