Loss of interferon-gamma inducibility of the MHC class II antigen processing pathway in head and neck cancer: evidence for post-transcriptional as well as epigenetic regulation

Summary Background  Abnormalities of the major histocompatibility complex (MHC) antigens by tumour cells impair the cellular immune response and promote tumour evasion from immune surveillance. So far, studies analysing the MHC class II expression levels in head and neck cancer have been limited. Objectives  Therefore, we investigated the constitutive and interferon (IFN)-γ-regulated expression profiles of MHC class II antigen processing machinery (APM) in various head and neck cancer cell lines and also analysed the MHC class II expression in head and neck cancer lesions. Methods  Using immunohistochemistry, flow cytometry, and reverse transcriptase-polymerase chain reaction analyses we in…