Tregs

The bidirectional interaction between the immune system and whole-body metabolism has been well recognized for many years. Via effects on adipocytes and hepatocytes, immune cells can modulate whole-body metabolism (in metabolic syndromes such as type 2 diabetes and obesity) and, reciprocally, host nutrition and commensal-microbiota-derived metabolites modulate immunological homeostasis. Studies demonstrating the metabolic similarities of proliferating immune cells and cancer cells have helped give birth to the new field of immunometabolism, which focuses on how the cell-intrinsic metabolic properties of lymphocytes and macrophages can themselves dictate the fate and function of the cells and eventually shape an immune response...

No abstract text is available yet for this article.

Memory for antigen is a defining feature of adaptive immunity. Antigen-specific lymphocyte populations show an increase in number and function after antigen encounter and more rapidly re-expand upon subsequent antigen exposure. Studies of immune memory have primarily focused on effector B cells and T cells with microbial specificity, using prime-challenge models of infection. However, recent work has also identified persistently expanded populations of antigen-specific regulatory T cells that protect against aberrant immune responses...

Dietary antigens are normally rendered nonimmunogenic through a poorly understood "oral tolerance" mechanism that involves immunosuppressive regulatory T (Treg) cells, especially Treg cells induced from conventional T cells in the periphery (pTreg cells). Although orally introducing nominal protein antigens is known to induce such pTreg cells, whether a typical diet induces a population of pTreg cells under normal conditions thus far has been unknown. By using germ-free mice raised and bred on an elemental diet devoid of dietary antigens, we demonstrated that under normal conditions, the vast majority of the small intestinal pTreg cells are induced by dietary antigens from solid foods...

Regulatory T (Treg) cells, as central mediators of immune suppression, play crucial roles in many aspects of immune system's physiology and pathophysiology. The transcription factor Foxp3 has been characterized as a master gene of Tregs. Yet Treg cells possess a distinct pattern of gene expression, including upregulation of immune-suppressive genes and silencing of inflammatory cytokine genes. Recent studies have revealed the molecular mechanisms that establish and maintain such gene regulation in Treg cells...

The cytokine TGF-β plays an integral role in regulating immune responses. TGF-β has pleiotropic effects on adaptive immunity, especially in the regulation of effector and regulatory CD4(+) T cell responses. Many immune and nonimmune cells can produce TGF-β, but it is always produced as an inactive complex that must be activated to exert functional effects. Thus, activation of latent TGF-β provides a crucial layer of regulation that controls TGF-β function. In this review, we highlight some of the important functional roles for TGF-β in immunity, focusing on its context-specific roles in either dampening or promoting T cell responses...