Engineered extracellular vesicles for TGF-β encapsulation as a therapeutic strategy against LPS-induced systemic...

Inflammation underlies a wide variety of physiological and pathological processes, the Lipopolysaccharide (LPS)-induced inflammation model is widely recognized as a classical inflammatory paradigm, while Transforming growth factor-β (TGF-β) serves as a potent immunosuppressant capable of inhibiting immune responses and mitigating inflammation. However, its in vivo instability and the high cost associated with purification have imposed limitations on its clinical application. Therefore, we propose a therapeutic strategy for genetically modifying extracellular vesicles (HEVs) derived from HEK-293 T cells to incorporate TGF-β which holds potential for mitigating LPS-induced inflammation. In this study, we engineered a TGF-β lentivirus that specific incorporates TGF-β into HEVs and efficiently produces highly expressed TGF-β HEVs (HEVTs) through infection of HEK293 cells. Our data demonstrated that, compared to the LPS group, HEVTs internalized by immune cells significantly regulated pro-inflammatory cytokine expression in RAW 264.7 cells, such as IL-1β (p < 01), TNF-α (p < 001). Moreover, HEVTs were found to effectively reach the lesion area, compared to the LPS group, resulting in a remarkable inhibition in the activation of macrophages (p < 0.0001), dendritic cells (p < 0.0001), and neutrophils (p < 0.0001) in the peripheral immune system as well as microglia in the central nervous system of LPS-induced inflammation model mice. The utilization of this endogenous loading technique may present a promising strategy for the protein-based pharmacotherapy of inflammatory disorders.