TCR binding differs for a bacterial superantigen (SEE) and a viral superantigen (Mtv-9).

TCR binding differs for a bacterial superantigen (SEE) and a viral superantigen (Mtv-9)

Both superantigens (SAG) and many anti-TCR monoclonal antibodies (mAb) have specificity for the V beta region of the TCR encoded by TCRBV genes. For instance the bacterial SAG staphylococcal enterotoxin E (SEE), the retroviral SAG MTV-9 and the mAb OT145 each react with human T cells expressing BV6S7. This BV gene encodes two common alleles. We found that SEE and the mAb preferentially activate...

Intercellular transfer of a soluble viral superantigen.

Mouse mammary tumor virus (MMTV) superantigens (vSAgs) can undergo intercellular transfer in vivo and in vitro such that a vSAg can be presented to T cells by major histocompatibility complex (MHC) class II proteins on antigen-presenting cells (APCs) that do not express the superantigen. This process may allow T-cell activation to occur prior to viral infection. Consistent with these findings, ...

Proteolytic processing activates a viral superantigen

Mouse mammary tumor virus (MMTV) superantigens (vSAg) undergo proteolytic processing at residues that have been demonstrated in vitro to be recognition sites for the endoprotease furin. To examine the role of furin in the presentation of vSAg7 to T cells, the vSAg7 and class II MHC IEk genes were introduced into Chinese Hamster Ovary (CHO) cells (furin-positive) and into a furin-negative CHO va...

Macaque TCR Repertoires In Vivo Effects of a Bacterial Superantigen on

Cutting edge: trimolecular interaction of TCR with MHC class II and bacterial superantigen shows a similar affinity to MHC:peptide ligands.

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 ...