New insights reveal how T cells know not to go after our beneficial microbiota
The immune system continuously protects the body from attack by foreign intruders. T lymphocytes play a crucial role in defending against any pathogen's assault. T cell development takes place in the thymus where these cells undergo "thymic education" and learn how to differentiate between self and foreign invaders. And yet the human gastrointestinal (GI) tract is inhabited with trillions of beneficial commensal bacteria. They help to regulate host nutrient metabolism and immune cell homeostasis, and they also protect from pathogen infection. Surprisingly, T cells learn to ignore beneficial microbiota in the intestine while they immediately try to recognize and eliminate any foreign invader in our body.