NOTCH3 Antibody

Shipped with Ice Packs
In Stock

Product Specs

Buffer
PBS with 0.02% Sodium Azide, 50% Glycerol, pH 7.3. Store at -20°C. Avoid freeze/thaw cycles.
Lead Time
Typically, we can ship products within 1-3 business days after receiving your order. Delivery times may vary depending on the purchasing method or location. Please consult your local distributors for specific delivery time estimates.
Synonyms
CADASIL antibody; CASIL antibody; NOTC3_HUMAN antibody; Notch 3 antibody; Notch 3 intracellular domain antibody; Notch homolog 3 antibody; Notch3 antibody
Target Names
Uniprot No.

Target Background

Function
NOTCH3 functions as a receptor for membrane-bound ligands Jagged1, Jagged2, and Delta1. It plays a crucial role in regulating cell fate determination. Upon ligand activation, Notch3 releases the intracellular domain (NICD), which forms a transcriptional activator complex with RBPJ/RBPSUH, ultimately activating genes at the enhancer of split locus. This intricate process influences the implementation of differentiation, proliferation, and apoptotic programs within cells.
Gene References Into Functions
  • NOTCH3 is aberrantly expressed in pathological tumor vascularization, where it limits tumor angiogenesis through a pro-apoptotic activity. PMID: 28719575
  • TGFbeta activates the transcription factor ZEB1 to repress Notch3, thereby limiting terminal differentiation. PMID: 29170450
  • A novel NOTCH3 pathogenic variant (p.N1969 *) in the intracellular ankyrin repeat domain has been identified in three CADASIL patients. PMID: 29980472
  • SIRT6 may suppress cell proliferation, migration, and invasion by inhibiting the NOTCH3 signaling pathway in glioma. PMID: 29659670
  • Notch3 appears to be a promising target for gene therapy. DAPT can mediate a strong antitumor effect in nonsmall cell lung cancer (NSCLC) cells that overexpress Notch3. Further studies of a combined treatment regimen with DAPT and GEM are warranted and may provide greater efficacy and safety in the treatment of NSCLC patients. PMID: 29781034
  • While adult-onset Mendelian leukodystrophy genes are not commonly implicated in Alzheimer's disease, there is a potential pathogenic link between NOTCH3, CSF1R, and sporadic late-onset Alzheimer's disease. PMID: 29544907
  • Vascular smooth muscle cells were cyclically stretched on flexible membranes. Expression of Jagged1, Notch3, and target genes was down-regulated with strain. Upon increasing thickness, the model predicted a switch-type behavior of Notch signaling state with a steep transition of synthetic toward contractile VSMCs at a certain thickness. The Notch response to hemodynamics plays an important role in vascular homeostasis. PMID: 29610298
  • A threshold level of NFATc1 activity facilitates thymocyte differentiation and opposes Notch3-driven leukemia development. PMID: 27312418
  • A CADASIL family with a novel R110C mutation in the NOTCH3 gene has been described. PMID: 29363903
  • The levels of markers related to PaSC activation, such as a-smooth muscle actin (alpha-SMA), collagen I, and fibronectin, decreased in response to Notch3 knockdown, indicating that Notch3 plays a significant role in PaSC activation. Inhibition of PaSC activation via Notch3 siRNA reduced the proliferation and migration of PaSC-induced mouse pancreatic cancer (LTPA) cells. PMID: 29304760
  • The novel variant c.128G>C in exon 2 of NOTCH3 was identified in two patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. PMID: 28867359
  • Temozolomide (TMZ)-mediated gene expression profiles and networks are involved in inducing glioblastoma cell death. Increased CHAC1 and reduced Notch3 levels are both significantly involved in TMZ-mediated cytotoxicity. The TMZ-regulated CHAC1 pathway inhibits Notch3 activation, resulting in attenuation of Notch3-mediated signaling pathways. PMID: 27986595
  • These findings broaden the mutational and clinical spectrum of CADASIL and provide additional evidence for the existence of founder effect in CADASIL patients. PMID: 28710804
  • Our study suggested that the anti-neoplasm effect of mangiferin might be mediated through the regulation of Notch3. By targeting cell apoptosis pathways and enhancing the response to cisplatin treatment, mangiferin may represent a potential new drug for the treatment of human ovarian cancer. PMID: 28714011
  • Results found that Notch3 was more highly expressed in human urothelial cancer tissues than in non-tumorous bladder tissue samples. Notch3 overexpression was associated with poor clinical outcome, suggesting that Notch3 overexpression promotes growth and chemoresistance in urothelial cancer. PMID: 28416766
  • Two heterozygous missense mutations in the NOTCH3 gene have been identified in two families affected with cerebral autosomal dominant arteriopathy with subcortical infarct and leucoencephalopathy. PMID: 29188607
  • Results identified NOTCH3 as a direct target of MIR-613, which represses notch3 expression via targeting its 3'TUR. Conversely, HOTAIR positively regulates the notch3 expression by acting as a competing endogenous RNA for miR-613 binding in pancreatic cancer. PMID: 28415631
  • The present study identified a novel variant (chr19:15288426A>C) in the NOTCH3 gene using whole exome sequencing and confirmed it using Sanger sequencing. With multiple in silico analyses and 3D structure simulation, it is suggested that this variant has mildly damaging effects on the function of NOTCH3 gene, but can decrease protein stability. PMID: 28440410
  • We find that across species, the atypical receptor NOTCH3 is differentially overexpressed; it is progressively up-regulated with disease development and promotes tumor cell survival via activation of PI3k-Akt. PMID: 27791012
