RESUMO
BACKGROUND: Kerationcytes make up the vast majority of cells within the epidermis. Recent attention has focused on the role keratinocytes may play in the induction of T cell mediated inflammatory responses in skin, particularily because keratinocytes, when activated by immunologic stimuli, express MHC class llAg and secrete cytokines. But in experimentally induced lichenoid tissue reaction by interferon-nu, MHC class ll Ag was not essential for the enhanced T cell trafficking. There is growing evidence that keratinocyte intercellular adhesion molecule-1 (ICAM-1) expression is involved in the epidermal trafficking of T lymphocytes. OBJECT: To investigate the kinetics of expression of the HLA-DR and ICAM-1 on cultured human keratinocytes by recombinant-interferon-nu(IFN) and phorbol myristate acetate(PMA), and the influence of the HLA-DR and ICAM-1 and the stimulation of peripheral blood mononuclear leukocytes(PBML). RESULTS: 1. 1 U/ml of IFN can induce HLA-DR and ICAM-1 on keratinocytes. Expression of both antigens were increased in a dose and exporsure time dependent fashion. But expression of HLA-DR was less sensitive to IFN than ICAM-1 2. ICAM-1 induction was more rapid than HLA-DR. Keratinocytes expressed HLA-DR 6hours after IFN treatment amd increased rapidly after 12 hours. 3. HLA-DR positive keratinocytes were decreased more rapidly that ICAM-1 positive kerationcytes. 4. Proliferations of PBML were slightly inhibited when cultured with keratinocytes which were treated or not treated with IFN. But IFN treated keratinocytes stimulated the PBML more than untreated keratinocytes. Proliferaton of PBML by IFN treated keratinocytes were inhibited by anti-ICAM monoclonal antibody 5. PMA treated keratinocytes stimulated the PBML more than untreated keratinocytes. Proliferation of PBML by PMA treated keratinocytes was inhibited by anti-ICAM monoclonal antibodies and anti-LFA-1 monoclonal antibodies. CONCLUSION: These results suggest that keratinocytes can express not only HLA-DR but also ICAMP1 may play a important role in initiating immunologic response. Complete clarification of the function of HLA-DR and ICAM-1 positive keratinocytes requires furthe5r study