Therapy of murine mammary carcinoma metastasis with interferon γ and MHC gene-transduced tumour cells

Abstract

Summary Gene-transfected tumour cells were used to cure mice bearing lung metastases by the parental, nontransduced mammary adenocarcinoma (TSA-pc). Repeated subcutaneous (s.c.) administrations of mitomycin C (MitC)-treated interferon y (IFN-y) transfectants induced a 90% inhibition in the number of lung metastases. Therapeutic effect required an intact T-cell response, as shown by the lack of efficacy in nude mice. Autocrine stimulation by IFN-y induces specific modifications in the phenotype of transfectants that acquire a high metastatic ability and show a high expression of IFN-responsive genes; these two features were exploited to design two experimental protocols to obtain an improvement of the therapeutic effect. The increased metastatic ability of IFN-y transfectants was used to deliver IFN-y selectively to the lungs of mice bearing TSA-pc pulmonary metastases. A significant therapeutic effect was obtained when TSA-pc experimental metastases were treated by repeated intravenous (i.v.) injections of MitC IFN-y transfectants. Since i.v. administrations of IFN-y transfectants did not induce immune memory, the therapeutical effect appeared to depend on the inflammatory-like response activated by local IFN release. To exploit the autocrine stimulation of IFNsensitive genes an IFN-y transfectant clone was subjected to a second transfection with an allogeneic class I MHC gene (H-2Kb or H-2Db). IFN-y plus MHC double transfectants maintained IFN-y release, showed a very high expression of the MHC gene products, stimulated both macrophages and T cells, and were less tumorigenic in immunocompetent mice than the parent IFN-y clone. Therapeutic efficacy of double transfectant IFN-y plus H-2Db cells against TSA-pc was superior to single transfectants, showing that the reaction elicited by genetically engineered cells can be selectively tuned to increase therapeutic efficacy.

The expression of CD70 and CD80 by gene-modified tumor cells induces an antitumor response depending on the MHC status

“…33 We did not test D d expression, as previous reports have shown that H -2D d TS /A expression levels are comparable with K d class I expression levels. 34 The B16.F10 subclone used in this study expresses low levels of H -2K b and H -2D b class I MHC molecules in vitro (Fig 1A ) . On the opposite, the B16K1 cells, which are a clone of B16.F10 cells which was transfected with H -2K b genes 31 express high levels of H -2K b (Fig 2D).…”

Immunity against breast cancer by TERT DNA vaccine primed with chemokine CCL21

“…26 B16 is a murine breast cancer cell line and 4T1 is a murine melanoma cancer cell. The cells were cultured in complete medium consisting of Rosewell Park Memorial Institute (RPMI) 1640, 10% heat-inactivated fetal bovine serum, 0.1 mM non-essential amino acids, 1 mM sodium pyruvate, 50 mM 2-Methoxy-1-ethanol (2-ME), 0.3% glutamine, 100 U/ml penicillin G sodium, 100 mg/ml streptomycin sulfate and 0.25 mg/ml amphotericin B (Life Technologies, Rockville, MD).…”

“…As adjuvants, IFN-g and GM-CSF have been shown to enhance tumor antigen-specific effects. 26,33 Enhanced production of IFN-g, GM-CSF and TNF-a are involved in tumor antigen-specific immunity. Prolonged and enhanced secretion of IFN-g by CD4 þ T cells may contribute to maintenance of an effective TERT-specific immune response and break immune tolerance.…”

“…We expected xenogeneic cTERT vaccine induced effective tumor antigen-specific immunity by breaking existing host immune tolerance. [22][23][24][25][26][27][28][29]33 However, xenogeneic cTERT vaccine alone could not induce effective tumor antigenspecific immunity and CCL21 administration was indispensable for effective tumor antigen-specific immunity. Prolonged and enhanced secretion of IFN-g by CD4 þ T cells may contribute to maintenance of an effective TERT-specific immune response.…”

“…25 We applied CCL21 as an adjuvant for TERT DNA vaccine against a TERT-expressing mouse breast cancer cell line (TS/A). 26 A DNA vaccine vector was constructed with cTERT fused with a ubiquitin sequence and a PAN DR T-helper epitope sequence (PADRE) to enhance protein presentation and the immunogenicity of cTERT, respectively. [27][28][29] Tumor antigen-specific immunity induced by TERT DNA vaccine was assessed by evaluating TERT-specific immunoglobulin (Ig)G response, delayed-type hypersensitivity (DTH), cytokine production and growth inhibition of the autologous TS/A breast tumor in Balb/c mice.…”