Induction of the synthesis of triton-soluble proteins in human keratinocytes by gamma interferon.

Recombinant human gamma interferon (r-IFN-gamma) induces the synthesis and expression of HLA-DR antigen on cultured, normal, human keratinocytes depleted of Langerhans cells. After removal of r-IFN-gamma from the culture medium of keratinocytes that are expressing HLA-DR antigen, the cells continue to express this antigen for at least 2 days. r-IFN-gamma induces, in a dose dependent fashion, the synthesis of several triton-soluble proteins with the most prominent having an apparent molecular weight of 53,000. Whereas normal keratinocytes do not express HLA-DR antigen in vivo, they do express HLA-DR in a variety of skin diseases such as lichen planus, graft-versus-host disease, and mycosis fungoides. We propose that an understanding of lymphocyte-keratinocyte interactions in vivo may be achieved by further studies of the mechanism of action of r-IFN-gamma on cultured keratinocytes and that the results may provide insight into the patho-physiology leading to a number of common inflammatory and neoplastic skin diseases.

Liposome-mediated gene transfer into human basal cell carcinoma.

Direct intralesional injection of DNA encoding interferon-alpha2 (IFN-alpha2) was used in an effort to sustain local protein delivery for the treatment of human basal cell carcinoma (BCC). A novel model to study this malignancy was established by transplantation of human BCC tissue on to immunodeficient mice with a relatively high rate of engraftment and stable phenotype for superficial BCC (20 of 25; 80%). Gene transfer was significantly increased by using DNA liposome complexes (lipoplexes). Recombinant gene expression was detected predominantly in the epidermis and, to a lesser extent, in the dermis. Gene transfer of IFN-alpha2 using this method resulted in sustained production of IFN-alpha2 protein and increased expression of a known IFN-inducible gene, the class II major histocompatibility (MHC) antigen, and induced BCC regression, presumably through a non-immune mechanism. Intralesional injection of DNA lipoplexes encoding IFN-alpha protein may therefore be applicable to the treatment of cutaneous BCC.

Immune response in human melanoma after transfer of an allogeneic class I major histocompatibility complex gene with DNA-liposome complexes.

Analysis of the antitumor immune response after gene transfer of a foreign major histocompatibility complex class I protein, HLA-B7, was performed. Ten HLA-B7-negative patients with stage IV melanoma were treated in an effort to stimulate local tumor immunity. Plasmid DNA was detected within treated tumor nodules, and RNA encoding recombinant HLA-B7 or HLA-B7 protein was demonstrated in 9 of 10 patients. T cell migration into treated lesions was observed and tumor-infiltrating lymphocyte reactivity was enhanced in six of seven and two of two patients analyzed, respectively. In contrast, the frequency of cytotoxic T lymphocyte against autologous tumor in circulating peripheral blood lymphocytes was not altered significantly, suggesting that peripheral blood lymphocyte reactivity is not indicative of local tumor responsiveness. Local inhibition of tumor growth was detected after gene transfer in two patients, one of whom showed a partial remission. This patient subsequently received treatment with tumor-infiltrating lymphocytes derived from gene-modified tumor, with a complete regression of residual disease. Thus, gene transfer with DNA-liposome complexes encoding an allogeneic major histocompatibility complex protein stimulated local antitumor immune responses that facilitated the generation of effector cells for immunotherapy of cancer.