Abstract
Dendritic cells (DCs), which are typical antigen-presenting cells, localize to various sites in the body, particularly the front line of infection as sentinels, and are involved in innate and adaptive immune responses. Although the functions of DCs, such as pathogen-induced cytokine production and antigen-specific T cell activation, are important for host defenses against infection and tumorigenesis, the hyper- and/or extended activation of DCs leads to inflammatory and autoimmune diseases. In the present study, β-damascone, a major ingredient of rose fragrance, was selected from an aroma library as a candidate compound that suppresses antigen-induced immune responses. β-Damascone inhibited the functions of DCs, including the antigen-dependent proliferation of T cells, DC-induced Th1 development, and the TLR ligand-induced production of inflammatory cytokines by DCs. The β-damascone treatment also increased the protein level of the transcription factor NRF2, which plays key roles in antioxidant responses, and the transcription of Hmox1, a target gene of NRF2, in DCs. Nrf2−/− DCs induced Th1-development and produced large amount of IL-12p40 even in the presence of β-damascone, whereas these functions by Nrf2+/− DCs were inhibited by β-damascone under the same conditions. The intake of β-damascone suppressed ear swelling in contact hypersensitivity (CHS) model mice, but not in CHS-induced Nrf2−/− mice. Collectively, the present results indicate the potential of the rose aroma compound β-damascone, which suppresses DC-mediated immune responses by activating the NRF2 pathway in DCs, for the prevention and/or attenuation of immune-mediated diseases.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Funding: This work was supported by a Grant-in-Aid for Scientific Research (B) 20H02939 (CN); Grants-in-Aid for Scientific Research (C) 21K05297 (MH), 19K05884 (TY), and 19K08920 (KK); a Research Fellowship for Young Scientists DC2 and a Grant-in-Aid for JSPS Fellows 21J12113 (KN); a Scholarship for Doctoral Student in Immunology (from JSI to NI); a Tokyo University of Science Grant for President’s Research Promotion (CN); the Tojuro Iijima Foundation for Food Science and Technology (CN); a Research Grant from the Mishima Kaiun Memorial Foundation (CN); and a Research Grant from the Takeda Science Foundation (CN).
author list updated; Figure 1 revised; Figure 2 revised; Figure 4 revised; Figure 5C added; manuscript revised; supplemental file updated.
- Abbreviations
- Ab
- antibody
- Ag
- antigen
- APCs
- antigen-presenting cells
- BMDCs
- bone marrow-derived dendritic cells
- CHS
- contact hypersensitivity
- DCs
- dendritic cells
- DNFB
- 2,3-dinitrofluorobenzene
- NRF2
- NF-E2-related factor 2
- OVA
- ovalbumin
- p.o.
- per os