About InVivoMAb anti-mouse Delta-like protein 1 (DLL1) The HMD1-5 monoclonal antibody reacts with mouse Delta-like protein 1 (DLL1) one of many Notch ligands. DLL1 is expressed by thymic and splenic stromal cells, macrophages, and dendritic cells. The Notch pathway is an important intercellular signaling pathway that plays a major role in controlling cell fate. The HMD1-5 antibody has been shown to neutralize DLL1 in vivo. InVivoMAb anti-mouse Delta-like protein 1 (DLL1) Specifications IsotypeArmenian Hamster IgG, κ Recommended Isotype Control(s)InVivoMAb polyclonal Armenian hamster IgG Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenMouse DLL1 Reported Applicationsin vivo DLL1 neutralization Flow cytometry FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtered ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein G RRIDAB_10950546 Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze. Application ReferencesInVivoMAb anti-mouse Delta-like protein 1 (DLL1) (CLONE: HMD1-5)Sakai, M., et al (2019). "Liver-Derived Signals Sequentially Reprogram Myeloid Enhancers to Initiate and Maintain Kupffer Cell Identity" Immunity 51(4): 655-670.e658. PubMedTissue environment plays a powerful role in establishing and maintaining the distinct phenotypes of resident macrophages, but the underlying molecular mechanisms remain poorly understood. Here, we characterized transcriptomic and epigenetic changes in repopulating liver macrophages following acute Kupffer cell depletion as a means to infer signaling pathways and transcription factors that promote Kupffer cell differentiation. We obtained evidence that combinatorial interactions of the Notch ligand DLL4 and transforming growth factor-b (TGF-β) family ligands produced by sinusoidal endothelial cells and endogenous LXR ligands were required for the induction and maintenance of Kupffer cell identity. DLL4 regulation of the Notch transcriptional effector RBPJ activated poised enhancers to rapidly induce LXRα and other Kupffer cell lineage-determining factors. These factors in turn reprogrammed the repopulating liver macrophage enhancer landscape to converge on that of the original resident Kupffer cells. Collectively, these findings provide a framework for understanding how macrophage progenitor cells acquire tissue-specific phenotypes.Riella, L. V., et al (2011). "Blockade of Notch ligand delta1 promotes allograft survival by inhibiting alloreactive Th1 cells and cytotoxic T cell generation" J Immunol 187(9): 4629-4638. PubMedThe Notch signaling pathway has been recently shown to contribute to T cell differentiation in vitro. However, the in vivo function of Notch signaling in transplantation remains unknown. In this study, we investigated the importance of Delta1 in regulating the alloimmune response in vivo. Delta1 expression was upregulated on dendritic cells and monocytes/macrophages upon transplantation in a BALB/c into B6 vascularized cardiac transplant model. Whereas administration of anti-Delta1 mAb only slightly delayed survival of cardiac allografts in this fully MHC-mismatched model, it significantly prolonged graft survival in combination with single-dose CTLA4-Ig or in CD28 knockout recipients. The prolongation of allograft survival was associated with Th2 polarization and a decrease in Th1 and granzyme B-producing cytotoxic T cells. The survival benefit of Delta1 blockade was abrogated after IL-4 neutralization and in STAT6KO recipients, but was maintained in STAT4KO recipients, reinforcing the key role of Th2 cell development in its graft-prolonging effects. To our knowledge, these data demonstrate for the first time an important role of Delta1 in alloimmunity, identifying Delta1 ligand as a potential novel target for immunomodulation in transplantation.
