Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1

Abstract Background The abundance of PD-L1 on the surface of tumor cells is a critical factor in sensitizing these cells to T cell-mediated immune killing. While abnormal glycosylation of PD-L1 is known to influence its expression and function, the precise regulatory mechanisms remain unclear. Metho...

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Main Authors: Xueting Ren, Jinpeng Wu, Jing Li, Zhen Zhai, Xiang Li, Feng Guan, Meng Wang, Xiaobin Ma, Zengqi Tan, Huafeng Kang, Shuai Lin
Format: Article
Language:English
Published: BMC 2025-08-01
Series:Experimental Hematology & Oncology
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Online Access:https://doi.org/10.1186/s40164-025-00693-w
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author Xueting Ren
Jinpeng Wu
Jing Li
Zhen Zhai
Xiang Li
Feng Guan
Meng Wang
Xiaobin Ma
Zengqi Tan
Huafeng Kang
Shuai Lin
author_facet Xueting Ren
Jinpeng Wu
Jing Li
Zhen Zhai
Xiang Li
Feng Guan
Meng Wang
Xiaobin Ma
Zengqi Tan
Huafeng Kang
Shuai Lin
author_sort Xueting Ren
collection DOAJ
description Abstract Background The abundance of PD-L1 on the surface of tumor cells is a critical factor in sensitizing these cells to T cell-mediated immune killing. While abnormal glycosylation of PD-L1 is known to influence its expression and function, the precise regulatory mechanisms remain unclear. Methods This study utilized bioinformatics analysis to explore the role of MGAT3, a key gene involved in the formation of the bisecting GlcNAc structure, in breast cancer (BC). Experimental approaches were employed to increase bisecting GlcNAc levels in BC cells, followed by assessments of PD-L1 expression, CD8+ T cell-mediated cytotoxicity, extracellular vesicle (EV)-associated PD-L1, and PD-L1/PD-1 interaction. Additionally, forskolin, a bisecting GlcNAc agonist, was combined with anti-PD-L1 antibody to evaluate its antitumor effects in vivo. Results MGAT3 was found to be expressed at low levels in BC tissues but positively correlated with CD8+ T cell infiltration. Elevating bisecting GlcNAc levels in BC cells significantly enhanced the cytotoxic efficacy of CD8+ T cells. High bisecting GlcNAc modification promoted PD-L1 degradation via the lysosomal pathway, reducing PD-L1 expression and its binding to PD-1. Furthermore, increased bisecting GlcNAc levels reduced PD-L1 in tumor cell-derived EVs, impairing the EVs’ ability to block CD8+ T cells and indirectly enhancing T cell cytotoxicity. The combined use of forskolin and anti-PD-L1 antibody significantly increased CD8+ T cell abundance and activity, achieving a more effective antitumor response in vivo. Conclusions These findings demonstrate that enhancing bisecting GlcNAc modification in BC cells promotes PD-L1 degradation and inhibits its binding to PD-1, thereby boosting CD8+ T cell-mediated cytotoxicity, providing a promising strategy for immune modulation in BC therapy.
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series Experimental Hematology & Oncology
spelling doaj-art-979428d086e0442093cc0ade3e53f1022025-08-20T03:42:40ZengBMCExperimental Hematology & Oncology2162-36192025-08-0114111710.1186/s40164-025-00693-wBisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1Xueting Ren0Jinpeng Wu1Jing Li2Zhen Zhai3Xiang Li4Feng Guan5Meng Wang6Xiaobin Ma7Zengqi Tan8Huafeng Kang9Shuai Lin10The Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityKey Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest UniversityKey Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest UniversityThe Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityKey Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest UniversityKey Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest UniversityThe Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityThe Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityInstitute of Hematology, Provincial Key Laboratory of Biotechnology, School of Medicine, Northwest UniversityThe Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityThe Comprehensive Breast Care Center, The Second Affiliated Hospital of Xi’an Jiaotong UniversityAbstract Background The abundance of PD-L1 on the surface of tumor cells is a critical factor in sensitizing these cells to T cell-mediated immune killing. While abnormal glycosylation of PD-L1 is known to influence its expression and function, the precise regulatory mechanisms remain unclear. Methods This study utilized bioinformatics analysis to explore the role of MGAT3, a key gene involved in the formation of the bisecting GlcNAc structure, in breast cancer (BC). Experimental approaches were employed to increase bisecting GlcNAc levels in BC cells, followed by assessments of PD-L1 expression, CD8+ T cell-mediated cytotoxicity, extracellular vesicle (EV)-associated PD-L1, and PD-L1/PD-1 interaction. Additionally, forskolin, a bisecting GlcNAc agonist, was combined with anti-PD-L1 antibody to evaluate its antitumor effects in vivo. Results MGAT3 was found to be expressed at low levels in BC tissues but positively correlated with CD8+ T cell infiltration. Elevating bisecting GlcNAc levels in BC cells significantly enhanced the cytotoxic efficacy of CD8+ T cells. High bisecting GlcNAc modification promoted PD-L1 degradation via the lysosomal pathway, reducing PD-L1 expression and its binding to PD-1. Furthermore, increased bisecting GlcNAc levels reduced PD-L1 in tumor cell-derived EVs, impairing the EVs’ ability to block CD8+ T cells and indirectly enhancing T cell cytotoxicity. The combined use of forskolin and anti-PD-L1 antibody significantly increased CD8+ T cell abundance and activity, achieving a more effective antitumor response in vivo. Conclusions These findings demonstrate that enhancing bisecting GlcNAc modification in BC cells promotes PD-L1 degradation and inhibits its binding to PD-1, thereby boosting CD8+ T cell-mediated cytotoxicity, providing a promising strategy for immune modulation in BC therapy.https://doi.org/10.1186/s40164-025-00693-wBreast cancerBisecting GlcNAcCD8+ T cellsPD-L1Immunotherapy
spellingShingle Xueting Ren
Jinpeng Wu
Jing Li
Zhen Zhai
Xiang Li
Feng Guan
Meng Wang
Xiaobin Ma
Zengqi Tan
Huafeng Kang
Shuai Lin
Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
Experimental Hematology & Oncology
Breast cancer
Bisecting GlcNAc
CD8+ T cells
PD-L1
Immunotherapy
title Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
title_full Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
title_fullStr Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
title_full_unstemmed Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
title_short Bisecting GlcNAc enhances CD8+ T cell-mediated killing of breast cancer by suppressing PD-L1 expression and its binding to PD-1
title_sort bisecting glcnac enhances cd8 t cell mediated killing of breast cancer by suppressing pd l1 expression and its binding to pd 1
topic Breast cancer
Bisecting GlcNAc
CD8+ T cells
PD-L1
Immunotherapy
url https://doi.org/10.1186/s40164-025-00693-w
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