- They do not need to be processed.
- Able to activate all T cells irrespective of their antigen specificity.
- They interact with MHC molecules outside the peptide binding groove.
- Also bind with TCR β chain irrespective of antigen specificity.
- Polyclonal activation of T cells.
- They stimulate the release of abnormal large amounts of cytokines especially TNF.
- It can lead to shock.
- Staphylococcal enterotoxin.
- Staphylococcal toxic shock syndrome toxins (TSST).
- Staphylococcal exfoliative toxin.
- Streptococcal pyrogenic exotoxins.