Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells Alleviated the Inflammatory Response in Mice Infected with the Influenza Virus A (H1N1).

Influenza A virus (H1N1) infection poses a significant global public health challenge and imposes a substantial economic burden. Numerous studies have shown that excessive immune activation and dysregulated inflammatory responses following influenza virus infection are the primary causes of disease progression and mortality. Extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) exhibit potent anti-inflammatory effects. Therefore, this study aims to investigate the effects of extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUCMSC-EVs) on pulmonary inflammatory responses in mice infected with the influenza A virus (H1N1). The study first established a mouse influenza virus infection model by intranasal inoculation of the influenza A virus (H1N1), followed by treatment with hUCMSC-EVs (70 μg) administered via tail vein injection for four consecutive days. The results showed that compared with the H1N1 group, after treatment with hUCMSC-EVs, pulmonary edema was reduced, inflammatory cell infiltration in the lungs was significantly decreased, and the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) proteins in serum and lung tissue were significantly reduced. Therefore, this study suggests that the protective effect of hUCMSC-EVs against lung damage caused by influenza A virus (H1N1) infection may be related to the reduction in inflammatory cytokine levels of TNF-α, IL-1β, and IL-6, thereby alleviating pulmonary inflammation.