Treg cells are immunoregulatory Th cells that control autoimmunity in the peripheral blood through dominant tolerance. Types of Treg cells include the following:

 • Natural CD4+ Treg cells

• Th3 cells

• Tr1 cells

• CD8+ Treg cells

Natural Treg cells, characterized by constitutive expression of CD25, are developed primarily in the thymus from positively selected thymocytes with a relatively high avidity for self-antigens. Natural Treg cells represent approximately 5% to 10% of the total CD4+ T cell population. The signal to develop into Treg cells is thought to come from interactions between the TCR and MHC class II self-peptide complex expressed on the thymic stroma. In humans, natural Treg cells express CD4 and CD25.

Other types of Treg cells that can develop in the periphery are Tr1 and Th3 cells. Tr1 cells are CD4+ and are functionally induced by IL-10. These Treg cells, in turn, secrete IL-10 and regulate the immune system. Th3 progenitor cells are also CD4+. In vitro CD4+ cells have been shown to secrete trans forming growth factor β (TGF-β). CD8+ Treg cells are less well characterized and are reportedly capable of suppressing CD4+ cells in vitro.

مواضيع ذات صلة

Helper T Lymphocytes

Sites of Lymphocyte Development

MONOCYTE-MACROPHAGE DISORDERS

Clinical Features of HIV Infection and AIDS

Pathogenesis of AIDS

Congenital Immunodeficiencies : Defects in Lymphocyte Activation and Function

Congenital Immunodeficiencies: Defects in Lymphocyte Maturation

Congenital Immunodeficiencies: Defects in Innate Immunity

Congenital (Primary) Immunodeficiencies

Neuroimmunology: Interactions Between the Immune and Nervous Systems

Disorders of Neutrophils

Cell Surface Receptors