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Lipid Nanoparticle-Mediated Delivery of miRNA Mimics to Myeloid Cells
Elaine Kang1, Marcin Kortylewski2
1Department of Immuno-Oncology; Beckman Research Institute at City of Hope, Duarte, CA, USA.
Abstract:
MicroRNA (miRNA) dysregulation is known to be associated with a variety of human diseases, including cancers and immune disorders. MiR146a represents one of the best characterized regulators of the immune response, as well as cellular survival through the negative feedback inhibition of nuclear factor-kappa B (NF-ĸB) signaling in myeloid cells. Restoration of miR146a levels would be an attractive therapeutic strategy for reducing exaggerated immune responses or to prevent certain types of blood cancers. However, delivery of synthetic miRNA mimics to target myeloid cells remains challenging. Here, we describe an optimized lipid nanoparticle (LNP) strategy for the delivery of miRNA mimics to myeloid immune cells and provide detailed protocols for characterization of LNP complexes and their biological activity. The encapsulation of miR146a within a lipid complex protects the nucleic acid from nuclease degradation, while allowing for rapid uptake by target myeloid immune cells. The strategy results in an efficient inhibition of target interleukin (IL) 1 receptor associated kinase 1 (IRAK1) and tumor necrosis factor receptor associated factor 6 (TRAF6) protein expression, thereby resulting in reduced NF-ĸB activity in mouse macrophages in vitro. The LNP-encapsulated miR146a effectively inhibits expression of IL-6, a major proinflammatory mediator downstream from NF-ĸB. This LNP-based strategy is suitable for testing of other miRNAs or RNA therapeutics targeting myeloid immune cells.
Insights
Researchers developed a lipid nanoparticle (LNP) delivery system for microRNA mimics, specifically miR146a, to target myeloid immune cells. This strategy effectively reduces inflammation and shows promise for treating immune disorders and blood cancers.
Area of Science:
- Immunology
- Molecular Biology
- Nanotechnology
Background:
- MicroRNA (miRNA) dysregulation is linked to diseases like cancer and immune disorders.
- MiR146a is a key regulator of immune response and cell survival by inhibiting nuclear factor-kappa B (NF-ĸB) signaling.
- Restoring miR146a levels offers a therapeutic approach for immune overactivity and certain blood cancers, but delivery remains a challenge.
Purpose of the Study:
- To develop and optimize a lipid nanoparticle (LNP) delivery system for miRNA mimics targeting myeloid immune cells.
- To characterize the LNP complexes and evaluate their biological activity in vitro.
- To demonstrate the potential of LNP-encapsulated miR146a as a therapeutic strategy for immune modulation.
Main Methods:
- Encapsulation of synthetic miR146a mimics within optimized lipid nanoparticles (LNPs).
- Characterization of LNP complexes for stability and miRNA protection.
- In vitro assessment of LNP-mediated delivery and biological activity in mouse macrophages.
- Quantification of target protein and cytokine expression (IRAK1, TRAF6, IL-6) and NF-ĸB activity.
Main Results:
- LNPs effectively encapsulate and protect miR146a from degradation.
- Rapid uptake of LNP-miR146a by target myeloid immune cells was observed.
- Efficient inhibition of IRAK1 and TRAF6 protein expression, leading to reduced NF-ĸB activity.
- Significant reduction in the pro-inflammatory mediator IL-6 expression.
Conclusions:
- An optimized LNP strategy enables effective delivery of miRNA mimics to myeloid immune cells.
- LNP-encapsulated miR146a successfully modulates immune responses by inhibiting NF-ĸB signaling.
- This LNP-based platform is adaptable for delivering other RNA therapeutics to myeloid cells for various disease applications.
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