Role of interleukin-2 in superantigen-induced T-cell anergy.
T-cell anergy is a state of immunological tolerance characterized by unresponsiveness to antigenic stimulation. Previous studies have shown that anergy is induced in T cells following stimulation in the absence of adequate costimulatory signals. These cells fail to respond to stimulation via the T-cell receptor (TCR), and fail to produce normal levels of interleukin-2 (IL-2). We present results here which show that low concentrations of the superantigen staphylococcal enterotoxin A (SEA) in the absence of antigen-presenting cells induced both proliferation and anergy in the A.E7 T-cell clone. Furthermore, under these conditions, the A.E7 clone remained responsive to exogenous IL-2. Fluorescence-activated cellular cytometry analysis revealed unaltered expression of the TCR/CD3 complex in the anergized clone; however, both CD4 and CD25 expression increased after 24 hr of stimulation by SEA under these conditions. Interestingly, a low level of IL-2 production was measured during the induction of anergy. Most strikingly, stimulation of the A.E7 clone by SEA in combination with exogenous IL-2 resulted in a more pronounced state of anergy. These results suggest that the induction of anergy is a process that is essentially independent of the production of IL-2.
Cornwell
W D
WD
Department of Microbiology and Immunology, Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA, USA.
Rogers
T J
TJ
D000818:Animals; D015704:CD4 Antigens / Q000378:metabolism; D002460:Cell Line; D017635:Clonal Anergy; D002999:Clone Cells; D004768:Enterotoxins / Q000494:pharmacology*; D005434:Flow Cytometry; D007369:Interferon Inducers / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology / Q000502:physiology*; D051379:Mice; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013211:Staphylococcus aureus / Q000276:immunology; D018089:Superantigens / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D015704:CD4 Antigens; D004768:Enterotoxins; D007369:Interferon Inducers; D007376:Interleukin-2; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D018089:Superantigens; C026066:enterotoxin A, Staphylococcal