TY - JOUR

T1 - Inhibition of allostimulated HLA-DQ and DP-specific T cells by staphylococcal enterotoxin A

AU - Masewicz, S

AU - Ledbetter, J A

AU - Martin, P

AU - Mickelson, E

AU - Hansen, J A

AU - Odum, Niels

N1 - Keywords: Antigens, Bacterial; Bacterial Toxins; Enterotoxins; HLA-DP Antigens; HLA-DQ Antigens; Humans; Immune Tolerance; Isoantigens; Lymphocyte Activation; Receptors, Antigen, T-Cell, alpha-beta; Staphylococcus aureus; Superantigens; T-Lymphocyte Subsets

PY - 1993

Y1 - 1993

N2 - Bacterial superantigens have two immunologically important features. They bind MHC class II molecules and stimulate T cells bearing certain V beta TCR phenotypes. Superantigens such as SEA, SEB, and TSST bind to each of the three HLA class II isotypes (DR, DQ, and DP). Allotypic variation seems to play an important role in superantigen binding to class II molecules, but the functional implications of these differences remain largely unknown. In the present investigation, we studied the effects of SEA, SEB, and TSST on allostimulation of HLA-DR-, DQ-, and DP-allospecific T-cell clones. To avoid direct stimulation of T-cell responses by the superantigens, SEA and/or SEB nonresponsive T-cell clones were selected. We show that SEA strongly inhibited DQ- and DP-specific T-cell responses. In contrast, SEB and TSST had only weak inhibitory effects. DR-specific T-cell responses were unaffected or only weakly inhibited by the superantigens tested. The inhibition appeared not to be due to induction of cytotoxicity or suppression of either T cells or EBV-LCLs by SEA. In conclusion, the bacterial superantigen SEA can block alloantigen-specific stimulation of T clones in vitro. These results suggest that SEA binds to certain MHC class II molecules in a way that prevents MHC-TCR interactions.

AB - Bacterial superantigens have two immunologically important features. They bind MHC class II molecules and stimulate T cells bearing certain V beta TCR phenotypes. Superantigens such as SEA, SEB, and TSST bind to each of the three HLA class II isotypes (DR, DQ, and DP). Allotypic variation seems to play an important role in superantigen binding to class II molecules, but the functional implications of these differences remain largely unknown. In the present investigation, we studied the effects of SEA, SEB, and TSST on allostimulation of HLA-DR-, DQ-, and DP-allospecific T-cell clones. To avoid direct stimulation of T-cell responses by the superantigens, SEA and/or SEB nonresponsive T-cell clones were selected. We show that SEA strongly inhibited DQ- and DP-specific T-cell responses. In contrast, SEB and TSST had only weak inhibitory effects. DR-specific T-cell responses were unaffected or only weakly inhibited by the superantigens tested. The inhibition appeared not to be due to induction of cytotoxicity or suppression of either T cells or EBV-LCLs by SEA. In conclusion, the bacterial superantigen SEA can block alloantigen-specific stimulation of T clones in vitro. These results suggest that SEA binds to certain MHC class II molecules in a way that prevents MHC-TCR interactions.

M3 - Journal article

C2 - 8320132

VL - 36

SP - 142

EP - 148

JO - Human Immunology

JF - Human Immunology

SN - 0198-8859

IS - 3

ER -