biostudies-literatureKatagiri WKeio UniversityNational Institute of Neurological Disorders and StrokeNational Institute of Allergy and Infectious DiseasesMassachusetts General HospitalNIAID NIH HHSKeidanrenNINDS NIH HHSTerumoe22521https://www.ebi.ac.uk/biostudies/studies/S-EPMC9574655biostudies-literatureUnknown36(10)Immunotherapy, including immune checkpoint inhibitors, has revolutionized cancer treatment, but only a minor fraction of patients shows durable responses. A new approach to overcome this limitation is yet to be identified. Recently, we have shown that photobiomodulation (PBM) with near-infrared (NIR) light in the NIR-II window reduces oxidative stress and supports the proliferation of CD8⁺ T cells, suggesting that PBM with NIR-II light could augment anti-cancer immunity. Here, we report a novel approach to support tumor-infiltrating CD8⁺ T cells upon PBM with NIR-II laser with high tissue penetration depth. Brief treatments of a murine model of breast cancer with dual 1064 and 1270 nm lasers reduced the expression of the programmed cell death protein 1 (PD-1) in CD8<sFASEB journal : official publication of the Federation of American Societies for Experimental BiologyDual near-infrared II laser modulates the cellular redox state of T cells and augments the efficacy of cancer immunotherapy.PMC9574655R01 NS096237R01NS096237R21AI144103R01AI105131R01 AI105131R21 AI144103Iwasaki TMonaco HAtochin DNKatagiri WSato AOgawa EFeil SRoessing MManganiello SChoi HSFukuda TFukumura DKashiwagi SKopp TNg MRYokomizo SIshizuka TYamashita KSato HNomura SfalseDual near-infrared II laser modulates the cellular redox state of T cells and augments the efficacy of cancer immunotherapy.Immunotherapy, including immune checkpoint inhibitors, has revolutionized cancer treatment, but only a minor fraction of patients shows durable responses. A new approach to overcome this limitation is yet to be identified. Recently, we have shown that photobiomodulation (PBM) with near-infrared (NIR) light in the NIR-II window reduces oxidative stress and supports the proliferation of CD8⁺ T cells, suggesting that PBM with NIR-II light could augment anti-cancer immunity. Here, we report a novel approach to support tumor-infiltrating CD8⁺ T cells upon PBM with NIR-II laser with high tissue penetration depth. Brief treatments of a murine model of breast cancer with dual 1064 and 1270 nm lasers reduced the expression of the programmed cell death protein 1 (PD-1) in CD8<s2022-01-01T00:00:00Z2022 Oct2025-04-25T21:27:51.973Z2025-04-06T08:44:21.256ZS-EPMC95746553605274210.1096/fj.202200033R10.1096/fj.202200033r