|Detection of IL‑1 RII in Human PBMCs stimulated to induce Tregs by Flow Cytometry. Human peripheral blood mononuclear cells (PBMCs), stimulated to induce Regulatory T Cells (Tregs) and gated on CD4+, were treated with 10 ug/mL Anti-CD3, 5 ug/mL Anti-CD28, 10 ng/mL Recombinant Human TGF‑ beta 1 (Catalog # 240-B), and 20 ng/mL Recombinant Human IL‑2 (Catalog # 202-IL) for 48 hours and stained with Rat Anti-Human LRRC32/GARP PE‑conjugated Monoclonal Antibody and either (A) Mouse Anti-Human IL‑1 RII APC‑conjugated Monoclonal Antibody (Catalog # FAB663A) or (B) Mouse IgG1 Allophycocyanin Isotype Control (Catalog # IC002A). View our protocol for Staining Membrane-associated Proteins.|
Two distinct types of receptors that bind the pleiotropic cytokines IL-1 alpha and IL-1 beta have been described. The IL-1 receptor type I is an 80 kDa transmembrane protein that is expressed predominantly by T cells, fibroblasts, and endothelial cells. IL-1 receptor type II is a 68 kDa transmembrane protein found on B lymphocytes, neutrophils, monocytes, large granular leukocytes, and endothelial cells. Both receptors are members of the immunoglobulin superfamily and show approximately 28% sequence similarity in their extracellular domains. The two receptor types do not heterodimerize in a receptor complex. An IL-1 receptor accessory protein that can heterodimerize with the type I receptor in the presence of IL-1 alpha or IL-1 beta, but not IL-1ra, was identified (1). This type I receptor complex appears to mediate all the known IL-1 biological responses. The receptor type II has a short cytoplasmic domain and does not transduce IL-1 signals. In addition to the membrane-bound form of IL-1 RII, a naturally-occurring soluble form of IL-1 RII has been described. It has been suggested that the type II receptor, either as the membrane-bound or as the soluble form, serves as a decoy for IL-1 and inhibits IL-1 action by blocking the binding of IL-1 to the signaling type I receptor complex. Recombinant IL-1 soluble receptor type II is a potent antagonist of IL-1 action.