How the TCR act in clonol section?

T-cell receptor (TCR) signaling plays a crucial role in clonal selection during T cell development in the thymus. When thymocytes expressing TCRs encounter self-antigens presented by thymic epithelial cells, those with low to moderate affinity are positively selected for survival, while those with high affinity for self-antigens undergo negative selection and are eliminated. This process ensures that the surviving T cells can effectively recognize foreign antigens while minimizing autoimmunity. Ultimately, clonal selection leads to a diverse repertoire of T cells capable of responding to a wide array of pathogens.