Other Proteins

GITR, also known as tumor necrosis factor receptor superfamily 18 (TNFRSF18), is a member of the receptor family bearing the same name that is expressed on the surfaces of cells involved in both adaptive and innate immunity, including CD4+ T cells, CD8+ T cells, natural killer cells, B cells, macrophages, and dendritic cells. Like all other TNFRSF members, GITR regulates the duration, phenotype, and degree by which the immune system responds to antigens. The National Cancer Institute regards GITR as the 12th most important molecule involved in immunotherapy, as it plays a major role in modulating both inflammatory and immune responses. The receptor has attracted the attention of immunologists for its potential as a costimulatory immune checkpoint molecule in immunotherapy. Expressed in peripheral tissues as well as endothelial cells, GITR inhibits T cell receptor-induced apoptosis via its cross-linking mechanism, thereby creating an environment that promotes T cell longevity and survival. To accomplish this task, GITR initiates signal transduction by activating nuclear factor κB (NF-κB) along with the following specific mitogen-activated protein kinase (MAPK) pathways: extracellular signal-related kinases (ERKs), c-Jun N-terminal kinase (JNK), and p38. Several bone disorders, such as familial expansive osteolysis, autosomal recessive osteopetrosis and Paget’s disease, have been attributed to GITR mutations due to its key role in regulating osteoclast and lymph node development. PeproTech’s CHO cell-derived Recombinant Human GITR/TNFRSF18 Fc is a glycosylated, disulfide-linked homodimer of 738 amino-acid-residues whose monomer consists of a 136-amino-acid extracellular domain fused to the 231-amino-acid length Fc portion of human IgG by two glycine residues. The calculated molecular weight of monomeric CHO cell-derived Recombinant Human GITR/TNFRSF18 Fc is 40.6 kDa; however, due to glycosylation, it migrates at an apparent molecular weight of approximately 45-50 kDa by SDS-PAGE analysis under reducing conditions.