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

The Bacillus Calmette-Guerin (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.

Automated summary

The BCG vaccine, discovered a century ago, is not only effective in preventing tuberculosis but also has a non-specific protective effect known as trained immunity, mediated by innate immune cells. Trained immunity, involving epigenetic and metabolic reprogramming, as well as long-term protection by hematopoietic stem cells, has shown beneficial effects on cancer, viral infections, autoimmune diseases, and other diseases. The immune response modulation by BCG has led to the development of recombinant vaccines, and further exploration of its potential role is of great significance for disease prevention and treatment.