Interaction of the T cell receptor with bacterial superantigens

Bacterial toxin superantigens bind to MHC class II molecules and activate a large proportion of T cells through a direct interaction with the T cell receptor (TCR). The toxin: TCR interaction involves specific recognition between the beta-chain variable region and the toxin. Although a complete alpha beta T cell receptor is required for activation of T cells, studies using purified soluble T cell receptor beta-chain have shown that it alone is sufficient for binding the toxin: class II complex. The regions of V beta and enterotoxin involved in the recognition have been determined.