title: Generation of anti-Notch antibodies and their application in blocking Notch signalling in neural stem cells.
abstract: Notch signalling occurs via direct cell-cell interactions and plays an important role in linking the fates of neighbouring cells. There are four different mammalian Notch receptors that can be activated by five cell surface ligands. The ability to inhibit specific Notch receptors would help identify the roles of individual family members and potentially provide a means to study and control cell differentiation. Anti-Notch antibodies in the form of single chain Fvs were generated from an antibody phage display library by selection on either the ligand binding domain or the negative regulatory region (NRR) of Notch1 and Notch2. Six antibodies targeting the NRR of Notch1 and four antibodies recognising the NRR of Notch2 were found to prevent receptor activation in cell-based luciferase reporter assays. These antibodies were potent, highly specific inhibitors of individual Notch receptors and interfered with endogenous signalling in stem cell systems of both human and mouse origin. Antibody-mediated inhibition of Notch efficiently down-regulated transcription of the immediate Notch target gene hairy and enhancer of split 5 (Hes5) in both mouse and human neural stem cells and revealed a redundant regulation of Hes5 in these cells as complete down-regulation was seen only after simultaneous blocking of Notch1 and Notch2. In addition, these antibodies promoted differentiation of neural stem cells towards a neuronal fate. In contrast to the widely used small molecule γ-secretase inhibitors, which block all 4 Notch receptors (and a multitude of other signalling pathways), antibodies allow blockade of individual Notch family members in a highly specific way. Specific inhibition will allow examination of the effect of individual Notch receptors in complex differentiation schemes regulated by the co-ordinated action of multiple signalling pathways.
authors: University of Cambridge, Department of Biochemistry, Tennis Court Road, CB2 1QW Cambridge, UK.
authors: Ronny
authors: R
authors: Falk
authors: Anna
authors: A
authors: Falk
authors: Michael R
authors: MR
authors: Dyson
authors: Anna N
authors: AN
authors: Melidoni
authors: Kothai
authors: K
authors: Parthiban
authors: Joyce L
authors: JL
authors: Young
authors: Wendy
authors: W
authors: Roake
authors: John
authors: J
authors: McCafferty
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001665:Binding Sites; D002454:Cell Differentiation; D049109:Cell Proliferation; D061505:Cell Surface Display Techniques; D018920:Coculture Techniques; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D057809:HEK293 Cells; D006801:Humans; D049410:Luciferases, Renilla / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D058953:Neural Stem Cells / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051881:Receptor, Notch1 / Q000037:antagonists & inhibitors* / Q000276:immunology; D051883:Receptor, Notch2 / Q000037:antagonists & inhibitors; D015398:Signal Transduction; D057127:Single-Chain Antibodies / Q000096:biosynthesis* / Q000494:pharmacology; D059467:Transcriptome / Q000187:drug effects
chemical_list: C497761:NOTCH1 protein, human; C497762:Notch1 protein, mouse; D012333:RNA, Messenger; D051881:Receptor, Notch1; D051883:Receptor, Notch2; D057127:Single-Chain Antibodies; D049410:Luciferases, Renilla