The 4E5 antibody reacts with Ly-49D, which is expressed on subsets of natural killer (NK) cells in C57BL/6, C3H/He (at a very low frequency), and SJL, but not DBA/2, AKR, CBA/J, or BALB/c mice. Unlike Ly-49D antigen has not been betected on NK-1.1+ (or DX5+) T cells. In 129/J mice, the 4E5 antibody cross-reacts with Ly-49O, Ly-49R, and Ly-49V. The Ly-49 family of NK-cell receptors, members of the C-type lectin superfamily, are disulfide-linked type-II transmembrane protein homodimers with extracellular carbohydrate-recognition domains, which bind to MHC class I alloantigens. 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. Ly-49D weakly binds to MHC class I antigens of the k halpotype, and Ly-49D+ IL-2-activated NK cells lyse target cells expressing H-2[a], H-2[b], H-2[d], H-2[k], H-2[p], H-2[q], and H-2[s] and the CHO (Chinese hamster ovary) cell line. Ly-49D+ cells mediate allogenic resistance to H-2d bone marrow transplantation. In vitro studies suggest that the Ly-49D receptor mediates activation of NK-cell cytolytic activity via tyrosine phosphorylation of their ITIMs (Immunoreceptor Tyrosine-based Inhibitory Motifs). Molecular differences between the Ly-49D stimulatory receptor and the inhibitory members of the Ly-49 family include the absence of an ITIM in Ly-49D, the lack of phosphorylation of Ly-49D in activated NK cells, and the association of a novel tyrosine-phosphorylated protein (pp16) with Ly-49D in activated NK cells. Ly-49O and Ly-49V are closely related to Ly-49A[B6] and, like Ly-49A, have ITIM domains. Ly-49O- and Ly-49V-transfected 293T (human kidney epithelial) cells bind tetramers of H-2D[b], D[b], D[k], and L[d]. In addition, the Ly-49V-transfected cells also bind K[b], K[d], and K[k]. Ly-49R is closely related to Ly-49D[B6] and is putative activating receptor due to its lack of an ITIM domain. Ly-49R-transfected 293T cells bind soluble tetramers of H-2D[b], D[d], D[k], and L[d]. Two-color analysis of Ly-49D expression on splenic NK cells. C57Bl/6 splenocytes were simultaneously stained with PE-conjugated mAb PK136 (anti-mouse NK-1.1, Cat. No. 557391/553165, both panels) and purified 4E5 mAb (right panel), followed by FITC-conjugated goat anti-rat Ig (Cat. No. 554016, both panels). Flow cytometry was performed on a FACScan™ .
BD Pharmingen™ Purified Rat Anti-Mouse Ly-49D - Purified - Clone 4E5 - Isotype Rat IgG2a, κ - Reactivity Ms - 0.5 mg
Purification
The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography.