Figure 2.

Interactions of between B cells and other immune cells in AAA. B cells can differentiate into plasma cells and memory B cells under the stimulation of IL-4 from Th cells. Plasma cells continuously secrete immunoglobulins, which directly attack aortic walls. Specifically, IgE can activate macrophage polarization and mast cell degranulation and subsequently increase their productions of proteases such as MMPs and cathepsins. These factors work together in the pathogenesis of extracellular matrix degradation of aorta, and is an example of immune cell interactions in the whole process of AAA development. Figures were produced using Servier Medical Art (www.servier.com).