Recombinaht gamma interferon and <em>in vivo</em> induction of HLA-DR antigens.

Recombinant human IFN-γ, used for treatment of melanoma and renal carcinoma, was found to induce HLA-DR expression on human keratinocytes in vivo. HLA-DR antigens bound to keratinocytes of the basal and suprabasal layers of the epidermis were observed after intramuscular or intravenous injections of 0·5 mg/kg body weight IFN-γ, 3 times a week. Keratinocyte-bound HLA-DR antigens were first observed at the beginning of the third or fourth week of treatment, but HLA-DQ and HLA-DP antigens were never detected on keratinocytes. The intracytoplasmic constant (γ) chain of the class II molecules was also not detectable within the keratinocytes. Patients who received IFN-α₂ therapy, did not exhibit keratinocyte-bound HLA-DR antigens. [ABSTRACT FROM AUTHOR]