High affinity of interaction between superantigen and T cell receptor Vbeta molecules induces a high level and prolonged expansion of superantigen-reactive CD4+ T cells.
In mice implanted with an osmotic pump filled with the superantigen (SAG) staphylococcal enterotoxin A (SEA), the Vβ3(+)CD4(+) T cells exhibited a high level of expansion whereas the Vβ11(+)CD4(+) T cells exhibited a mild level of expansion. In contrast, in mice implanted with an osmotic pump filled with SE-like type P (SElP, 78.1% homologous with SEA), the Vβ11(+)CD4(+) T cells exhibited a high level of expansion while the Vβ3(+)CD4(+) T cells exhibited a low level of expansion, suggesting that the level of the SAG-induced response is determined by the affinities between the TCR Vβ molecules and SAG. Analyses using several hybrids of SEA and SElP showed that residue 206 of SEA determines the response levels of Vβ3(+)CD4(+) and Vβ11(+)CD4(+) T cells both in vitro and in vivo. Analyses using the above-mentioned hybrids showed that the binding affinities between SEA and the Vβ3/Vβ11 β chains and between SEA-MHC class II-molecule complex and Vβ3(+)/Vβ11(+) CD4(+) T cells determines the response levels of the SAG-reactive T cells both in vitro and in vivo.
Omoe
Katsuhiko
K
Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate 020-8550, Japan.
Nunomura
Wataru
W
Kato
Hidehito
H
Li
Zhong-Juan
ZJ
Igarashi
Osamu
O
Araake
Minako
M
Sano
Keigo
K
Ono
Hisaya K
HK
Abe
Yohei
Y
Hu
Dong-Liang
DL
Nakane
Akio
A
Kiyono
Hiroshi
H
Takakuwa
Yuichi
Y
Shinagawa
Kunihiro
K
Uchiyama
Takehiko
T
Imanishi
Ken'ichi
K
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D018089:Superantigens / Q000235:genetics / Q000276:immunology*
D004768:Enterotoxins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011993:Recombinant Fusion Proteins; C504429:SEIP protein, Staphylococcus aureus; D018089:Superantigens; C026066:enterotoxin A, Staphylococcal