Lactylation of PD-L1 by a lactyltransferase HAT1 dictates its protein stability and tumor immune evasion

M Man Shang (Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)) X Xujie Zhao (Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University) Y Yibi Zhang (School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China) C Chang Zhang X Xiaohui Yang (Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)) Y Ya Wen (MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Anti-Infective Drug Discovery and Development, Guangdong Basic Research Center of Excellence for Functional Molecular Engineering, School of Chemistry) X Xiaofeng Zhu Y Yiwen Chen Y Yinmin Gu (Zhongda Hospital, Medical School, Advanced Institute for Life and Health, Southeast University) Y Yongbo Pan (Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University) S Siyuan Jiang (Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University) S Shuguang Tan (Innovative Vaccine and Immunotherapy Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine) X Xuemei Jia (Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)) C Chenbo Ji (Nanjing Medical Key Laboratory of Female Fertility Preservation and Restoration) S Shan Gao

Abstract

Lysine lactylation regulates protein fate and function across diverse biological processes. While PD-L1 has been widely studied posttranslationally, the role of its lactylation and the responsible enzyme have remained poorly studied. Here, we identify histone acetyltransferase 1 (HAT1) as a lactyltransferase that catalyzes programmed cell death ligand 1 (PD-L1) lactylation at residues K75 and K178 within its extracellular domain, thereby enhancing PD-L1 stability. Mechanistically, this glycosylation-dependent modification protects PD-L1 from endoplasmic reticulum (ER)-associated degradation and promotes ER-to-Golgi trafficking. Targeting PD-L1 lactylation by HAT1 knockdown, mutation of the lactylation sites or HAT1-PD-L1-interferring peptides suppresses tumor progression and enhances anti-PD-1 therapy efficacy. Clinically, lactylated PD-L1 strongly correlates with tumor progression. Together, these findings establish HAT1-mediated PD-L1 lactylation as a key mechanism of immune evasion and suggest that targeting this pathway could improve cancer immunotherapy outcomes.

Article Details

Volume / Issue Vol. 123, Issue 22
Published June 02, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (15)

M

Man Shang

Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)

X

Xujie Zhao

Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University

Y

Yibi Zhang

School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China

C

Chang Zhang

X

Xiaohui Yang

Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)

Y

Ya Wen

MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Anti-Infective Drug Discovery and Development, Guangdong Basic Research Center of Excellence for Functional Molecular Engineering, School of Chemistry

X

Xiaofeng Zhu

Y

Yiwen Chen

Y

Yinmin Gu

Zhongda Hospital, Medical School, Advanced Institute for Life and Health, Southeast University

Y

Yongbo Pan

Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University

S

Siyuan Jiang

Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Southeast University

S

Shuguang Tan

Innovative Vaccine and Immunotherapy Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine

X

Xuemei Jia

Department of Gynecology, Women’s Hospital of Nanjing Medical University (Nanjing Women and Children’s Healthcare Hospital)

C

Chenbo Ji

Nanjing Medical Key Laboratory of Female Fertility Preservation and Restoration

S

Shan Gao