Allergic diseases and the role of mast cells and follicular T helper cells

Role of mast cells and follicular T helper cells (TFH) that are implicated in the pathogenesis of allergic diseases. This is the fruit of the research activity of Dr. Gilda Varricchi, Research Fellow (RTDB) of Internal Medicine at the Department of Translational Medical Sciences (DISMET) of the Federico II University and member of the Interdepartmental Center for Basic and Clinical Immunological Sciences (CISI) and the WAO Center of Excellence.

This research, conducted in part in collaboration with the group of Professor Petri T. Kovanen of the Wihuri Research Institute at the University of Helsinki, Finland, was published in the prestigious journal Trends in Immunology (August 2020).

Specifically, the research showed that lung and skin mast cells and their chemical mediators play a pro-inflammatory role in allergic diseases. Currently, Varricchi has shown that mast cells can be evidenced in all compartments (ventricles, atria, heart valves, coronary arteries and pericardium) of the human heart. Surprisingly, cardiac mast cells may play an unexpected protective role in several cardiovascular diseases. In fact, these immune cells produce pro-angiogenic factors, such as Vascular Endothelial Growth Factor-A (VEGF-A), which, acting on endothelial cells, increase the coronary circulation. In addition, cardiac mast cells produce lymphangiogenic factors, such as VEGF-C, which promote lymph outflow at the lymphatics of the heart. Through this mechanism, mast cells and the VEGF-C produced by them may contribute to the resolution of cardiac inflammation. Confirming these observations, mast cell tryptase has been shown to activate certain receptors (PAR2) on cardiomyocytes, inducing a protective effect in experimental infarction.

Dr. Varricchi received her Ph.D. in Immunological Sciences from Imperial College London doing research in the Department of Clinical Immunology and Allergy.