Zeaxanthin augments CD8+ effector T cell function and immunotherapy efficacy
- Cell Rep Med. 2025 Sep 16;6(9):102324. doi: 10.1016/j.xcrm.2025.102324.
- 1. Department of Medicine, The University of Chicago, Chicago, IL 60637, USA.
- 2. Department of Obstetrics & Gynecology, The University of Chicago, Chicago, IL 60637, USA.
- 3. Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA.
- 4. Health Science, DePaul University, Chicago, IL 60614, USA.
- 5. Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA.
- 6. Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA.
- 7. University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
- 8. Department of Systems Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA.
- 9. Department of Medicine, The University of Chicago, Chicago, IL 60637, USA. Electronic address: [email protected].
- 10. Department of Medicine, The University of Chicago, Chicago, IL 60637, USA. Electronic address: [email protected].
The detailed mechanisms underlying the regulatory significance of dietary components in modulating anti-tumor immunity remain largely unknown. Here, we apply a co-culture-based screening approach using a blood nutrient compound library and identify zeaxanthin (ZEA), a dietary carotenoid pigment found in many fruits and vegetables and known for its role in eye health, as an immunomodulator that enhances the cytotoxicity of CD8+ T cells against tumor cells. Oral supplementation with ZEA, but not its structural isomer lutein (LUT), enhances anti-tumor immunity in vivo. Integrated multi-omics mechanistic studies reveal that ZEA promotes T cell receptor (TCR) stimulation on the CD8+ T cell surface, leading to improved intracellular TCR signaling for effector T cell function. Hence, ZEA treatment augments the efficacy of anti-PD1 immune checkpoint inhibitor in vivo and the cytotoxicity of human TCR gene-engineered CD8+ T cells in vitro. Our findings uncover a previously unknown immunoregulatory function of ZEA, which has translational potential as a dietary element in bolstering immunotherapy.