CYTOKINE REGULATION OF MAJOR HISTOCOMPATIBILITY COMPLEX ANTIGEN EXPRESSION BY HUMAN ORAL AND SKIN KERATINOCYTES

The expression, and cytokine modulation, of major histocompatibility c omplex (MHC) class I and class II molecules on oral and skin keratinoc ytes were compared in cell culture. Both cell types expressed class I, but not class II, constitutively. However, stimulation with interfero n-gamma, but not interleukin-1 alpha, and -1 beta, tumour necrosis fac tor-alpha or lymphotoxin, induced increased expression of class I and de-novo expression of HLA-DR on both cell types. Oral keratinocytes di ffered from skin keratinocytes in that they exhibited greater sensitiv ity to interferon-gamma stimulation and higher stimulated expression o f both class I and HLA-DR. In addition, interferon-gamma stimulated or al, but not skin, keratinocytes to express HLA-DP and -DQ. These obser vations suggest that, like skin keratinocytes, under certain condition s, dial keratinocytes may be able to act as antigen-presenting cells. This may be important in the initiation and progression of some immune -mediated mucocutaneous diseases. Moreover, differences in MHC express ion may help to explain differences in the presentation of these disea ses on the skin and oral mucosa. Copyright (C) 1996 Elsevier Science L td.