Cutting edge: trimolecular interaction of TCR with MHC class II and bacterial superantigen shows a similar affinity to MHC:peptide ligands.
Published
Journal Article
Bacterial superantigens such as Staphylococcus aureus enterotoxin A (SEA) are very potent stimulators of T cells. They bind to the Vbeta region of the TCR and to MHC class II, stimulating T cells at nanomolar concentrations. Using surface plasmon resonance measurements, we find that binding between the individual components of the complex (TCR-class II, TCR-SEA, SEA-class II) is very weak, but that the stability of the trimolecular complex is considerably enhanced, reaching an affinity similar to that found for TCR interactions with MHC:peptide ligand. Thus, the potency of SEA in stimulation of T cells is not due to particularly strong affinities between the proteins, but to a cooperative effect of interactions in the TCR-SEA-MHC class II trimolecular complex that brings the kinetics into a similar range to binding of conventional Ags. This range may be the optimum for T cell activation.
Full Text
Duke Authors
Cited Authors
- Redpath, S; Alam, SM; Lin, CM; O'Rourke, AM; Gascoigne, NR
Published Date
- July 1, 1999
Published In
Volume / Issue
- 163 / 1
Start / End Page
- 6 - 10
PubMed ID
- 10384091
Pubmed Central ID
- 10384091
International Standard Serial Number (ISSN)
- 0022-1767
Language
- eng
Conference Location
- United States