Induction of HLA-DR antigen on human squamous carcinoma by recombinant interferon gamma

The antigen recognition system which plays the major role in immunologic attraction mechanisms, including graft rejection, is the class II major histocompatibility complex containing the HLA-DR locus. Few types of cells constitutively express this antigen, as it is a potent immunological activating signal usually confined to antigen processing cells, activated lymphocytes, and endothelium. Using indirect immunofluorescence, we have observed induction of the HLA-DR glycoprotein in selected head and neck squamous cell carcinoma tissue cultures treated with recombinant interferon gamma. This occurs in concert with growth arrest and morphological changes after rHuIFN-gamma treatment. This report describes the induction of a surface antigen that may have profound prognostic significance. Understanding the kinetics of HLA-DR induction will aid in the design and assessment of adoptive immunotherapy with rHuIFN-gamma.