Where do Treg cells come from?

Tregs control the immune response to self and foreign particles (antigens) and help prevent autoimmune disease. Tregs produced by a normal thymus are termed ‘natural’. Treg formed by differentiation of naïve T cells outside the thymus, i.e. the periphery, or in cell culture are called ‘adaptive’.

Why are Treg cells important?

Regulatory T cells (Tregs) are a specialized subpopulation of T cells that act to suppress immune response, thereby maintaining homeostasis and self-tolerance. It has been shown that Tregs are able to inhibit T cell proliferation and cytokine production and play a critical role in preventing autoimmunity.

What are natural Treg cells?

Natural Treg cells. Natural CD4+CD25+Foxp3+ regulatory (or suppressor) Treg cells are the most-studied subset of suppressor CD4+ T cells. They are engaged in the control of immune self-tolerance, allograft rejection and allergy, and are also important in inhibiting the effector functions during infection and in tumors.

What is Treg differentiation?

Treg cells consist of heterogeneous subsets that have distinct phenotypes and functions. Upon antigen stimulation, naïve-like thymus-derived Treg cells, which circulate in secondary lymphoid organs, can differentiate into effector Treg (eTreg) cells and migrate to and control immune homeostasis of peripheral tissues.

What do Treg cells secrete?

Types. Regulatory T cells are a subset of T cells that can secrete tolerogenic cytokines such as IL-10 and suppress the proinflammatory functions of effector T cells such as their cytotoxicity, cytokine production, and proliferation.

Who discovered Treg?

Sakaguchi and coworkers
DISCOVERY OF REGULATORY T CELLS (Tregs) IN MOUSE AND HUMAN. Since the discovery of Tregs by Sakaguchi and coworkers (1995) two decades ago, our understanding of the CD4+ T helper (Th) cell subtype, first characterized by the expression of the interleukin (IL)-2 receptor α-chain (CD25), has vastly expanded.

How do Treg cells regulate immune response?

Conventional Th cells control the adaptive immunity by activating, in an antigen-specific fashion, other effector cells such as CD8+ cytotoxic T cells, B cells and macrophages. Treg cells are defined as T cells in charge of suppressing potentially deleterious activities of Th cells.

What is the normal development of human Treg cells?

Human Treg cells also develop early in fetal life and are detected in thymii at 12 weeks and in LN at 14 weeks (Cupedo et al., 2005; Michaelsson et al., 2006).

Why do human Treg cells decline with age?

Compared with naïve T cells, human Treg cells exhibit higher turnover, as measured by Ki67 expression (Silva et al., 2016; Thome et al., 2016a), which could also contribute to their declining frequency with age. Treg cell frequency may also be affected by changes in dendritic cell (DC) populations.

Do thymic recipients need immunosuppression after Treg transplant?

Interestingly, thymic recipients are tolerant of self and the thymic transplant (they require no immunosuppression) and also generate Treg cells with diverse repertoires (Chinn et al., 2013; Markert et al., 2010).

What affects the frequency of Treg cell induction?

Treg cell frequency may also be affected by changes in dendritic cell (DC) populations. In a recent study, human fetal DC were shown to promote Treg cell induction more readily than adult DCs (McGovern et al., 2017).