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Published on: May 31, 2018
Cationic lipid/DNA complexes induce TNF-alpha secretion in splenic macrophages
Caroline Lonez1, Michel Vandenbranden, Abdelatif Elouahabi
1Université Libre de Bruxelles, Brussels, Belgium.
Summary
Cationic lipid/DNA complexes trigger inflammation. This study found that splenic macrophages are the primary source of tumor necrosis factor-alpha (TNF-alpha) secretion following intravenous injection of these complexes.
Area of Science:
- Biomedical Engineering
- Immunology
- Pharmacology
Background:
- Cationic lipids are essential for DNA delivery into mammalian cells.
- Lipid/DNA complexes can provoke inflammatory responses, limiting their therapeutic application.
- Understanding the source of inflammation is crucial for developing safer gene delivery systems.
Purpose of the Study:
- To pinpoint the organs and specific cell types responsible for TNF-alpha secretion after cationic lipid/DNA lipoplex administration.
- To elucidate the in vivo kinetics of lipoplex distribution and associated inflammatory markers.
Main Methods:
- Quantified lipoplex distribution in blood, lung, liver, and spleen over time.
- Measured TNF-alpha levels in organ homogenates and serum.
- Utilized spleen cell fractionation to identify cytokine-producing cells.
- Employed macrophage-depleting agents in vivo to confirm cell type involvement.
Main Results:
- Elevated TNF-alpha production was exclusively detected in the spleen, with no significant increase in other tested organs.
- Spleen cell analysis identified macrophages as the predominant source of TNF-alpha secretion.
- In vivo experiments corroborated that macrophages are responsible for the observed TNF-alpha increase.
Conclusions:
- Splenic macrophages are the main contributors to serum TNF-alpha elevation after intravenous lipoplex injection.
- This finding is critical for mitigating inflammatory side effects associated with cationic lipid-based gene delivery vectors.
- Targeting splenic macrophages could be a strategy to improve the safety profile of lipoplex-based therapies.
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