Abstract
Superantigens are classified into 3 groups, bacterial, viral and plant. The first are products mainly of virulent pathogenic bacteria, such as Staphylococcus aureus, Streptococcus pyogenes and Yersinia pseudotuberculosis. The second are products mainly of endogenous or exogenous mouse mammary tumor viruses. A lectin from stinging nettle rhizome (Urtica dioica) was reported as a plant superantigen. Superantigens activate T cells in a TCR Vβ selective way in association with MHC class II molecules expressed on accessory cells, such as macrophages or dendritic cells. Most of the bacterial superantigens have been implicated in the pathogenesis of certain infectious diseases, such as toxic shock syndrome, scarlet fever, and Yersinia pseudotuberculosis infection. We consider that overactivation of T cells by bacterial superantigens is primarily involved in the pathogenesis of the infectious diseases caused by these bacteria.
In addition, it was reported that superantigenic factors are involved in the pathogenesis of Kawasaki disease, psoriasis, insulin-dependent diabetes melitus and rheumatoid arthritis. So far concrete evidences have not been obtained on the involvement of superantigenic pathogens in these autoimmune diseases. The concept of superantigen would increase its importance on the investigation of pathogenic mechanisms of infectious, inflammatory and autoimmune diseases.
