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.