|
||
J. Exp. Med.,
Volume 189, Number 5, March 1, 1999 779-786
By



From the * Institut National de la Santé et de la Recherche Médicale (INSERM) U503, Faculté
Laennec, F-69372 Lyon Cedex 08, France; Contact hypersensitivity (CHS) is a T cell-mediated skin inflammation induced by epicutaneous exposure to haptens in sensitized individuals. We have previously reported that CHS to
dinitrofluorobenzene in mice is mediated by major histocompatibility complex (MHC) class
I-restricted CD8+ T cells. In this study, we show that CD8+ T cells mediate the skin inflammation through their cytotoxic activity. The contribution of specific cytotoxic T lymphocytes (CTLs) to the CHS reaction was examined both in vivo and in vitro, using mice deficient in
perforin and/or Fas/Fas ligand (FasL) pathways involved in cytotoxicity. Mice double deficient
in perforin and FasL were able to develop hapten-specific CD8+ T cells in the lymphoid organs but did not show CHS reaction. However, they did not generate hapten-specific CTLs,
demonstrating that the CHS reaction is dependent on cytotoxic activity. In contrast, Fas-deficient lpr mice, FasL-deficient gld mice, and perforin-deficient mice developed a normal CHS
reaction and were able to generate hapten-specific CTLs, suggesting that CHS requires either
the Fas/FasL or the perforin pathway. This was confirmed by in vitro studies showing that the
hapten-specific CTL activity was exclusively mediated by MHC class I-restricted CD8+ T cells
which could use either the perforin or the Fas/FasL pathway for their lytic activity. Thus, cytotoxic CD8+ T cells, commonly implicated in the host defence against tumors and viral infections, could also mediate harmful delayed-type hypersensitivity reactions.
INSERM U404, F-69365 Lyon Cedex 07, France;
the § Institute of Biochemistry, University of Lausanne, CH-1066 Epalinges, France; the
Ontario
Cancer Institute, Toronto, Ontario M5G 2M9, Canada; and the ¶ Department of Clinical
Immunology, Centre Hospitalier Lyon-Sud, F-69495 Pierre-Benite, France
This article has been cited by other articles:
| TABLE OF CONTENTS |
|