Anti-IL2 monoclonal antibody, clone KFT7-6I5 [Biotin]

Purpose: Immunotherapy promises unprecedented benefits to patients with cancer. However, the majority of cancer types, including high-risk neuroblastoma, remain immunologically unresponsive. High-intensity focused ultrasound (HIFU) is a noninvasive technique that can mechanically fractionate tumors, transforming immunologically "cold'' tumors into responsive "hot'' tumors. Experimental Design: We treated < 2% of tumor volume in previously unresponsive, large, refractory murine neuroblastoma tumors with mechanical HIFU and assessed systemic immune response using flow cytometry, ELISA, and gene sequencing. In addition, we combined this treatment with alpha CTLA-4 and alpha PD-L1 to study its effect on the immune response and long-term survival. Results: Combining HIFU with alpha CTLA-4 and alpha PD-L1 significantly enhances antitumor response, improving survival from 0% to 62.5%. HIFU alone causes upregulation of splenic and lymph node NK cells and circulating IL2, IFN gamma, and DAMPs, whereas immune regulators like CD4(+) Foxp3(+), IL10, and VEGF-A are significantly reduced. HIFU combined with checkpoint inhibitors induced significant increases in intratumoral CD4(+), CD8 alpha(+), and CD8 alpha(+) CD11c(+) cells, CD11c(+) in regional lymph nodes, and decrease in circulating IL10 compared with untreated group. We also report significant abscopal effect following unilateral treatment of mice with large, established bilateral tumors using HIFU and checkpoint inhibitors compared with tumors treated with HIFU or checkpoint inhibitors alone (61.1% survival, P < 0.0001). This combination treatment significantly also induces CD4(+)CD44(+hi)CD62L(+low) and CD8 alpha(+)CD44(+hi)CD62L(+low) population and is adoptively transferable, imparting immunity, slowing subsequent de novo tumor engraftment. Conclusions: Mechanical fractionation of tumors using HIFU can effectively induce immune sensitization in a previously unresponsive murine neuroblastoma model and promises a novel yet efficacious immunoadjuvant modality to overcome therapeutic resistance.

The aetiology of inflammatory myopathies is not clearly known. A predominance of activated Cd8+ T lymphocytes in inflammatory infiltrates has already been detected. Superantigens activate lymphocytes in an oligoclonal manner. In the present investigation, we investigated local effects after injection of the superantigen (Sag) Staphylococcus enterotoxin A (SEA) in the quadriceps femoris muscle of Lewis rats. Histopathology and gene expression profiling was performed after injection of SEA or saline (control group) after one, three and 10days. Histology revealed focal myositis predominated by Cd8+ T lymphocytes with a perimysial, endomysial and perivascular distribution, peaking 3days after SEA injection. Using DNA microarray analysis (Affymetrix Rat Genome 230 2.0) genes that were differentially over-expressed at least 15 times at days one, three or ten after SEA injection were further analysed. One day after SEA injection over-expressed genes were related to the immune response (e.g. Fcnb, CD8a) but also to cell proliferation, differentiation and migration (e.g. Mpp2). Three days after SEA injection, differentially overexpressed genes were mainly related to the immune reaction with a clear signature for a Cd8+ T lymphocyte response (e.g. Cd3d, Cd8, Prf1, Gzmb). Ten days after SEA injection, the differentially overexpressed genes were again associated with the immune reaction (e.g. Cd3d, Il2) but also with regenerative processes and wound healing (e.g. Tgfa, Tpm1, Ripply1). The inflammatory response induced by SEA in Lewis rats shares histological and molecular similarities to polymyositis in humans. Therefore, SEA induced myositis can be taken as a new and apt model for polymyositis.