What is peripheral tolerance of T cells?

Peripheral tolerance is the second branch of immunological tolerance, after central tolerance. It takes place in the immune periphery (after T and B cells egress from primary lymphoid organs). Its main purpose is to ensure that self-reactive T and B cells which escaped central tolerance do not cause autoimmune disease.

Which type of lymphocyte goes through peripheral tolerance?

Peripheral tolerance is the immunological unresponsiveness of mature lymphocytes to self-antigens in the peripheral tissues. Mature CD4 T cells become unresponsive when they receive antigen stimulation in the absence of costimulatory signals or when the inhibitory receptors are engaged, for example, CTLA-4 and PD-1.

What is peripheral tolerance in immunology?

Definition. Peripheral tolerance describes the mechanisms that take place outside of primary lymphoid tissues to prevent lymphocytes from initiating potentially dangerous immune responses against the body’s own tissues, or against other harmless materials, such as food or commensal organisms.

How does tolerance to self antigen develop among T lymphocytes?

T-Cell central tolerance is controlled in the thymus during T-Cell maturation. The cortical epithelial cells of the thymus present self-antigen to CD4+ and CD8+ T-Cells. Maturing T-Cells which bind strongly to self-antigens are clonally deleted through apoptosis.

What are the mechanisms of peripheral tolerance in lymphocytes?

Mechanisms of peripheral tolerance include direct inactivation of effector T cells by either clonal deletion, conversion to regulatory T cells (Tregs) or induction of anergy. Tregs, which are also generated during thymic T cell development, further suppress the effector functions of conventional lymphocytes in the periphery.

How does peripheral tolerance work in thymic T cells?

Peripheral tolerance. Mechanisms of peripheral tolerance include direct inactivation of effector T cells by either clonal deletion, conversion to regulatory T cells (Tregs) or induction of anergy. Tregs, which are also generated during thymic T cell development, further suppress the effector functions of conventional lymphocytes in the periphery.

How is peripheral tolerance related to central tolerance?

Dependence of a particular antigen on either central or peripheral tolerance is determined by its abundance in the organism. B cell peripheral tolerance is much less studied and is largely mediated by B cell dependence on T cell help.

Why is it important to have a T lymphocyte?

T lymphocyte tolerance is particularly important, because it impacts B-cell tolerance as well, through the requirement of T cell help in antibody responses. Thus, failure of T-cell tolerance can lead to many different autoimmune diseases.