Kosmides et al. developed “immunoswitch” nanoparticles that are coated with two different antibodies - one that activates CD8+ T cells via the 4-1BB co-stimulatory pathway, and another that blocks the inhibitory ligand PD-L1 on tumor cells. The presence of both binding moieties on each particle enhanced tumor antigen-specific T cell infiltration and functionality, as well as TCR diversity.
We describe the development of a nanoparticle platform that overcomes the immunosuppressive tumor microenvironment. These nanoparticles are coated with two different antibodies that simultaneously block the inhibitory checkpoint PD-L1 signal and stimulate T cells via the 4-1BB co-stimulatory pathway. These "immunoswitch" particles significantly delay tumor growth and extend survival in multiple in vivo models of murine melanoma and colon cancer in comparison to the use of soluble antibodies or nanoparticles separately conjugated with the inhibitory and stimulating antibodies. Immunoswitch particles enhance effector-target cell conjugation and bypass the requirement for a priori knowledge of tumor antigens. The use of the immunoswitch nanoparticles resulted in an increased density, specificity, and in vivo functionality of tumor-infiltrating CD8+ T cells. Changes in the T cell receptor repertoire against a single tumor antigen indicate immunoswitch particles expand an effective set of T cell clones. Our data show the potential of a signal-switching approach to cancer immunotherapy that simultaneously targets two stages of the cancer immunity cycle resulting in robust antitumor activity.
Author Info: (1) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopki
Author Info: (1) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopkins University School of Medicine , Baltimore, Maryland 21231, United States. (2) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopkins University School of Medicine , Baltimore, Maryland 21231, United States. (3) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopkins University School of Medicine , Baltimore, Maryland 21231, United States. (4) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopkins University School of Medicine , Baltimore, Maryland 21231, United States. (5) Department of Biomedical Engineering, double daggerInstitute for Nanobiotechnology, section signInstitute for Cell Engineering, and parallelDepartment of Pathology, Johns Hopkins University School of Medicine , Baltimore, Maryland 21231, United States.
