V alpha domain modulates the multiple topologies of mouse T cell receptor V beta20/staphylococcal enterotoxins A and E complexes.
The superantigens staphylococcal enterotoxin A and E (SEA and SEE) both contact major histocompatibility complex (MHC) class II molecules on two sites located on the alpha and beta chains. We have investigated the role of the T cell receptor (TCR) alpha chain in the modulation of the various topologies of TCR/SEA (or SEE)/class II complexes. For this purpose, we have used three mouse V beta20 T cell lines expressing different V alpha domains and two T cell hybridomas expressing mouse V beta1 or V beta11 segments. The response of these T cells to SEA and SEE was studied in the context of presentation by wild-type human MHC class II molecules; or by mutants on MHC, in each of the two superantigen binding sites (position alpha39K and beta81H) to which the superantigens can still bind but with an altered conformation. Although V beta20 T cell lines are efficiently stimulated using SEA and SEE presented by wild-type HLA-DR1 molecules, our results show that the nature of the TCR V alpha domain can affect differently the recognition of the toxins bound to mutant class II molecules. This suggests that various functional topologies exist for both SEA and SEE/class II complexes and that the T cell response to each of these complexes can be modulated by the V alpha domain of the TCR. Interestingly, the recognition of SEA and SEE is achieved in different fashions by a given V beta20 T cell line.
Bravo de Alba
Y
Y
Département d'Immunologie, Institut Pasteur (URA CNRS 1961 and Université Pierre et Marie Curie), Paris, France. ybravo@pasteur.fr
Marche
P N
PN
Cazenave
P A
PA
Cloutier
I
I
Sekaly
R P
RP
Thibodeau
J
J
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology* / Q000378:metabolism; D015798:HLA-DR1 Antigen / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D011485:Protein Binding; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
D004768:Enterotoxins; D015798:HLA-DR1 Antigen; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011994:Recombinant Proteins; C049463:enterotoxin E, Staphylococcal; C026066:enterotoxin A, Staphylococcal