1. Academic Validation
  2. Fibrinogen-like Protein 1 Is a Major Immune Inhibitory Ligand of LAG-3

Fibrinogen-like Protein 1 Is a Major Immune Inhibitory Ligand of LAG-3

  • Cell. 2019 Jan 10;176(1-2):334-347.e12. doi: 10.1016/j.cell.2018.11.010.
Jun Wang 1 Miguel F Sanmamed 1 Ila Datar 2 Tina Tianjiao Su 1 Lan Ji 1 Jingwei Sun 1 Ling Chen 3 Yusheng Chen 4 Gefeng Zhu 1 Weiwei Yin 5 Linghua Zheng 1 Ting Zhou 1 Ti Badri 1 Sheng Yao 1 Shu Zhu 1 Agedi Boto 6 Mario Sznol 7 Ignacio Melero 8 Dario A A Vignali 9 Kurt Schalper 2 Lieping Chen 10
Affiliations

Affiliations

  • 1 Department of Immunobiology, Yale University, New Haven, CT 06511, USA.
  • 2 Department of Pathology, Yale University, New Haven, CT 06510, USA.
  • 3 Immunotherapy Institute, Fujian Medical University, Fuzhou, Fujian 350108, China.
  • 4 Provincial Clinical Medical College, Fujian Medical University, Fuzhou, Fujian 350108, China.
  • 5 Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
  • 6 Department of Immunobiology, Yale University, New Haven, CT 06511, USA; Department of Pathology, Yale University, New Haven, CT 06510, USA.
  • 7 Department of Medicine (Medical Oncology), Yale University, New Haven, CT 06510, USA.
  • 8 Department of Immunology and Immunotherapy, University of Navarra, Pamplona 31008, Spain.
  • 9 Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA 15232, USA.
  • 10 Department of Immunobiology, Yale University, New Haven, CT 06511, USA; Immunotherapy Institute, Fujian Medical University, Fuzhou, Fujian 350108, China; Department of Medicine (Medical Oncology), Yale University, New Haven, CT 06510, USA. Electronic address: lieping.chen@yale.edu.
Abstract

Lymphocyte-activation gene 3 (LAG-3) is an immune inhibitory receptor, with major histocompatibility complex class II (MHC-II) as a canonical ligand. However, it remains controversial whether MHC-II is solely responsible for the inhibitory function of LAG-3. Here, we demonstrate that fibrinogen-like protein 1 (FGL1), a liver-secreted protein, is a major LAG-3 functional ligand independent from MHC-II. FGL1 inhibits antigen-specific T cell activation, and ablation of FGL1 in mice promotes T cell immunity. Blockade of the FGL1-LAG-3 interaction by monoclonal Antibodies stimulates tumor immunity and is therapeutic against established mouse tumors in a receptor-ligand inter-dependent manner. FGL1 is highly produced by human Cancer cells, and elevated FGL1 in the plasma of Cancer patients is associated with a poor prognosis and resistance to anti-PD-1/B7-H1 therapy. Our findings reveal an immune evasion mechanism and have implications for the design of Cancer Immunotherapy.

Keywords

FGL1; LAG-3; cancer; immunology; immunotherapy; tumor immune-evasion mechanism.

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