Genetic predisposition and environmental factors & Failure to ensure tolerance

How can genetics contribute to autoimmunity?

Genetic predisposition can result from MHC polymorphisms that present self-antigens to autoreactive T cells.

What environmental factors can increase the risk of autoimmunity?

Chemical exposure and physical trauma can increase the risk of developing autoimmune diseases.

What can cause failure of tolerance in T cells?

Failure of negative selection can allow autoreactive T cells to survive.

How can T-cell activation lead to autoimmunity?

Failure to regulate T-cell activation can result in immune responses against self.

What happens when costimulatory signals are lost?

Loss of the requirement for a costimulatory signal can reduce peripheral tolerance.

What is the role of regulatory T cells in tolerance?

Failure of regulatory T cells to act can lead to loss of tolerance and autoimmunity.