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Rahaman MH, Thygesen SJ, Maxwell MJ, Kim H, Mudai P, Nanson JD, Jia X, Vajjhala PR, Hedger A, Vetter I, Haselhorst T, Robertson AAB, Dymock B, Ve T, Mobli M, Stacey KJ, Kobe B. o-Vanillin binds covalently to MAL/TIRAP Lys-210 but independently inhibits TLR2. J Enzyme Inhib Med Chem 2024; 39:2313055. [PMID: 38416868 PMCID: PMC10903754 DOI: 10.1080/14756366.2024.2313055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 01/28/2024] [Indexed: 03/01/2024] Open
Abstract
Toll-like receptor (TLR) innate immunity signalling protects against pathogens, but excessive or prolonged signalling contributes to a range of inflammatory conditions. Structural information on the TLR cytoplasmic TIR (Toll/interleukin-1 receptor) domains and the downstream adaptor proteins can help us develop inhibitors targeting this pathway. The small molecule o-vanillin has previously been reported as an inhibitor of TLR2 signalling. To study its mechanism of action, we tested its binding to the TIR domain of the TLR adaptor MAL/TIRAP (MALTIR). We show that o-vanillin binds to MALTIR and inhibits its higher-order assembly in vitro. Using NMR approaches, we show that o-vanillin forms a covalent bond with lysine 210 of MAL. We confirm in mouse and human cells that o-vanillin inhibits TLR2 but not TLR4 signalling, independently of MAL, suggesting it may covalently modify TLR2 signalling complexes directly. Reactive aldehyde-containing small molecules such as o-vanillin may target multiple proteins in the cell.
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Affiliation(s)
- Md. Habibur Rahaman
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Sara J. Thygesen
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Michael J. Maxwell
- Centre for Advanced Imaging, University of Queensland, Brisbane, Australia
| | - Hyoyoung Kim
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Prerna Mudai
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Jeffrey D. Nanson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Xinying Jia
- Centre for Advanced Imaging, University of Queensland, Brisbane, Australia
| | - Parimala R. Vajjhala
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Andrew Hedger
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
- School of Pharmacy, University of Queensland, Brisbane, Australia
| | | | - Avril A. B. Robertson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Brian Dymock
- Queensland Emory Drug Discovery Initiative, University of Queensland, Brisbane, Australia
| | - Thomas Ve
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Mehdi Mobli
- Centre for Advanced Imaging, University of Queensland, Brisbane, Australia
| | - Katryn J. Stacey
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
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Nelson NLJ, Zajd CM, Lennartz MR, Gosselin EJ. Fcγ receptors and toll-like receptor 9 synergize to drive immune complex-induced dendritic cell maturation. Cell Immunol 2019; 345:103962. [PMID: 31582169 DOI: 10.1016/j.cellimm.2019.103962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/30/2019] [Accepted: 08/03/2019] [Indexed: 12/11/2022]
Abstract
Previous in vivo studies established that inactivated Francisella tularensis immune complexes (mAb-iFt) are a more protective vaccine against lethal tularemia than iFt alone. Subsequent in vitro studies revealed enhanced DC maturation marker expression with mAb-iFt stimulation. The goal of this study was to determine the mechanism of enhanced DC maturation. Multiparameter analysis of surface marker expression and cytokine secretion demonstrates a requirement for FcγR signaling in enhanced DC maturation. MyD88 was also found to be essential for heightened DC maturation, implicating MyD88-dependent TLRs in DC maturation. Upon further study, we discovered that TLRs 2 & 4 drive cytokine secretion, but surprisingly TLR9 is required for DC maturation marker upregulation. These studies reveal a separation of DC cytokine and maturation marker induction pathways and demonstrate that FcγR-TLR/MyD88 synergy underlies the enhanced dendritic cell maturation in response to the mAb-iFt vaccine.
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Affiliation(s)
- Nicole L J Nelson
- Department of Immunology and Microbial Disease, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, United States.
| | - Cheryl M Zajd
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, United States
| | - Michelle R Lennartz
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, United States
| | - Edmund J Gosselin
- Department of Immunology and Microbial Disease, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, United States.
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