To compare and contrast: The positive and negative selections of T-lymphocyte and the meaning of central tolerance. Concept introduction: T cell is a type of lymphocyte that plays an important role in the cell-mediated immunity. Thymocytes are the progenitor cells of T cells that migrate and colonize in the thymus. Before the process of conversion of thymocytes to T-cells, thymocytes undergo two different selection processes, namely positive and negative selections that are collectively known as thymic selection.

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Chapter 22.5, Problem 27LO

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To compare and contrast: The positive and negative selections of T-lymphocyte and the meaning of central tolerance.

Concept introduction: T cell is a type of lymphocyte that plays an important role in the cell-mediated immunity. Thymocytes are the progenitor cells of T cells that migrate and colonize in the thymus. Before the process of conversion of thymocytes to T-cells, thymocytes undergo two different selection processes, namely positive and negative selections that are collectively known as thymic selection.

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