Use of focused ultrasound to increase melanoma immunogenicity and inhibit tumor-induced T cell tolerance

Immunosuppressive mechanisms in the tumor microenvironment promote tumor growth by preventing the adaptive immune system from mounting effective antitumor responses. One of the main consequences of the immunosuppressive tumor microenvironment is the induction of tumor antigen-specific T cell tolerance. Overcoming such blockade has remained a major challenge in cancer immunotherapy. Our data show that thermic and physical stress induced by low-intensity focused ultrasound (LOFU) prevents the induction of tumor- antigen specific T cell tolerance and, in combination with ablative therapy, results in improved control of primary melanoma, reduces local recurrence and markedly decreases the occurrence of pulmonary metastases. This represents a new therapeutic approach that by acting locally on tumor cells has the potential to inhibit the establishment of tumor-antigen specific induced T cell tolerance. In this application, our goal is to understand the mechanisms that induce enhanced immunogenic melanoma cell death after LOFU-treatment, determine the potential of using LOFU+ablation as an in-situ melanoma vaccine and finally study whether LOFU can increase efficiency and reduced toxicity when used in combination with checkpoint inhibitors.