  • A rare pathogenic mutation on exon 14 of the NOTCH3 gene has been reported in a Chinese family affected by CADASIL. PMID: 27781952
  • The SNPs rs1044009 and rs1044006 in the NOTCH3 gene were associated with the risk of cerebral infarction disease in a Chinese Han agedness population. PMID: 27370894
  • Oligodendrocytes expressing mutant NOTCH3(R90C) (present in CADASIL disease), exhibited aberrant NOTCH3 proteolytic processing. These cells were less viable and had a higher rate of apoptosis. Cells with NOTCH3(R90C) had higher levels of intrinsic mitochondrial apoptosis, extrinsic death receptor path-related apoptosis, and autophagy compared with cells transfected with wild-type NOTCH3. PMID: 28601945
  • Novel variants in NOTCH3 associated with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy have been identified. PMID: 27881154
  • NOTCH3 single-nucleotide polymorphisms play a role in susceptibility to non-small cell lung cancer. PMID: 28968839
  • Single-nucleotide polymorphism in the NOTCH3 gene is associated with breast cancers. PMID: 28775167
  • Reduced NOTCH3/NICD3 and NOTCH4/NICD4 in miR-96- and miR-183-expressing nasopharyngeal carcinoma (NPC) cells suggest the involvement of the NOTCH signaling pathway in their tumor suppressive function. PMID: 27431799
  • Low Notch3 expression is associated with left ventricle hypertrabeculation/non-compaction and Menetrier-like gastropathy. PMID: 28013292
  • High NOTCH3 expression is associated with basal breast cancer. PMID: 28108512
  • In silico gene expression analysis of human T-ALL samples observed a significant correlation between Pin1 and Notch3 expression levels, which may further suggest a key role of the newly identified Notch3-Pin1 axis in T-cell Acute Lymphoblastic Leukemia (T-ALL) aggressiveness and progression. Thus, combined suppression of Pin1 and Notch3 proteins may be exploited as an additional target therapy for T-ALL. PMID: 26876201
  • MicroRNA-136 inhibits cancer stem cell activity and enhances the anti-tumor effect of paclitaxel against chemoresistant ovarian cancer cells by targeting the Notch3 pathway. PMID: 27887917
  • Specific Notch3 and Jag1 subcellular localization patterns may provide clues for the behavior of the corresponding tumors and could potentially be applied in the clinic for Jag1 targeting in triple-negative breast cancer patients. PMID: 28476798
  • There is a cross-talk between Jagged1/Notch3 and VEGF in TNBC angiogenesis. Jagged1/Notch3 is expected to be an important signaling pathway for TNBC progression and a potential target for TNBC neovascularization therapy. PMID: 28625320
  • Mutations in the NOTCH3 gene are associated with T-cell acute lymphoblastic leukemia. PMID: 27717083
  • Loss of Notch3 expression may be fundamental to the process of dedifferentiation that accompanies thyroid oncogenesis. Conversely, activation of Notch3 in thyroid cancer exerts an antiproliferative effect and restores elements of a differentiated phenotype. PMID: 27861750
  • Notch3 and pS6 are significantly related to ovarian epithelial cancer development and prognosis, and their combination represents a potential biomarker and therapeutic target in ovarian tumor angiogenesis. PMID: 27445438
  • NOTCH3 381C>T and 1735T>C polymorphisms were associated with Ischemic Stroke and might be risk factors for Ischemic Stroke development, but not NOTCH3 605C>T polymorphism. PMID: 27770607
  • This meta-analysis did not show significant associations between polymorphisms of NOTCH3 genes and Ischemic stroke. PMID: 27266621
  • This study showed that CADASIL with a Novel NOTCH3 Cys323Trp Mutation Presenting Border-Zone Infarcts. PMID: 27241575
  • Methylation of Notch3 modulates chemoresistance via P-glycoprotein. PMID: 27780727
  • Notch3 gene expression is up-regulated by Hepatitis B virus X protein in liver cancer cells. PMID: 27840976
  • The mRNA and protein expression of NOTCH3 was significantly lower in cisplatin and astragaloside IV-treated cells. PMID: 28281965
  • About one third of oral squamous cell carcinomas showed NOTCH3 expression in cancer-associated fibroblasts; this expression significantly correlated with tumor size. PMID: 27124156
  • Overexpression of Notch3 significantly reversed the tumor-suppressive effects of miR491-5p. This study reveals a mechanistic link between miR-491-5p and Notch3 in the pathogenesis of nasopharyngeal carcinoma. PMID: 27035429
  • Kaplan-Meier curves suggested that high expression of Notch3 was a significant risk factor for shortened survival time. Inhibition of Notch3 had an antiinvasion role in PDAC cells. In vitro, the inhibition of Notch3 reduced the migration and invasion capabilities of PDAC cells. PMID: 27633819
  • Data support a crucial role of Notch3 in the increase of stem-like property in NSCLC cells that might be associated with upregulation of ALDH1A1 and CD44 and activation of autophagy. PMID: 27035162
  • Jagged1 activation of Notch3 resulted in a significant decrease in cell proliferation while concomitantly promoting Hemangioma-pericyte maturation. PMID: 27941324
  • Results found new NOTCH3 missenses mutations in patients with pulmonary hypertension that were predicted to be likely pathogenic. PMID: 26894465
  • A Polish family with a previously unreported novel mutation in exon 12 c.1851C>C/G of the NOTCH3 gene and varying disease expression has been presented. One of the two family members with the confirmed mutation presented with all the main CADASIL symptoms; while, his affected father was nearly asymptomatic. PMID: 27375140
  • Overexpressing Notch3 protein upregulated Cdh1 expression and resulted in p27(Kip) accumulation by accelerating Skp2 degradation. PMID: 26694515
  • A rare 2182C>T mutation in exon 14 of the NOTCH3 gene was identified in all available cases. PMID: 27455010
Database Links

