Recombinant Mouse TNFRH3/TNFRSF26 Fc Chimera Protein, CF

Mouse TNFRH3 (Tumor necrosis factor receptor homolog 3; designated TNFR superfamily member 26) is a member of the TNF receptor superfamily. Northern blot analysis indicates its expression in the mouse spleen and thymus, and by a variety of mouse lymphoid cell lines (1). Mature mouse TNFRH3 is a 21 kDa (predicted, unglycosylated), 185 amino acid (aa) type I transmembrane protein that contains a 145 aa extracellular domain (ECD) and a 19 aa cytoplasmic domain. The ECD contains two potential sites of N‑linked glycosylation and three TNFR-Cys repeats that characterize TNF receptors, while the cytoplasmic portion lacks a death domain (1). No ortholog to mouse TNFRH3 has been reported in human or rat (1). Two TNFRH3‑related mouse TNF receptor homologs, DcTRAIL R1 (TNFRSF23/TNFRH1, 35% aa sequence identity within the ECD) and DcTRAIL R2 (TNFRSF22/TNFRH2, 40% aa sequence identity within the ECD) are classed as TRAIL decoy receptors. One report indicates that TNFRH3 binding of transfected TRAIL/TNFSF10 is below limits of detection in a cell-based assay, and it is thus thought not to serve as a TRAIL decoy receptor (1). Similarly, binding was not detected to any of 38 human and mouse TNF superfamily members in a cell‑based assay (2). However, TNFRH3 does bind recombinant trimeric mouse TRAIL in R&D Systems’ direct ELISA assay.