title: Targeting ALCAM in the cryo-treated tumour microenvironment successfully induces systemic anti-tumour immunity.
abstract: Cryoablative treatment has been widely used for treating cancer. However, the therapeutic efficacies are still controversial. The molecular mechanisms of the cryo-induced immune responses, particularly underlying the ineffectiveness, remain to be fully elucidated. In this study, we identified a new molecular mechanism involved in the cryo failure. We used cryo-ineffective metastatic tumour models that murine melanoma B16-F10 cells were subcutaneously and intravenously implanted into C57BL/6 mice. When the subcutaneous tumours were treated cryoablation on day 7 after tumour implantation, cells expressing activated leucocyte cell adhesion molecule (ALCAM/CD166) were significantly expanded not only locally in the treated tumours but also systemically in spleen and bone marrow of the mice. The cryo-induced ALCAM(+) cells including CD45(-) mesenchymal stem/stromal cells, CD11b(+)Gr1(+) myeloid-derived suppressor cells, and CD4(+)Foxp3(+) regulatory T cells significantly suppressed interferon γ production and cytotoxicity of tumour-specific CD8(+) T cells via ALCAM expressed in these cells. This suggests that systemic expansion of the ALCAM(+) cells negatively switches host-immune directivity to the tumour-supportive mode. Intratumoural injection with anti-ALCAM blocking monoclonal antibody (mAb) following the cryo treatment systemically induced tumour-specific CD8(+) T cells with higher cytotoxic activities, resulting in suppression of tumour growth and metastasis in the cryo-resistant tumour models. These suggest that expansion of ALCAM(+) cells is a determinant of limiting the cryo efficacy. Further combination with an immune checkpoint inhibitor anti-CTLA4 mAb optimized the anti-tumour efficacy of the dual-combination therapy. Targeting ALCAM may be a promising strategy for overcoming the cryo ineffectiveness leading to the better practical use of cryoablation in clinical treatment of cancer.
authors.affiliation: Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Electronic address: kudoc@a3.keio.jp.
authors.forename: Chie
authors.initials: C
authors.lastname: Kudo-Saito
authors.affiliation: Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Fuwa
authors.affiliation: Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D020410:Activated-Leukocyte Cell Adhesion Molecule / Q000502:physiology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D015703:Antigens, CD; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015816:Cell Adhesion Molecules, Neuronal; D045744:Cell Line, Tumor; D003452:Cryosurgery / Q000379:methods*; D005326:Fetal Proteins; D005434:Flow Cytometry; D007371:Interferon-gamma / Q000378:metabolism; D008546:Melanoma, Experimental / Q000473:pathology / Q000601:surgery*; D051379:Mice; D008810:Mice, Inbred C57BL; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D059016:Tumor Microenvironment / Q000276:immunology*
chemical_list: C105613:ALCAM protein, human; D020410:Activated-Leukocyte Cell Adhesion Molecule; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015816:Cell Adhesion Molecules, Neuronal; D005326:Fetal Proteins; D007371:Interferon-gamma
keywords: ALCAM; Cryoablation; Immune checkpoint inhibitor; Immunosuppression; Mesenchymal stem cell