ABSTRACT
Expression of major histocompatibility complex antigens by epithelial cells may play a role in the aetiology of autoimmune disorders. We have studied the effect of γ-interferon on SGHTL-34, a human thyroid cell line which constitutively expresses class I but not class II antigens. γ-Interferon induced the expression of class II and increased the expression of class I molecules (assessed by flow cytofluorimetry) in a dose-dependent manner. Thyrotrophin or phytohaemagglutinin had no effect on either class I or class II expression. However, a supernatant from phytohaemagglutinin-stimulated peripheral blood mononuclear cells, containing 6400 U γ-interferon/ml, was an effective inducer of both class I and class II antigens. These data clarify earlier studies using primary thyroid cultures, which are contaminated with cells of the immune system.
Inhibitor (IK) of IFN-γ induced HLA class II antigens expression also inhibits HLA class II constitutive expression in the human Raji B cell line