Neuro-immune interactions

Excerpt

The immune system harbors immense potential energy, which must be harnessed even in the face of the most egregious assaults by pathogenic organisms. From the outside, it may seem that immunity operates on a binary ON/OFF switch. In the absence of infection, the immune system seems invisible. Challenge it with even a single danger signal, and the kinetic energy of immune cells appears to be released in full force. In reality, there are intrinsic checks and balances that control the magnitude of immune responsiveness, such as central tolerance, suppressive cytokines, Treg cells, and checkpoint inhibitors, to name a few. Collectively, these control mechanisms effectively stabilize the immune system so that self/non-self discrimination acts as the main switch to engage a response. While these intrinsic regulatory pathways control major immune processes such as antigen recognition, immune homeostasis is an important facet of immune regulation that is often under appreciated. …