A mouse model of human TLR4 D299G/T399I SNPs reveals mechanisms of altered LPS and pathogen responses

Authors

Katharina Richard, University of Maryland, School of Medicine
Kurt H. Piepenbrink, University of Nebraska - LincolnFollow
Kari Ann Shirey, University of Maryland, School of Medicine
Archana Gopalakrishnan, University of Maryland, School of Medicine
Shreeram Nallar, University of Maryland, School of Medicine
Daniel J. Prantner, University of Maryland, School of Medicine
Darren J. Perkins, University of Maryland, School of Medicine
Wendy Lai, University of Maryland, School of Medicine
Alexandra Vik, University of Maryland, School of Medicine
Vladimir Y. Toshchakov, University of Maryland, School of Medicine
Chiguang Feng, University of Maryland, School of Medicine
Rachel Fanaroff, University of Maryland Medical Center
Andrei E. Medvedev, University of Connecticut Health Center
Jorge C.G. Blanco, Sigmovir Biosystems, Inc., Rockville, MD
Stefanie N. Vogel, University of Maryland, School of MedicineFollow

ORCID IDs

Katharina Richard https://orcid.org/0000-0003-0939-2103

Kurt H. Piepenbrink https://orcid.org/0000-0002-2527-0301

Kari Ann Shirey https://orcid.org/0000-0002-6988-9720

Archana Gopalakrishnan https://orcid.org/0000-0001-6145-5146

Shreeram Nallar https://orcid.org/0000-0003-1812-7424

Daniel J. Prantner https://orcid.org/0000-0003-2180-043X

Darren J. Perkins https://orcid.org/0000-0003-1368-6366

Wendy Lai https://orcid.org/0000-0001-6288-2481

Alexandra Vlk https://orcid.org/0000-0003-1384-0669

Vladimir Y. Toshchakov https://orcid.org/0000-0002-7942-2294

Chiguang Feng https://orcid.org/0000-0002-2355-3607

Rachel Fanaroff https://orcid.org/0000-0002-7564-5597

Jorge C.G. Blanco https://orcid.org/0000-0002-6173-0213

Stefanie N. Vogel https://orcid.org/0000-0001-8244-2555

Document Type

Article

Date of this Version

2020

Citation

J. Exp. Med. 2020 Vol. 218 No. 2 e20200675

https://doi.org/10.1084/jem.20200675

Comments

© 2020 Richard et al. available under a Creative Commons License

Abstract

Two cosegregating single-nucleotide polymorphisms (SNPs) in human TLR4, an A896G transition at SNP rs4986790 (D299G) and a C1196T transition at SNP rs4986791 (T399I), have been associated with LPS hyporesponsiveness and differential susceptibility to many infectious or inflammatory diseases. However, many studies failed to confirm these associations, and transfection experiments resulted in conflicting conclusions about the impact of these SNPs on TLR4 signaling. Using advanced protein modeling from crystallographic data of human and murine TLR4, we identified homologous substitutions of these SNPs in murine Tlr4, engineered a knock-in strain expressing the D298G and N397I TLR4 SNPs homozygously, and characterized in vivo and in vitro responses to TLR4 ligands and infections in which TLR4 is implicated. Our data provide new insights into cellular and molecular mechanisms by which these SNPs decrease the TLR4 signaling efficiency and offer an experimental approach to confirm or refute human data possibly confounded by variables unrelated to the direct effects of the SNPs on TLR4 functionality.