A Review on Superantigens

Superantigens are microbial products which are immunostimulatory and disease causing. They stimulate a large fraction of T cells unlike conventional antigens. These superantigens include various staphylococcal enterotoxins, streptococcal toxic shock syndrome toxins, viral proteins etc. The superantigen family comprise of proteins that range from 22-29 kDa in size and highly resistant to proteases and heat denaturation. Superantigens posses an N- and C- terminal domain divided by a long, solvent accessible -helix which spans the centre of the molecule and contains several hydrophobic residues in its solvent-exposed regions while the C-terminal domain adopts a grasp motif. Various human diseases are caused by superantigens as food poisoning, toxic shock syndrome, Kawasaki disease and some autoimmune disorders. Different approaches have been developed for the effective protection and treatment of superantigens based diseases. The ability of superantigens to stimulate a large population of T-cells has been explored for cancer immunotherapy and treatment of infection and autoimmune diseases.