We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Superantigens anergize cytokine production but not cytotoxicity <em>in vivo</em>.
- Authors
Sundstedt, A.; Dohlsten, M.; Hedlund, G.; HÖidén, I.; Björklund, M.; Kalland, T.
- Abstract
We have investigated the effect of the superantigen staphylococcal enterotoxin A (SEA) on the balance between T-cell response and non-responsivess in T-cell receptor (TcR) Vβ3 transgenic mice. One injection of SEA resulted in a substantial activation of TcR Vβ3+ cells, whereas T cells from mice injected with repeated dosas of SEA displayed a diminished response to a subsequent in vitro challenge. The reduced responsiveness became apparent when SEA was injected multiple times with short intervals. Proliferation and cytokine production in anergized T cells were severely reduced when stimulated with SEA in vitro, whereas cytotoxic T lymphocyte (CTL) activity remained unaffected. The dichotomy between these functions was examined in vitro with respect to different T-cell subsets. The total number of CD4+ T cells was reduced in the hyporesponsive spleens, compatible with cell deletion. The remaining CD4+ TcR Vβ3+ T cells showed anergy of all tested functions and did not respond to exogenous interleukin-2 (IL-2). In contrast, there was an expansion of CD8+ TcR Vβ+ T cells with an intact cytotoxic activity. The in vitro proliferation and production of cytokines in the CD8+ compartment was impaired, but could be partially restored in the presence of exogenously added IL-2. Analysis of the cytokine response to SEA in vivo showed that IL-2 and turnout necrosis factor (TNF) were mainly produced by CD4+ T cells, while interferon-γ (IFN-+) was predominantly released by CD8+ T cells. Induction of anergy resulted in a reduction of IL-2 and TNF mRNA levels, frequencies of producing cells as well as serum protein content. In contrast, there was only a moderate influence on the IFN-γ level in vivo. The results suggest that SEA-induced hyporesponsiveness involves CD4+ cell deletion and a failure to produce cytokines in the remaining CD4+ T-cell compartment, while IFN-γ production and cytotoxicity in the CD8+ T-cell compartment stay relatively intact.
- Subjects
SUPERANTIGENS; CYTOKINES; TRANSGENIC mice; T cell receptors; INTERFERONS; INTERLEUKIN-2; VIRAL antigens; CELLULAR immunity
- Publication
Immunology, 1994, Vol 82, Issue 1, p117
- ISSN
0019-2805
- Publication type
Article