HSP60 speaks to the immune system in many voices.

Heat shock proteins (HSP) were initially identified as a family of stress-induced proteins characterized by their chaperone activity. HSP, however, are also important players in the control of the immune response: HSP are targeted by HSP-specific T cells and antibodies in healthy subjects and also during the course of autoimmune disorders and, conversely, HSP influence the activity of several immune cell types via innate receptor signalling pathways. In addition, the immune response to HSP can be mined for information on the state of the immune system. Newborns carry autoantibodies to HSP. However, this natural autoreactivity to HSP is modified by inflammation, and these changes can be monitored as biomarkers during postnatal life. Using antigen microarrays, we have shown that autoantibody patterns identify individuals prone to develop autoimmune diabetes before disease onset. Moreover, changes in the inflammatory process in multiple sclerosis are also reflected in the antibody response to self-HSP. Herein, we discuss the relevance of HSP and their immune activities for the regulation and monitoring of inflammation and autoimmune disease.