Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors

IntroductionB7-H6, a tumor-specific immune checkpoint molecule within the B7 family, represents a promising therapeutic target due to its selective overexpression in malignancies and negligible expression in normal tissues.MethodHere, we developed bispecific antibodies (BsAbs) targeting B7-H6 to red...

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Main Authors: Xuqian Ma, Huixia He, Yuankui Zhu, Dianbao Zuo, FangLin Wang, Mingqian Feng, Kangkang Ji, Xin Chen
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Immunology
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Online Access:https://www.frontiersin.org/articles/10.3389/fimmu.2025.1625813/full
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author Xuqian Ma
Xuqian Ma
Huixia He
Yuankui Zhu
Dianbao Zuo
Dianbao Zuo
FangLin Wang
Mingqian Feng
Mingqian Feng
Kangkang Ji
Kangkang Ji
Xin Chen
Xin Chen
author_facet Xuqian Ma
Xuqian Ma
Huixia He
Yuankui Zhu
Dianbao Zuo
Dianbao Zuo
FangLin Wang
Mingqian Feng
Mingqian Feng
Kangkang Ji
Kangkang Ji
Xin Chen
Xin Chen
author_sort Xuqian Ma
collection DOAJ
description IntroductionB7-H6, a tumor-specific immune checkpoint molecule within the B7 family, represents a promising therapeutic target due to its selective overexpression in malignancies and negligible expression in normal tissues.MethodHere, we developed bispecific antibodies (BsAbs) targeting B7-H6 to redirect T and NK cells against solid tumors. Through phage display, 15 high-affinity B7-H6 monoclonal antibodies were generated.ResultsTwo optimized BsAbs, B7-H6M4-OKT3 (T cell-engaging) and B7-H6M4-LC21 (NK cell-engaging), were constructed in and scFv-hFc-scFv format. Both demonstrated nanomolar affinity (EC50: 0.04–1.22 nM) and selective cytotoxicity against B7-H6+ cells (H446, Huh-7, HepG2), while showing minimal cytotoxicity against B7-H6-negative cells (A431). B7-H6M4LC21 exhibited enhanced tumor-killing efficacy (IC50: 5 ng/mL) compared to B7H6M4-OKT3(IC50: 1 ng/mL) when combined with an IL-15/IL-15Ra sushi fusion protein, which augmented NK cell proliferation and cytotoxicity. In H446 xenograft models, both BsAbs suppressed tumor growth in a dose-dependent manner (0.1–20 mg/kg) without significant toxicity. Combination therapy with B7-H6M4-LC21 (10 mg/kg) and B7-H6M18/IL-15/IL-15Ra sushi (0.03 mg/kg) achieved synergistic tumor inhibition (p<0.05), surpassing the efficacy of T cell-based combinations.DiscussionThese findings establish B7-H6-targeted BsAbs combined with cytokine engineering as a viable strategy for treating refractory solid tumors.
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series Frontiers in Immunology
spelling doaj-art-54f4b33ee32b4e73bd4fa938b6236ce92025-08-20T03:36:06ZengFrontiers Media S.A.Frontiers in Immunology1664-32242025-08-011610.3389/fimmu.2025.16258131625813Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumorsXuqian Ma0Xuqian Ma1Huixia He2Yuankui Zhu3Dianbao Zuo4Dianbao Zuo5FangLin Wang6Mingqian Feng7Mingqian Feng8Kangkang Ji9Kangkang Ji10Xin Chen11Xin Chen12College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Biomedicine and Health, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Biomedicine and Health, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Biomedicine and Health, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, ChinaResearch Center for Translational Medicine, Xiangyang No.1 People’s Hospital, Hubei University of Medicine, Xiangyang, ChinaCollege of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Biomedicine and Health, Huazhong Agricultural University, Wuhan, Hubei, ChinaCollege of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, ChinaDepartment of Clinical Medical Research, Binhai County People’s Hospital, Clinical Medical College of Yangzhou University, Yancheng, Jiangsu, ChinaCollege of Biomedicine and Health, Huazhong Agricultural University, Wuhan, Hubei, ChinaSchool of Life and Health Sciences, Hubei University of Technology, Wuhan, Hubei, ChinaIntroductionB7-H6, a tumor-specific immune checkpoint molecule within the B7 family, represents a promising therapeutic target due to its selective overexpression in malignancies and negligible expression in normal tissues.MethodHere, we developed bispecific antibodies (BsAbs) targeting B7-H6 to redirect T and NK cells against solid tumors. Through phage display, 15 high-affinity B7-H6 monoclonal antibodies were generated.ResultsTwo optimized BsAbs, B7-H6M4-OKT3 (T cell-engaging) and B7-H6M4-LC21 (NK cell-engaging), were constructed in and scFv-hFc-scFv format. Both demonstrated nanomolar affinity (EC50: 0.04–1.22 nM) and selective cytotoxicity against B7-H6+ cells (H446, Huh-7, HepG2), while showing minimal cytotoxicity against B7-H6-negative cells (A431). B7-H6M4LC21 exhibited enhanced tumor-killing efficacy (IC50: 5 ng/mL) compared to B7H6M4-OKT3(IC50: 1 ng/mL) when combined with an IL-15/IL-15Ra sushi fusion protein, which augmented NK cell proliferation and cytotoxicity. In H446 xenograft models, both BsAbs suppressed tumor growth in a dose-dependent manner (0.1–20 mg/kg) without significant toxicity. Combination therapy with B7-H6M4-LC21 (10 mg/kg) and B7-H6M18/IL-15/IL-15Ra sushi (0.03 mg/kg) achieved synergistic tumor inhibition (p<0.05), surpassing the efficacy of T cell-based combinations.DiscussionThese findings establish B7-H6-targeted BsAbs combined with cytokine engineering as a viable strategy for treating refractory solid tumors.https://www.frontiersin.org/articles/10.3389/fimmu.2025.1625813/fullB7-H6bispecific antibodiesNK cellsIL-15Rα sushisolid tumor
spellingShingle Xuqian Ma
Xuqian Ma
Huixia He
Yuankui Zhu
Dianbao Zuo
Dianbao Zuo
FangLin Wang
Mingqian Feng
Mingqian Feng
Kangkang Ji
Kangkang Ji
Xin Chen
Xin Chen
Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
Frontiers in Immunology
B7-H6
bispecific antibodies
NK cells
IL-15Rα sushi
solid tumor
title Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
title_full Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
title_fullStr Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
title_full_unstemmed Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
title_short Dual T/NK cell engagement via B7-H6-targeted bispecific antibodies and IL-15 eradicates chemo-resistant solid tumors
title_sort dual t nk cell engagement via b7 h6 targeted bispecific antibodies and il 15 eradicates chemo resistant solid tumors
topic B7-H6
bispecific antibodies
NK cells
IL-15Rα sushi
solid tumor
url https://www.frontiersin.org/articles/10.3389/fimmu.2025.1625813/full
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