BCG-induced trained immunity: history, mechanisms and potential applications

Jingjing Chen; Li Gao; Xinya Wu; Yuxin Fan; Meixiao Liu; Li Peng; Jieqin Song; Bingxue Li; Aihua Liu; Fukai Bao

doi:10.1186/s12967-023-03944-8

BCG-induced trained immunity: history, mechanisms and potential applications

J Transl Med. 2023 Feb 10;21(1):106. doi: 10.1186/s12967-023-03944-8.

Authors

Jingjing Chen^#^{1

2}, Li Gao^#^{1

2}, Xinya Wu^#^{1

3}, Yuxin Fan^{1

3}, Meixiao Liu^{1

3}, Li Peng^{1

2}, Jieqin Song^{1

3}, Bingxue Li^{1

3}, Aihua Liu^{4

5

6}, Fukai Bao^{7

8

9}

Affiliations

¹ The Institute for Tropical Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China.
² Department of Biochemistry and Molecular Biology, Kunming Medical University, Kunming, 650500, Yunnan, China.
³ Department of Microbiology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, China.
⁴ The Institute for Tropical Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China. liuaihua@kmmu.edu.cn.
⁵ Yunnan Health Cell Biotechnology Company, Kunming, 650041, Yunnan, China. liuaihua@kmmu.edu.cn.
⁶ Department of Biochemistry and Molecular Biology, Kunming Medical University, Kunming, 650500, Yunnan, China. liuaihua@kmmu.edu.cn.
⁷ The Institute for Tropical Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China. baofukai@kmmu.edu.cn.
⁸ Yunnan Health Cell Biotechnology Company, Kunming, 650041, Yunnan, China. baofukai@kmmu.edu.cn.
⁹ Department of Microbiology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, China. baofukai@kmmu.edu.cn.

^# Contributed equally.

Abstract

The Bacillus Calmette-Guérin (BCG) vaccine was discovered a century ago and has since been clinically applicable. BCG can not only be used for the prevention of tuberculosis, but also has a non-specific protective effect on the human body called trained immunity that is mediated by innate immune cells such as monocytes, macrophages, and natural killer cells. Mechanisms of trained immunity include epigenetic reprogramming, metabolic reprogramming, and long-term protection mediated by hematopoietic stem cells. Trained immunity has so far shown beneficial effects on cancer, viral-infections, autoimmune diseases, and a variety of other diseases, especially bladder cancer, respiratory viruses, and type 1 diabetes. The modulation of the immune response by BCG has led to the development of a variety of recombinant vaccines. Although the specific mechanism of BCG prevention on diseases has not been fully clarified, the potential role of BCG deserves further exploration, which is of great significance for prevention and treatment of diseases.

Keywords: BCG; Cancer; Epigenetic reprogramming; Metabolic reprogramming; Trained immunity; Viral infection.

Publication types

Review
Research Support, Non-U.S. Gov't

MeSH terms

BCG Vaccine / therapeutic use
Humans
Immunity, Innate
Macrophages
Mycobacterium bovis*
Trained Immunity
Tuberculosis* / prevention & control

Substances

BCG Vaccine