Abstract: The presently disclosed subject matter relates to immunoswitch particles that switch off immunosuppressive pathways on tumor cells or immunosuppressive molecules induced by tumor cells in the tumor microenvironment, or virus infected cells or immunosuppressive molecules induced by virus infected cells in the microenvironment surrounding the virus infected cells, while simultaneously switching on co-stimulatory or co-inhibitory pathways on T cells, as well as method for converting immunosuppressive signals in cells, tissues, and subjects into stimulatory signals, and immunotherapy-based methods for treating cancer and chronic viral infections.

Abstract: The presently disclosed subject matter relates to immunoswitch particles that switch off immunosuppressive pathways on tumor cells or immunosuppressive molecules induced by tumor cells in the tumor microenvironment, or virus infected cells or immunosuppressive molecules induced by virus infected cells in the microenvironment surrounding the virus infected cells, while simultaneously switching on co-stimulatory or co-inhibitory pathways on T cells, as well as method for converting immunosuppressive signals in cells, tissues, and subjects into stimulatory signals, and immunotherapy-based methods for treating cancer and chronic viral infections.

Abstract: The present invention provides biodegradable, biomimetic particles for interacting with cells, including immune cells. In various embodiments, the particles comprise a polymer blend comprising a polyester, such as poly(lactic-co-glycolic acid) (PLGA) and a polyamine, such as poly(beta-amino ester) (PBAE). The particles further comprise, on their surface, one or more ligands for one or more cell surface receptor(s) or cell surface molecule(s). In some embodiments, the cell surface receptor or cell surface molecule is on an immune cell, such as a lymphocyte (T cell or B cell), natural killer cell, dendritic cell, or other cell of the immune system or tumor microenvironment.

Abstract: The presently disclosed subject matter relates to immunoswitch particles that switch off immunosuppressive pathways on tumor cells or immunosuppressive molecules induced by tumor cells in the tumor microenvironment, or virus infected cells or immunosuppressive molecules induced by virus infected cells in the microenvironment surrounding the virus infected cells, while simultaneously switching on co-stimulatory or co-inhibitory pathways on T cells, as well as method for converting immunosuppressive infections.