Ummune T cells: Anxiety and Fear

Activation of Immune T Cells Leads to Behavioral Changes

NEUROSCIENCE NEWSOCTOBER 23, 2017Summary: A new Nature Immunology study reveals immune cells alter the body’s metabolism when activated, leading to changes in behavior.

Source: RIKEN.

Scientists from the RIKEN Center for Integrative Medical Sciences in Japan and collaborators have found that T cells — immune cells that help to protect the body from infections and cancer — change the body’s metabolism when they are activated, and that this activation actually leads to changes in behavior.

It is currently known that individual T cells change their metabolism to meet their energy needs after being activated, but the systemic metabolic effect of sustained activation of the immune system has remained unexplored. To understand the systemic effects, the group looked at T cell activation in mice designed to lack a surface receptor called PD-1, which is necessary for inhibiting the activity of T cells. T cells remain activated in mice without the receptor, similar to those in the immune systems of people with certain types of autoimmune disease. In these mice, they found that amino acids–molecules that are used to build proteins–were depleted in the blood, and that they were increased in the T cells themselves, implicating the T cells in the change./.../

In these mice, they found that amino acids–molecules that are used to build proteins–were depleted in the blood, and that they were increased in the T cells themselves, implicating the T cells in the change. Image is in the public domain.

The researchers found that their depletion in mice without PD-1 resulted in behavioral changes dominated by anxiety and exacerbated fear responses, which could be remedied by providing a diet rich in an essential amino acid.