Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4

Abstract Ionizable lipid nanoparticles (LNP) that have enabled the success of messenger RNA (mRNA) vaccines have been shown to be immunostimulatory in the absence of mRNA. However, the mechanisms through which they activate innate immune cells is incompletely understood. Using a monocyte cell line,...

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Main Authors: Amanda E. Zelkoski, Zhongyan Lu, Gauthaman Sukumar, Clifton Dalgard, Hooda Said, Mohamad-Gabriel Alameh, Edward Mitre, Allison M. W. Malloy
Format: Article
Language:English
Published: Nature Portfolio 2025-04-01
Series:npj Vaccines
Online Access:https://doi.org/10.1038/s41541-025-01124-x
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author Amanda E. Zelkoski
Zhongyan Lu
Gauthaman Sukumar
Clifton Dalgard
Hooda Said
Mohamad-Gabriel Alameh
Edward Mitre
Allison M. W. Malloy
author_facet Amanda E. Zelkoski
Zhongyan Lu
Gauthaman Sukumar
Clifton Dalgard
Hooda Said
Mohamad-Gabriel Alameh
Edward Mitre
Allison M. W. Malloy
author_sort Amanda E. Zelkoski
collection DOAJ
description Abstract Ionizable lipid nanoparticles (LNP) that have enabled the success of messenger RNA (mRNA) vaccines have been shown to be immunostimulatory in the absence of mRNA. However, the mechanisms through which they activate innate immune cells is incompletely understood. Using a monocyte cell line, we compared the ability of three LNP formulations to activate transcription factors Nuclear Factor-kappa B (NF-κB) and Interferon Regulatory Factor (IRF). Comparison of signaling in knockout cell lines illustrated a role for Toll-like receptor (TLR) 4 in initiation of this signaling cascade and the contribution of the ionizable lipid component. Activation induced by empty LNPs was similar to that induced by LNPs containing mRNA, indicating that LNPs may provide the majority of innate stimulation for the mRNA vaccine platform. Our findings demonstrate that ionizable lipids within LNPs signal through TLR4 to activate NF-κB and IRF, identifying a mechanism for innate activation that can be optimized for adjuvant design.
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issn 2059-0105
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publishDate 2025-04-01
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series npj Vaccines
spelling doaj-art-e112d4deddbc4f26b0ee6e982f0bc5d32025-08-20T03:18:53ZengNature Portfolionpj Vaccines2059-01052025-04-0110111310.1038/s41541-025-01124-xIonizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4Amanda E. Zelkoski0Zhongyan Lu1Gauthaman Sukumar2Clifton Dalgard3Hooda Said4Mohamad-Gabriel Alameh5Edward Mitre6Allison M. W. Malloy7Department of Pediatrics, Uniformed Services University of Health SciencesDepartment of Pediatrics, Uniformed Services University of Health SciencesHenry M Jackson Foundation for the Advancement of Military MedicineDepartment of Anatomy, Physiology & Genetics, Uniformed Services University of Health SciencesDepartment of Pathology and Laboratory Medicine, Children’s Hospital of PhiladelphiaDepartment of Pathology and Laboratory Medicine, Children’s Hospital of PhiladelphiaDepartment of Microbiology and Immunology, Uniformed Services University of Health SciencesDepartment of Pediatrics, Uniformed Services University of Health SciencesAbstract Ionizable lipid nanoparticles (LNP) that have enabled the success of messenger RNA (mRNA) vaccines have been shown to be immunostimulatory in the absence of mRNA. However, the mechanisms through which they activate innate immune cells is incompletely understood. Using a monocyte cell line, we compared the ability of three LNP formulations to activate transcription factors Nuclear Factor-kappa B (NF-κB) and Interferon Regulatory Factor (IRF). Comparison of signaling in knockout cell lines illustrated a role for Toll-like receptor (TLR) 4 in initiation of this signaling cascade and the contribution of the ionizable lipid component. Activation induced by empty LNPs was similar to that induced by LNPs containing mRNA, indicating that LNPs may provide the majority of innate stimulation for the mRNA vaccine platform. Our findings demonstrate that ionizable lipids within LNPs signal through TLR4 to activate NF-κB and IRF, identifying a mechanism for innate activation that can be optimized for adjuvant design.https://doi.org/10.1038/s41541-025-01124-x
spellingShingle Amanda E. Zelkoski
Zhongyan Lu
Gauthaman Sukumar
Clifton Dalgard
Hooda Said
Mohamad-Gabriel Alameh
Edward Mitre
Allison M. W. Malloy
Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
npj Vaccines
title Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
title_full Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
title_fullStr Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
title_full_unstemmed Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
title_short Ionizable lipid nanoparticles of mRNA vaccines elicit NF-κB and IRF responses through toll-like receptor 4
title_sort ionizable lipid nanoparticles of mrna vaccines elicit nf κb and irf responses through toll like receptor 4
url https://doi.org/10.1038/s41541-025-01124-x
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