What does "Trained Immunity" mean?
Table of Contents
Trained immunity refers to the ability of certain immune cells to remember past infections or exposures to specific substances. This memory allows them to respond more effectively when faced with the same or similar challenges in the future.
How It Works
When immune cells, such as macrophages, encounter a substance like beta-glucan or a pathogen, they become "trained." This means they change in a way that helps them act faster and stronger during later encounters. This process involves various changes within the cell, including adjustments in their genes and metabolism.
Importance of Metabolism
A key part of trained immunity involves a molecule called S-adenosylmethionine (SAM). SAM helps control many functions within the cell. If SAM levels drop, the trained immune cells may not work as well, leading to a weaker response to infections.
Role of Cellular Signals
Certain signals in the body, like those from the STAT1 pathway, help guide the training of immune cells. These signals can change over time, which affects how well the immune cells respond later on. After initial exposure, the immune cells continue to evolve, developing into a stronger defense mechanism.
Local Protection
Trained immunity not only enhances the immune response but can also provide local protection within specific tissues, such as the spleen. When immune cells are trained, they can better manage future threats in that area, leading to long-lasting protection.