Melanoma cells treated with GGTI and IFN-gamma allow murine vaccination and enhance cytotoxic response against human melanoma cells.
BACKGROUND
Suboptimal activation of T lymphocytes by melanoma cells is often due to the defective expression of class I major histocompatibility antigens (MHC-I) and costimulatory molecules. We have previously shown that geranylgeranyl transferase inhibition (done with GGTI-298) stimulates anti-melanoma immune response through MHC-I and costimulatory molecule expression in the B16F10 murine model [1].


RESULTS
In this study, it is shown that vaccination with mIFN-gand GGTI-298 pretreated B16F10 cells induces a protection against untreated tumor growth and pulmonary metastases implantation. Furthermore, using a human melanoma model (LB1319-MEL), we demonstrated that in vitro treatment with hIFN-gamma and GGTI-298 led to the up regulation of MHC-I and a costimulatory molecule CD86 and down regulation of an inhibitory molecule PD-1L. Co-culture experiments with peripheral blood mononuclear cells (PBMC) revealed that modifications induced by hIFN-gamma and GGTI-298 on the selected melanoma cells, enables the stimulation of lymphocytes from HLA compatible healthy donors. Indeed, as compared with untreated melanoma cells, pretreatment with hIFN-gamma and GGTI-298 together rendered the melanoma cells more efficient at inducing the: i) activation of CD8 T lymphocytes (CD8+/CD69+); ii) proliferation of tumor-specific CD8 T cells (MelanA-MART1/TCR+); iii) secretion of hIFN-gamma; and iv) anti-melanoma specific cytotoxic cells.


CONCLUSIONS
These data indicate that pharmacological treatment of melanoma cell lines with IFN-gamma and GGTI-298 stimulates their immunogenicity and could be a novel approach to produce tumor cells suitable for vaccination and for stimulation of anti-melanoma effector cells.
Sarrabayrouse
Guillaume
G
Département Innovation thérapeutique et Oncologie Moléculaire, INSERM U563 CPTP, Toulouse, France.
Pich
Christine
C
Moriez
Raphaël
R
Armand-Labit
Virginie
V
Rochaix
Philippe
P
Favre
Gilles
G
Tilkin-Mariamé
Anne-Françoise
AF
D000818:Animals; D051940:B7-2 Antigen / Q000276:immunology / Q000378:metabolism; D001549:Benzamides / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D019169:Jurkat Cells; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008545:Melanoma / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008546:Melanoma, Experimental / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D014611:Vaccination / Q000379:methods*
D051940:B7-2 Antigen; D001549:Benzamides; D016207:Cytokines; C102521:GGTI 298; D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma