TNFRSF18

TNFRSF18
Identifiers
Aliases	TNFRSF18, AITR, CD357, GITR, GITR-D, tumor necrosis factor receptor superfamily member 18, TNF receptor superfamily member 18, ENERGEN
External IDs	OMIM: 603905 MGI: 894675 HomoloGene: 48270 GeneCards: TNFRSF18
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1p36.33 Start 1,203,508 bp[1] End 1,206,592 bp[1]
Gene location (Mouse) Chr. Chromosome 4 (mouse)[2] Band 4|4 E2 Start 156,110,621 bp[2] End 156,113,352 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in skin of abdomen tibialis anterior muscle spleen blood appendix bone marrow cells minor salivary gland canal of the cervix lymph node deltoid muscle Top expressed in thymus blood lip spleen zone of skin skin of abdomen ascending aorta aortic valve skin of back bone marrow More reference expression data BioGPS n/a
Gene ontology Molecular function tumor necrosis factor-activated receptor activity protein binding Cellular component integral component of membrane extracellular region plasma membrane integral component of plasma membrane membrane Biological process apoptotic process multicellular organism development response to lipopolysaccharide inflammatory response tumor necrosis factor-mediated signaling pathway regulation of cell population proliferation immune response signal transduction positive regulation of leukocyte migration negative regulation of apoptotic process regulation of apoptotic process apoptotic signaling pathway positive regulation of tyrosine phosphorylation of STAT protein regulation of regulatory T cell differentiation positive regulation of cell adhesion Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 8784 21936 Ensembl ENSG00000186891 ENSMUSG00000041954 UniProt Q9Y5U5 O35714 RefSeq (mRNA) NM_148902 NM_004195 NM_148901 NM_009400 NM_021985 RefSeq (protein) NP_004186 NP_683699 NP_683700 NP_033426 NP_068820 Location (UCSC) Chr 1: 1.2 – 1.21 Mb Chr 4: 156.11 – 156.11 Mb PubMed search [3] [4]
Wikidata
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Tumor necrosis factor receptor superfamily member 18 (TNFRSF18), also known as glucocorticoid-induced TNFR-related protein (GITR) or CD357. GITR is encoded and tnfrsf18 gene at chromosome 4 in mice. GITR is type I transmembrane protein and is described in 4 different isoforms. ^[5][6] GITR human orthologue, also called activation-inducible TNFR family receptor (AITR), is encoded by the TNFRSF18 gene at chromosome 1. ^[7][8]

Function

GITR is a member of TNFR superfamily and shares high homology in cytoplasmic domain, characterized with cysteine pseudo-repeats, with other members of TNFRSF, such as CD137, OX40 or CD27. ^[8] GITR is constitutively expressed on CD25+CD4+ regulatory T cells and its expression is upregulated on all T cell subsets after activation. GITR is also expressed on murine neutrophils and NK cells. ^[9]

GITR interacts with its ligand (GITRL) that is expressed on antigen-presenting cells (APC) and endothelial cells. ^[9]

AITR

Human activation-inducible tumor necrosis factor receptor (AITR) and its ligand, AITRL, are important costimulatory molecules in the pathogenesis of autoimmune diseases. Despite the importance of these costimulatory molecules in autoimmune disease, their role in the autoimmune reaction to herniated disc fragments has yet to be explored.^[10]

GITR

GITR was identified as a new member of the TNF receptor superfamily, by comparing gene expression in untreated and DEX-treated murine T-cell lines. ^[5]

GITR is co-stimulatory surface receptor for T cells and after interaction with GITRL maintain T cell activation, proliferation, cytokine production, and rescue T cells from anti-CD3-induced apoptosis. GITR can be used as Treg marker and its signaling abrogates the suppressive function of regulatory T cells. Also, GITR plays role in Treg development, as it is expressed already at CD4+CD25+Foxp3- Treg progenitors. ^{[9][11][12][13][14]}

GITR^-/- mice has no developmental problem and are fertile. They have complete block in anti-CD3-induced T cell activation and decrease in regulatory T cells progenitors. After infection challenge, GTIR^-/- mice developed less inflammation than WT littermates. ^{[13][15][11][14]}

GITR signaling

GITR does not have any enzymatic activity and signaling is propagated via recruiting TRAF-family members, specifically TRAF1, TRAF2 and TRAF5, to the GITR-signaling complex. The signaling is then mediated through NF-kB and MAPK pathways. There is an evidence that GITR has unique role for CD8+ and CD4+ T cells. GITR signaling lowers the threshold for CD28 signaling on CD8+ T cells or induces expression of CD137 on CD8+ memory T cells. For CD4+ regulatory T cells, GITR signaling promotes their expansion, inhibits Treg suppressive capacity and promotes resistance of effector T cells to Treg suppression. ^[11][16]

GITR in disease

GITR is in high interest as one of the immune checkpoint molecules that have potential in cancer treatment. GITR signaling can promote antitumor and anti-infective immune response, but also can be a driver of autoimmune diseases. Different response to GITR signaling rely on the GITR expression on different immune cell types. How GITR signaling is modulated in the different cells remains unknown. GITR agonistic antibodies are in the clinical trials as activators of effector CD8 T cells, while decreasing number of circulating suppressive regulatory T cells. Limited response to GITR agonistic antibodies is enhanced in combination with anti-PD-1 or anti-CTLA-4 therapies. ^{[9][12][11][16]}

GITR^-/- mice in pancreatitis model have reduced IkBα and decreased expression of NF-kB p65 protein in pancreatic tissue, and also increased pro-apoptotic markers (e.g. Bax) and decreased anti-apoptotic markers (e.g. Bcl-2). ^[11][17]

Asthma model: GITR activation drives an infiltration of eosinophils to the lungs and induces production of cytokines. Model of arthritis: GITR activation increase numbers of Th17 cells in secondary lymphoid organs and stimulate cytokine production. Model of atopic dermatitis: GITR-GITRL pathway activation supports the production of attractants of regulatory T cells (CCL17 and CCL27) and promotes production of Th2-induced cytokines. Inhibition of GITR-GITRL pathway potentially may decrease a severity of different diseases, as asthma, arthritis or atopic dermatitis. ^{[11][18][19][20]}

Atherosclerosis

Atherosclerosis is autoinflammatory disease that belongs to the group of cardiovascular diseases (CVD). In atherosclerosis progression, plaques with modified low density lipoprotein (LDL) are formed. GITR expression was detected in plaques macrophages and T cells. Moreover, soluble GITR (sGITR) was present in patient's plasma. GITR potentially might be used as a biomarker of CVD patients, as its plaque expression and levels in plasma can distinguish the CVD patients from healthy controls. ^[21][11]

References

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

This page was last edited on 8 February 2024, at 04:11