HGNC: 7883

OMIM: 125310

KEGG: hsa:4854

STRING: 9606.ENSP00000263388

UniGene: Hs.8546

Involvement In Disease
Cerebral arteriopathy, autosomal dominant, with subcortical infarcts and leukoencephalopathy, 1 (CADASIL1); Myofibromatosis, infantile 2 (IMF2); Lateral meningocele syndrome (LMNS)
Protein Families
NOTCH family
Subcellular Location
Cell membrane; Single-pass type I membrane protein.; [Notch 3 intracellular domain]: Nucleus. Note=Following proteolytical processing NICD is translocated to the nucleus.
Tissue Specificity
Ubiquitously expressed in fetal and adult tissues.

Q&A

What are the primary types of NOTCH3 antibodies available for research?

Researchers primarily categorize NOTCH3 antibodies based on their functional effects on Notch signaling:

  • Agonist antibodies: These activate NOTCH3 signaling by binding to the Negative Regulatory Region (NRR) of the receptor. The A13 agonist antibody is a well-characterized example that induces activation of both wild-type and mutant NOTCH3 receptors by destabilizing the receptor's NRR in a ligand-independent manner .

  • Inhibitory antibodies: These suppress NOTCH3 signaling by stabilizing the quiescent conformation of the NRR, preventing the conformational changes necessary for receptor activation. Examples include MOR20350, MOR20358, MOR20337, and A4, which have been shown to inhibit both ligand-dependent and ligand-independent NOTCH3 signaling .

  • Non-inhibitory antibodies: These bind to NOTCH3 without affecting its signaling function. These antibodies (such as the anti-N3 described in some studies) are particularly valuable for antibody-drug conjugate development and imaging applications .

