615 Reactivating antitumor immunity in gliomas with osteopontin/integrin blocking peptide by Bozena Kaminska, Paulina Pilanc-Kudlek, Katarzyna Poleszak, Aleksandra Ellert-Miklaszewska, Adria-Jaume Roura Canalda, Salwador Cyranowski, Julian Swatler, Bartłomiej Gielniewski