title: Role of Regulatory T Cells (Treg) and the Treg Effector Molecule Fibrinogen-like Protein 2 in Alloimmunity and Autoimmunity.
abstract: CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) are critical to the maintenance of immune tolerance. Treg are known to utilize a number of molecular pathways to control immune responses and maintain immune homeostasis. Fibrinogen-like protein 2 (FGL2) has been identified by a number of investigators as an important immunosuppressive effector of Treg, which exerts its immunoregulatory activity by binding to inhibitory FcγRIIB receptors expressed on antigen-presenting cells including dendritic cells, endothelial cells, and B cells. More recently, it has been suggested that FGL2 accounts for the immunosuppressive activity of a highly suppressive subset of Treg that express T cell immunoreceptor with Ig and ITIM domains (TIGIT). Here we discuss the important role of Treg and FGL2 in preventing alloimmune and autoimmune disease. The FGL2-FcγRIIB pathway is also known to be utilized by viruses and tumor cells to evade immune surveillance. Moving forward, therapies based on modulation of the FGL2-FcγRIIB pathway hold promise for the treatment of a wide variety of conditions ranging from autoimmunity to cancer.
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Chruscinski
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Hassan
authors.initials: H
authors.lastname: Sadozai
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rojas-Luengas
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Agata
authors.initials: A
authors.lastname: Bartczak
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Khattar
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Nazia
authors.initials: N
authors.lastname: Selzner
authors.affiliation: Multi-Organ Transplant Program, University Health Network, University of Toronto, Toronto, Canada.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Levy