CD4+ regulatory T (Treg) cells have a profound ability to suppress host immune responses, yet little is understood about how these cells are regulated. We describe a mechanism linking Toll-like receptor (TLR) 8 signaling to the control of Treg cell function, in which synthetic and natural ligands for human TLR8 can reverse Treg cell function. This effect was independent of dendritic cells but r...

PROBLEM During pregnancy, the maternal immune system needs to adapt in order not to reject the semi-allogenic fetus. METHOD In this review, we describe and discuss the role of regulatory T (Treg) cells in fetal tolerance. RESULTS Treg cells constitute a T helper lineage that is derived from thymus (natural Treg cells) or is induced in the periphery (induced Treg cells). Treg cells are enric...

Regulatory T cells (Treg) are important in maintaining tolerance to self tissues. As both CD28 and CTLA-4 molecules are implicated in the function of Treg, we investigated the ability of their two natural ligands, CD80 and CD86, to influence the Treg-suppressive capacity. During T cell responses to alloantigens expressed on dendritic cells, we observed that Abs against CD86 potently enhanced su...

Adoptive transfer of freshly isolated natural occurring CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) prevents graft-versus-host disease (GVHD) in several animal models and following hematopoietic cell transplantation (HCT) in clinical trials. Donor-derived Treg have been mainly used, as they share the same MHC with CD4(+) and CD8(+) conventional T cells (Tcon) that are primarily responsible ...

T regulatory (Treg) cells expressing the transcription factor FoxP3 play a key role in protection against autoimmune disease. GFP-FoxP3 reporter mice have been used widely to study the induction, function and stability of both thymically- and peripherally-induced Treg cells. The N-terminal modification of FoxP3, however, affects its interaction with transcriptional co-factors; this can alter Tr...

Graft versus host disease (GVHD) is the major complication of allogeneic hematopoietic stem cell transplantation. GVHD is characterized by an imbalance between the effector and regulatory arms of the immune system which results in the over production of inflammatory cytokines. Moreover, there is a persistent reduction in the number of regulatory T (Treg) cells which limits the ability of the im...

Maintaining immune tolerance requires the production of Foxp3-expressing regulatory T (Treg) cells in the thymus. Activation of NF-κB transcription factors is critically required for Treg cell development, partly via initiating Foxp3 expression. NF-κB activation is controlled by a negative feedback regulation through the ubiquitin editing enzyme A20, which reduces proinflammatory signaling in m...

Autologous stem cell transplantation (ASCT) is a last resort treatment for refractory juvenile idiopathic arthritis (JIA). It has been shown to induce dramatic and long-term improvements, but the underlying mechanisms remain to be elucidated. We investigated the potential role of regulatory T cells (Treg) in the processes of immune reconstitution and re-establishment of immune tolerance followi...