Cell Squeeze: driving more effective CD8 T-cell activation through cytosolic antigen delivery

Cell Squeeze is a novel technology that relies on temporarily disrupting the cell membrane to deliver cargo directly into the cytosol. This approach is applicable to a broad range of cell types (peripheral blood mononuclear cells, red blood cells, hematopoietic stem cells, etc.) and cargos (peptides, proteins, small molecules, nucleic acids, and gene-editing complexes) while minimally disrupting normal cell function. By enabling direct cytosolic delivery, one can use this technology to dramatically enhance major histocompatibility complex (MHC) class I presentation of antigens (Ags) for CD8+ T-cell activation—a longstanding challenge for the therapeutic cancer vaccine field that has generally relied on cross-presentation of endocytosed Ags. In addition, by coupling improved MHC class I presentation with coexpression of additional stimulatory factors or systemic immune modulators, one can further enhance the potential impact of an antitumor CD8 response. Pursuing a more direct cellular engineering strategy, which is independent of viral transduction, genetic manipulation, and expansion steps, enables <24 h manufacturing of autologous cell therapies. Through generation of more sophisticated, multifunctional, cell-based vaccines, clinical testing of this technology will elucidate its potential for impact across multiple tumor types.