The Development of T Lymphocytes

This set of flashcards covers key terminology and concepts related to the development of T lymphocytes in the immune system, as outlined in the lecture notes.

T-cell development

The process by which T cells mature in the thymus, involving rearrangement of T-cell receptor genes.

Thymocytes

Immature T cells that develop in the thymus and commit to the T-cell lineage.

Positive selection

The process where T cells that recognize self-MHC molecules are selected to mature further.

Negative selection

The elimination of T cells that strongly recognize self antigens in the thymus.

CD4 T cells

A type of T cell that helps activate other immune cells; they recognize MHC class II molecules.

CD8 T cells

A type of T cell that can directly kill infected cells; they recognize MHC class I molecules.

TCR (T-cell receptor) rearrangement

The process that allows T cells to express a unique receptor, crucial for recognizing antigens.

Notch1

A receptor that plays a critical role in T-cell development by maintaining thymocyte lineage commitment.

AIRE (Autoimmune Regulator)

A transcription factor that promotes the expression of tissue-specific antigens in the thymus to aid in negative selection.

Regulatory T cells (Tregs)

A subset of CD4 T cells that help maintain tolerance to self-antigens and prevent autoimmune responses.

Double-negative thymocytes

Thymocytes that do not express CD4 or CD8, important for early T-cell development.

Double-positive thymocytes

Thymocytes that express both CD4 and CD8, resulting from positive selection.

Apoptosis

Programmed cell death; occurs in thymocytes that do not successfully rearrange their TCR.

Secondary lymphoid tissues

Areas where T cells, upon maturation, encounter antigens and differentiate into effector cells.