Exercise-Induced Chaperokine Activity of Hsp70: Possible Role in Chronic Diseases

In recent years, strong effects of exercise on the immune system have been demonstrated in many studies. Indeed, beneficial effects of regular exercise on immune responses in diseases such as cancer, cardiovascular disease, neuromuscular disorders and diabetes have been observed. Growing evidence indicates that the stress-inducible form of Hsp70 (Hsp70; 72 kDa) is found in the extracellular milieu and can exert chaperoning and regulatory effects on various immunocompetent cells. In this regard, extracellular Hsp72 can stimulate immune responses such as macrophages, T lymphocytes and NK cells. We propose that extracellular Hsp72 is released following acute exercise and acts to stimulate the immune system. The chaperokine activity of eHsp72 would constitute one mechanism for cross talk between tissues after exercise and the adaptation to physical exercise. Here, we discuss the immunostimulatory and immunosuppressive activities of eHsp72 as a possible mechanism for the protective effects of regular physical exercise in chronic disease.