In vivo effects of interferon-γ and anti-interferon-γ antibody on the experimentally induced lichenoid tissue reaction

Abstract

We investigated the in vivo effect of recombinant interferon-gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) treatment of mice on the development of the delayed-type hypersensitivity (DTH) reaction and lichenoid tissue reaction (LTR) following the local injection of cloned autoreactive T cells. Both the DTH reaction and the LTR were significantly enhanced by pretreatment with IFN-gamma, but not with TNF-alpha. Induction of class II MHC antigens on keratinocytes was not essential for the enhancement by IFN-gamma. Administration of anti-IFN-gamma antibody reduced the DTH reaction and LTR, although complete inhibition was not observed with our treatment regimen. The ability of IFN-gamma to increase the number of the cloned T cells invading the epidermis in vivo, is in keeping with our previous observation that IFN-gamma treatment of cultured keratinocytes markedly increased the adherence reaction between T cells and keratinocytes in vitro.