Superantigens: biology, immunology, and potential role in disease.

Superantigens are unique products of bacteria and viruses which, in combination with class II major histocompatibility complex molecules, are capable of stimulating a large fraction of T cells in an affected individual. This stimulation primarily involves the variable region of the T cell receptor beta chain (V beta). The discovery of superantigens and the elucidation of their immunologic properties have provided valuable tools for the investigation of the immune system in both normal and diseased animals. Most importantly, recent work suggests that superantigens play a role in a number of diverse pathological conditions, including toxic shock syndrome and autoimmune diseases such as rheumatoid arthritis.