Researchers from the University of Osaka and other institutions announced on July 31 that a specially treated cell-derived product, called a SPLEV, demonstrated strong protection against the effects of cytokine storms in mice. The findings were published in Science Advances.
Cytokine storm is described as a runaway immune response that can be induced by infection, leading to severe systemic inflammation. This condition can cause respiratory failure, liver damage, abnormal blood clotting, and sometimes death. The COVID-19 pandemic highlighted the dangers of unchecked respiratory disease and brought increased attention to this phenomenon. Approaches to treating these symptoms remain unclear.
The research team generated sPLA2-reacted extracellular vesicles (SPLEVs) by treating liver cell extracellular vesicles with sPLA2. These SPLEVs were then injected into mice with acute respiratory distress syndrome to assess their effects.
"The results were very clear," said Ai Kotani, senior author. "We found that the SPLEVs strongly suppressed lung inflammation, as evidenced by the presence of fewer immune cells in the lungs and considerably lower levels of cytokine production."
The study noted that SPLEVs preferentially interacted with the lining of the lung rather than targeting macrophages like untreated extracellular vesicles. Further analysis indicated they acted directly on lung epithelial cells to trigger significant production of tissue-protective lipids.
"We coined the term 'lipid counterstorm' to describe this effect, as it successfully counters the effects of a cytokine storm induced by lung disease," said Nakayama.
According to researchers, SPLEVs also showed beneficial effects in mouse models for other inflammatory diseases such as sepsis, coagulopathy, liver injury, colitis, and pneumonia. They suggested that developing inexpensive cell-free artificial SPLEVs could become a valuable future therapeutic tool.
