The TM-β1 monoclonal antibody specifically recognizes the 90-100-kDa β chain shared by the IL-2 and IL-15 receptors (IL-2Rβ, CD122). In the periphery, CD122 is expressed on CD8+ T lymphocytes, NK cells, NK-T cells, dendritic epidermal T cells, subsets of intraepithelial lymphocytes, and macrophages. Small subsets of fetal and adult thymocytes constitutively express CD122. CD122+ cells in the bone marrow include committed NK-cell progenitors. IL-2Rβ expression is upregulated by IL-2. CD122 is a transmembrane glycoprotein of the hematopoietin receptor superfamily which can combine with CD132 (γc) alone or CD132 plus CD25 (IL-2Rα) to form intermediate or high-affinity IL-2 receptor complexes, respectively. The β chain of these complexes, CD122, is involved in signal transduction and immunoregulation. The TM-β1 antibody blocks high affinity binding of IL-2 or IL-15 to IL-2Rβ.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.