Definitions

Involved with T- Cell Activation 

Clonal anergy- This occurs when the body fails to react to presented antigen. When this occurs, it typically means the immune system is not capable of successfully initiating a response a pathogen, which may be a self- antigen.

Positive Costimulatory receptors- These are molecules that enhance TCR signaling. They induce expression of pro- proliferative cytokine IL-2along with prosurvival bcl-2 family member. For example, CD28 is a positive costimulatory receptor.


Negative Costimulatory receptors- These are molecules that inhibbit TCR signaling. They maintain peripheral T- cell tolerance and reduce inflammation after an infection and during responses to chronic infection.