The inhibition of cutaneous T cell apoptosis may prevent resolution of inflammation in atopic eczema

Clin Exp Immunol. 2000 Nov;122(2):150-6. doi: 10.1046/j.1365-2249.2000.01333.x.

Abstract

Atopic eczema (AE) is characterized by the persistence of infiltrating T lymphocytes in the dermis. To test the hypothesis that dysregulation of normal T cell apoptosis may contribute to the pathogenesis and chronicity of AE we compared patients with a normal resolving immune response (Mantoux reaction (MR)) induced in healthy volunteers by cutaneous PPD injection. Significantly less T cell apoptosis was observed in lesional skin of AE patients compared with either the peak or the resolution phase of the MR (P < 0.0001). The low incidence of T cell apoptosis in AE was associated with significantly increased levels of Bcl-2 relative to Bax (P < 0.0001) and significantly decreased CD95-L expression (P < 0.002) compared with the resolving MR. The cytokines IL-15 and interferon-beta (IFN-beta), which prevent activated T cell apoptosis, were expressed maximally on day 7 and day 14 of the MR, respectively. In contrast, AE patients expressed high levels of both IL-15 and IFN-beta in cutaneous lesions at the same time. This suggests that the co-expression of two anti-apoptotic cytokines, which are not found together during resolving cutaneous responses, may contribute to excessive T cell survival which leads to the persistence of inflammation in patients with AE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Apoptosis / immunology
  • Case-Control Studies
  • Cell Division
  • Dermatitis, Atopic / immunology
  • Dermatitis, Atopic / pathology*
  • Female
  • Humans
  • Interferon-beta / biosynthesis
  • Interleukin-15 / biosynthesis
  • Lymphocyte Activation
  • Skin / immunology
  • Skin / pathology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / pathology*
  • Tuberculin Test

Substances

  • Interleukin-15
  • Interferon-beta