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 Printable version |
Cytokine deviation induced by intrathymic injection of staphylococcal enterotoxin B (SEB) |
European Cytokine Network. Volume 12, Number 3, 487-500, September 2001, Articles originaux
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 Free Article
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Author(s) : P. Goettelfinger, F. Lecerf, S. Berrih-Aknin, M. German-Fattal |
Summary : We have previously shown that intrathymic (i.t.) injection of staphylococcal enterotoxin B (SEB) to mice induces both T cell clonal deletion and IL-2-dependent anergy. In the present study, we have used a quantitative RT-PCR to demonstrate that i.t. administration of SEB induced a significant decrease in the levels of the IL-2 and IFN-gamma mRNAs in total splenocytes, from day 7 to day 28 post-injection. I.t. SEB injection also induced a significant increase in the levels both of IL-10 and TGF-beta mRNAs on day 7, leading to a significant enhance in the IL-10 + TGF-beta/IL-2 + IFN-gamma mRNA ratio on days 7 and 28. By contrast, IL-10 and TGF-beta mRNAs were unchanged after intraperitoneal (i.p.) or subcutaneous (s.c.) SEB injections, although both IL-2 and IFN-gamma mRNA levels were decreased. The cytokine mRNA ratio was enhanced on days 7 and 28 after i.p. injection. Interestingly, a cytokine mRNA ratio of a least 10 in favour of IL-10 plus TGF-beta mRNAs was correlated with the hyporesponsive state observed in vitro after i.t. and i.p. injections.
Our results clearly demonstrate that i.t. SEB administration induces a switch from Th1-type to Th2-type cytokine expression in the spleen. The deviation from IL-2 plus IFN-gamma towards IL-10 plus TGF-beta expression could be responsible for the immunoregulatory effect exerted upon SEB-reactive T cells, which is characterized by an IL-2-dependent, specific anergy in vitro. Moreover, it highlights the crucial role of the route of SEB injection in the pattern of cytokine expression. |
Keywords : SEB, intrathymic injection, anergy, cytokine deviation, quantitative RT-PCR. |
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