The YLI-90 monoclonal antibody specifically reacts with the B6 alloantigen of Ly-49I, an inhibitory receptor which is expressed on subsets of natural killer (NK) cells, NK-1.1+ (or DX5+) T lymphocytes (NK-T cells), and on a population of memory CD8+ T lymphocytes in C57BL/6 mice, but not AKR/J, BALB/c, DBA/1, or SJL mice. The Ly-49 family of NK-cell receptors are disulfide-linked type-II transmembrane protein homodimers with extracellular carbohydrate-recognition domains (CRD). Ly-49I is closely related to Ly-49C[B6] and Ly49C[BALB], and these three alloantigens are recognized by mAb 5E6 (Cat. No. 553277). A Ly-49I[BALB] allele has not been found. The Ly-49 family members are expressed independently, such that an individual NK or T cell may display more than one class of Ly-49 receptor homodimers. Binding of Ly-49I-expressing transfectants to cell lines bearing MHC class I antigens of the b,d, k and s haplotypes was not detected. In contrast, Ly-49I-expressing transfectants were found to weakly bind lymphoblasts of the b, d, k, q, s, and v haplotypes and to strongly bind H-2[r] lymphoblasts. Ly-49I-bearing NK cells may mediate allogeneic and hybrid resistance to transplantation of H-2[d] bone marrow.
The antibody was conjugated to BD Horizon™ BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.