Effect of Treatments with Cyclosporin A and Anti‐Interferon‐γ Antibodies on the Mechanisms of Immune Tolerance in Staphylococcal Enterotoxin B Primed Mice

Abstract

Kuschnaroff LM, Valckx D, Goebels J, Rutgeerts O, Heremans H, Froyen G, Waer M. Effect of Treatments with Cyclosporin A and Anti-Interferon-g Antibodies on the Mechanisms of Immune Tolerance in Staphylococcal Enterotoxin B Primed Mice. Scand J Immunol 1997;46:459-468 The authors were interested to investigate the effect of Cyclosporin A (CsA), known to block interleukin-2 (IL-2) production, or of anti-interferon-g antibodies (anti-IFN-g Abs) in a model of T cell tolerance induced by the injection of the superantigen Staphylococcal Enterotoxin B (SEB) in BALB/c mice. After SEB immunization, tolerance was mainly achieved through deletion and anergy of SEB-reactive Vb8 þ T cells. Association of CsA treatment with SEB led to a greater decrease of the percentage of Vb8 þ CD4 þ lymphocytes in the spleen and an abolition of clonal anergy. In contrast, treatment of SEB primed mice with anti-IFN-g Abs resulted in an increased percentage of Vb8 þ CD4 þ cells without affecting the induction of clonal anergy. The authors found that 1-2 h after SEB priming, splenic mRNA levels of IFN-g and IL-4 were decreased by either CsA and anti-IFN-g Abs, whereas FasL, Bcl-2, p. 53, and c-myc levels were not influenced by either treatment. However, SEB-induced IL-2 and IL-10 mRNA expression was suppressed only by CsA, whereas tumour necrosis factor-a (TNF-a) was decreased only by anti-IFN-g Abs. To investigate whether the effect of CsA on the tolerance mechanisms was related to suppression of IL-2, CsA was administered together with recombinant IL-2. Whereas anergy was not influenced, the decreased percentage of Vb8 þ CD4 þ cells seen in CsA-treated animals in the second week after SEB injection was partially corrected by the administration of IL-2. Experiments involving bromodeoxiuridine incorporation revealed that the latter effect of IL-2 was mainly due to a correction of the defective proliferation of Vb8 þ T cells after SEB injection in CsA-treated mice. These results suggest that the effect of CsA and anti-IFN-g Abs on tolerance mechanisms are in part explained by their action on cytokines.

QUANTIFICATION OF MURINE CYTOKINE mRNAs USING REAL TIME QUANTITATIVE REVERSE TRANSCRIPTASE PCR

“…[4][5][6] One method measures PCR product accumulation during the exponential phase of the reaction. 7,8 To obtain semi-quantitative results it is extremely important that the PCR product is measured during the log phase of the reaction, thus before saturation is reached. This is the major difficulty using this method, because it necessitates interruption of the PCR reaction after an experimentally determined number of cycles.…”

“…For the detection of PCR products using either of these methods, several detection techniques can be used, all requiring excessive post-PCR manipulations. The most common used are agarose gel electrophoresis and EtBr-staining, 7 fluorescent labelling and analysis using polyacrylamide gels, 9 radioactive labelling and Southern blotting 8 or detection by phosphorimaging. 10 Major drawbacks using these classical detection systems are the use of hazardous chemicals and the From the 1 Laboratory for Experimental Transplantation and 2 potential risk for laboratory contamination.…”