Identification of α-galactosylceramide as an endogenous mammalian antigen for iNKT cells
Invariant natural killer T (iNKT) cells are unconventional T cells recognizing lipid antigens in a CD1d-restricted manner. Among these lipid antigens, α-galactosylceramide (α-GalCer), which was originally identified in marine sponges, is the most potent antigen. Although the presence of α-anomeric hexosylceramide and microbiota-derived branched α-GalCer is reported, antigenic α-GalCer has not been identified in mammals. Here, we developed a high-resolution separation and detection system, supercritical fluid chromatography tandem mass spectrometry (SFC/MS/MS), that can discriminate hexosylceramide diastereomers (α-GalCer, α-GlcCer, β-GalCer, or β-GlcCer). The B16 melanoma tumor cell line does not activate iNKT cells; however, ectopic expression of CD1d was sufficient to activate iNKT cells without adding antigens. B16 melanoma was unlikely to generate iNKT cell antigens; instead, antigen activity was detected in cell culture serum. Activity-based purification and SFC/MS/MS identified dihydrosphingosine-based saturated α-GalCer as an antigenic component in serum, bile, and lymphoid tissues. These results show the first evidence for the presence of potent antigenic α-GalCer in mammals.
Authors
- Atsushi Kumanogoh (ORCID: https://orcid.org/0000-0003-4749-7117)
- Masatomo Takahashi (ORCID: https://orcid.org/0000-0002-2493-2684)
- Yuki Hosono (ORCID: https://orcid.org/0000-0001-9993-6789)
- Federica Compostella (ORCID: https://orcid.org/0000-0003-4721-0358)
- Hiroshi Kida (ORCID: https://orcid.org/0000-0002-9351-7855)
- Noriyuki Tomiyasu (ORCID: https://orcid.org/0000-0003-4619-2805)
- Akihiro Imamura (ORCID: https://orcid.org/0000-0002-7860-992X)
- Takeshi Bamba (ORCID: https://orcid.org/0000-0002-7442-2738)
- Hayato Kasai
- Hideharu Ishida (ORCID: https://orcid.org/0000-0002-8625-0929)
- Yoshihiro Izumi (ORCID: https://orcid.org/0000-0003-4608-4652)
- Sho Yamasaki (ORCID: https://orcid.org/0000-0002-5184-6917)
- Eri Ishikawa (ORCID: https://orcid.org/0000-0002-4922-6751)
Institutions
- Kyushu University (JP)
- University of Milan (IT)
- Life Systems (United States) (US)
- Toneyama National Hospital (JP)
- National Hospital Organization (JP)
- Gifu University (JP)
- Osaka International University (JP)
- The University of Osaka (JP)
Publication Details
- Journal
- The Journal of Experimental Medicine
- Published
- 2024-12-20
- DOI
- https://doi.org/10.1084/jem.20240728
- Citations
- 10
- Primary Topic
- Immune Cell Function and Interaction
- Type
- article
- Field-Weighted Citation Impact
- 2.40
Funders
- Japan Agency for Medical Research and Development
- Ministry of Education, Culture, Sports, Science and Technology
- Osaka University
- Japan Society for the Promotion of Science