1. Academic Validation
  2. Low-frequency CD8+ T cells induced by SIGN-R1+ macrophage-targeted vaccine confer SARS-CoV-2 clearance in mice

Low-frequency CD8+ T cells induced by SIGN-R1+ macrophage-targeted vaccine confer SARS-CoV-2 clearance in mice

  • NPJ Vaccines. 2024 Sep 18;9(1):173. doi: 10.1038/s41541-024-00961-6.
Daisuke Muraoka # 1 2 Meng Ling Moi # 3 4 Osamu Muto 5 6 Takaaki Nakatsukasa 7 8 Situo Deng 7 Chieko Takashima 9 Rui Yamaguchi 5 6 Shin-Ichi Sawada 10 Haruka Hayakawa 11 Thi Thanh Ngan Nguyen 12 Yasunari Haseda 13 Takatoshi Soga 13 Hirokazu Matsushita 9 Hiroaki Ikeda 7 Kazunari Akiyoshi 14 Naozumi Harada 13
Affiliations

Affiliations

  • 1 Department of Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. d.muraoka@aichi-cc.jp.
  • 2 Division of Translational Oncoimmunology, Aichi Cancer Center Research Institute, Nagoya, Japan. d.muraoka@aichi-cc.jp.
  • 3 School of International Health, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan. sherry@m.u-tokyo.ac.jp.
  • 4 Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. sherry@m.u-tokyo.ac.jp.
  • 5 Division of Cancer Systems Biology, Aichi Cancer Center Research Institute, Nagoya, Japan.
  • 6 Division of Cancer Informatics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
  • 7 Department of Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
  • 8 Department of Surgical Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
  • 9 Division of Translational Oncoimmunology, Aichi Cancer Center Research Institute, Nagoya, Japan.
  • 10 Synergy Institute for Futuristic Mucosal Vaccine Research and Development (cSIMVa), Chiba University, Chiba, Japan.
  • 11 School of International Health, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan.
  • 12 Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
  • 13 United Immunity, Co., Ltd., Tokyo, 103-0022, Japan.
  • 14 Department of Immunology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  • # Contributed equally.
Abstract

Vaccine-induced T cells and neutralizing antibodies are essential for protection against SARS-CoV-2. Previously, we demonstrated that an antigen delivery system, pullulan nanogel (PNG), delivers vaccine antigen to lymph node medullary macrophages and thereby enhances the induction of specific CD8+ T cells. In this study, we revealed that medullary macrophage-selective delivery by PNG depends on its binding to a C-type lectin SIGN-R1. In a K18-hACE2 mouse model of SARS-CoV-2 Infection, vaccination with a PNG-encapsulated receptor-binding domain of spike protein decreased the viral load and prolonged the survival in the CD8+ T cell- and B cell-dependent manners. T cell receptor repertoire analysis revealed that although the vaccine induced T cells at various frequencies, low-frequency specific T cells mainly promoted virus clearance. Thus, the induction of specific CD8+ T cells that respond quickly to viral Infection, even at low frequencies, is important for vaccine efficacy and can be achieved by SIGN-R1+ medullary macrophage-targeted antigen delivery.

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