Superantigens anergize cytokine production but not cytotoxicity in vivo

• Published in: Immunology 1994-05, Vol.82 (1), p.117-125
• Main Authors: SUNDSTEDT, A, DOHLSTEN, M, HEDLUND, G, HÖIDEN, I, BJÖRKLUND, M, KALLAND, T
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; CD4-Positive T-Lymphocytes - immunology; CD8 Antigens - analysis; Clonal Anergy - immunology; Cytokines - biosynthesis; Cytotoxicity, Immunologic - immunology; Drug Administration Schedule; Enterotoxins - administration & dosage; Enterotoxins - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Immunobiology; Interferon Inducers - administration & dosage; Interferon Inducers - immunology; Mice; Mice, Transgenic; Modulation of the immune response (stimulation, suppression); Polymerase Chain Reaction; Spleen - immunology; Superantigens - administration & dosage; Superantigens - immunology; T-Lymphocyte Subsets - immunology
• ISSN: 0019-2805; 1365-2567

We have investigated the effect of the superantigen staphylococcal enterotoxin A (SEA) on the balance between T-cell response and non-responsiveness in T-cell receptor (TcR) V beta 3 transgenic mice. One injection of SEA resulted in a substantial activation of TcR V beta 3+ cells, whereas T cells from mice injected with repeated doses 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 V beta 3+ 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 V beta 3+ 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 tumour necrosis factor (TNF) were mainly produced by CD4+ T cells, while interferon-gamma (IFN-gamma) 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-gamma 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-gamma production and cytotoxicity in the CD8+ T-cell compartment stay relatively intact.