Negative Selection and Central Tolerance

What is the goal of negative selection?

To eliminate thymocytes with high-affinity TCRs for self-antigens.

What is central tolerance?

The process of removing self-reactive lymphocytes in primary lymphoid tissues.

What transcription factor facilitates central tolerance in the thymic medulla?

AIRE (autoimmune regulator).

What does AIRE allow medullary thymic epithelial cells (mTECs) to do?

Express tissue-specific antigens for negative selection.

What cells engulf mTECs and present tissue-specific antigens via MHC class II?

Medullary thymic dendritic cells.

What is the fate of CD4+ thymocytes that express a self-reactive TCR and FOXP3?

They become natural regulatory T cells (nTregs).

What is the role of nTregs?

To promote peripheral tolerance and prevent autoimmune responses.