Negative selection in the thymus ensures central tolerance by eliminating T cells with which property?

• A. High-affinity recognition of foreign antigens
• B. Low-affinity recognition of self-antigens
• C. High-affinity recognition of self-antigens
• D. Any recognition of self-antigens

Answer: (C)

Central tolerance in T cells is shaped in the thymus through selective processes. During negative selection, thymocytes that bind self-peptide–MHC complexes with high affinity are deleted, because such strong self-reactivity could lead to autoimmunity. This means the T cells eliminated are those with high-affinity recognition of self-antigens. In contrast, thymocytes that recognize self-antigens only weakly can pass through (they may be retained if they’re useful in the repertoire), and recognition of foreign antigens isn’t targeted for deletion by this mechanism. So the property being eliminated is high-affinity recognition of self-antigens.