Lymphocyte Development and Tolerance

These flashcards cover key concepts and terminology related to lymphocyte development, maturation, and the mechanisms of tolerance.

Lymphocyte

A type of white blood cell crucial for the immune response, including T-cells and B-cells.

Central tolerance

The process of eliminating self-reactive T-cells and B-cells during their development in primary lymphoid organs to prevent autoimmunity.

Peripheral tolerance

Mechanisms that suppress autoreactive lymphocytes that have escaped central tolerance, occurring outside the thymus or bone marrow.

Positive selection

The process in the thymus that ensures T-cells recognize self-MHC molecules and survive.

Negative selection

The elimination of T-cells that strongly react to self-antigens in the thymus, preventing autoimmunity.

Thymic education

The process where T-cells undergo maturation, including positive and negative selection in the thymus.

B-cell Maturation

The process by which B-cells develop from progenitors in the bone marrow and undergo gene rearrangements to become fully functional immune cells.

T-cell receptor (TCR) rearrangement

The genetic rearrangement process that allows T-cells to produce a unique TCR capable of recognizing specific antigens.

Autoimmune Regulator (AIRE)

A protein that promotes the expression of tissue-specific proteins in thymic epithelial cells to aid in negative selection of T-cells.

Receptor editing

A process in B-cell development where autoreactive B-cells can modify their B-cell receptors to avoid elimination.

Double-negative (DN) T-cell

An immature T-cell that does not express CD4 or CD8 co-receptors during development.

Double-positive (DP) T-cell

A T-cell that expresses both CD4 and CD8 markers, indicating a mature stage before selection.

Naïve B-cells

Mature B-cells that express IgM and IgD but have not yet encountered their specific antigen.

Transitional B-cells

B-cells that have left the bone marrow and are maturing in secondary lymphoid organs before becoming fully functional.

Chemokines and cytokines

Signaling molecules that guide the migration and maturation of lymphocytes.

Thymus

An organ where T-cells mature, undergoing processes crucial for self-tolerance and immune competence.

Bone marrow

The primary site of B-cell development and maturation that involves complex gene rearrangements.

Immunocompetent cells

Lymphocytes that have matured and can respond to antigens.

Signaling triggers

Molecular signals that initiate the next steps in B-cell and T-cell development after successful rearrangement of their respective antigen receptors.