Reprogramming Exosomes for Immunotherapy.

Exosomes are nanosized vesicles secreted by nearly all types of cells and play important roles in intercellular communication. Given their unique and important pharmacological properties, exosomes have been emerging as a new class of cell-free therapeutics. Herein, we describe exosomes developed against epidermal growth factor receptor (EGFR), a key factor in epithelial malignancies, involved in enhanced tumor growth, invasion, and metastasis. The exosomes are genetically modified for displaying two distinct types of monoclonal antibodies on the exosome surface, resulting in novel synthetic multivalent antibodies retargeted exosomes (SMART-Exos) that can simultaneously target tumor-associated human EGFR and T-cell surface CD3 receptor. By redirecting and activating T cells toward attacking EGFR-expressing cancer cells, the designed SMART-Exos exhibit highly potent and specific antitumor activity. In this chapter, the methodologies are outlined for generating and using SMART-Exos for cancer immunotherapy.