Peritoneal M2 macrophage-derived extracellular vesicles as natural multi-target nanotherapeutics to attenuate cytokine storm after severe infections

Cytokine storm is a primary cause for multiple organ damage and death after severe infections, such as SARS-CoV-2. However, current single cytokine-targeted strategies display limited therapeutic efficacy. Here, we report that peritoneal M2 macrophages-derived extracellular vesicles (M2-EVs) are multi-target nanotherapeutics to resolve cytokine storm. In detail, primary peritoneal M2 macrophages exhibited superior anti-inflammatory potential than immobilized cell lines. Systemically administrated M2-EVs entered major organs and were taken up by phagocytes (e.g., macrophages). M2-EVs treatment effectively reduced excessive cytokine (e.g., TNF- and IL-6) release in vitro and in vivo, thereby attenuated oxidative stress and multiple organ (lung, liver, spleen and kidney) damage in endotoxin-induced cytokine storm. Moreover, M2-EVs simultaneously inhibited multiple key proinflammatory pathways (e.g., NF-{kappa}B, JAK-STAT and p38 MAPK) by regulating complex miRNA-gene and gene-gene networks, and this effect was collectively mediated by many functional cargos (miRNAs and proteins) in EVs. In addition to the direct anti-inflammatory role, human peritoneal M2-EVs expressed angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2 spike protein, and thus could serve as nanodecoys to prevent SARS-CoV-2 pseudovirus infection in vitro. As cell-derived nanomaterials, the therapeutic index of M2-EVs can be further improved by genetic/chemical modification or loading with specific drugs. This study highlights that peritoneal M2-EVs are promising multifunctional nanotherapeutics to attenuate infectious diseases-related cytokine storm.