  • Detection antibodies: Specialized antibodies that recognize specific epitopes, including neo-epitopes created by proteolytic processing of NOTCH3. A notable example is the antibody that specifically detects the intracellular domain of NOTCH3 (ICD3) generated after gamma-secretase cleavage .

Each antibody type serves distinct research purposes, from pathway modulation to biomarker detection, making them essential tools in NOTCH3 biology investigations.

How do NOTCH3 agonist antibodies activate signaling at the molecular level?

NOTCH3 agonist antibodies activate signaling through a well-defined molecular mechanism:

  • NRR binding and destabilization: Agonist antibodies like A13 target the Negative Regulatory Region (NRR) of NOTCH3, which normally maintains the receptor in an autoinhibited conformation. When A13 binds to this region, it destabilizes the autoinhibitory structure .

  • Exposure of cleavage sites: This destabilization exposes the S2 cleavage site, making it accessible to metalloproteases like ADAM10/17, even in the absence of ligand binding .

  • Proteolytic processing: Following S2 cleavage, the gamma-secretase complex can then cleave the receptor at the S3 site, releasing the NOTCH3 intracellular domain (ICD3) .

  • Nuclear translocation and transcriptional activation: The released ICD3 translocates to the nucleus where it forms a transcriptional activation complex with CSL/RBP-Jκ and co-activators to regulate target gene expression .

Experimental evidence demonstrates that both the intact A13 antibody and its Fab fragment can stimulate ligand-independent signaling, though the Fab fragment shows slightly reduced efficacy compared to the intact antibody . The A13 antibody has been shown to increase the release of N3ECD (NOTCH3 extracellular domain) into cell culture supernatants, confirming its mechanism of action through NRR destabilization .

What distinguishes inhibitory from non-inhibitory NOTCH3 antibodies in terms of binding epitopes?

The functional difference between inhibitory and non-inhibitory NOTCH3 antibodies is largely determined by their specific binding epitopes:

Inhibitory antibodies:

  • Primarily bind to the NRR domain, specifically targeting regions critical for maintaining the autoinhibited conformation

  • The binding stabilizes the quiescent conformation of the NRR, preventing the conformational changes necessary for NOTCH3 activation

  • Examples like MOR20350 and MOR20358 bind epitopes that effectively lock the NRR in its closed state

  • These antibodies often compete with each other for binding, suggesting overlapping epitopes within the NRR

Non-inhibitory antibodies:

  • Often bind to regions outside the critical autoinhibitory elements

  • May bind to the ligand-binding domain (LBD) or other regions of the extracellular domain that don't directly influence receptor activation

  • Examples include antibodies like MOR20364 (anti-LBD) which bind to NOTCH3 but don't affect downstream signaling

  • The anti-N3 antibody described in some studies binds to the HD1 subdomain but doesn't inhibit signaling

Epitope mapping studies have revealed that inhibitory antibodies typically target structures within the NRR that are essential for maintaining the receptor in its inactive state, while non-inhibitory antibodies bind to epitopes that don't interfere with the conformational changes necessary for activation . This distinction is crucial for researchers selecting antibodies for specific experimental purposes.

How can researchers detect activated NOTCH3 using antibody-based approaches?

Detecting activated NOTCH3 is crucial for monitoring signaling activity. Researchers can employ several antibody-based approaches:

Neo-epitope specific antibodies:

  • Custom antibodies that specifically recognize the neo-epitope created by gamma-secretase cleavage between amino acids G1661 and V1662 of human NOTCH3

  • These antibodies selectively detect the intracellular domain of NOTCH3 (ICD3) and don't cross-react with other Notch receptors (like ICD1)

  • Detection by Western blotting reveals a band that disappears upon treatment with gamma-secretase inhibitors like DAPT

Validation approaches:

  • Treatment with gamma-secretase inhibitors (e.g., compound E or DAPT) should eliminate the ICD3 signal, confirming antibody specificity

  • Comparison with known NOTCH3-activated cell lines (e.g., TALL-1 cells with S1580L mutation) can serve as positive controls

  • Cell lines with NOTCH1 but not NOTCH3 activation (e.g., RPMI-8402) can serve as negative controls

In situ detection methods:

  • In situ hybridization (ISH) assays can be used to quantitate NOTCH3 expression in tumor samples

  • Image-based analysis can quantify the percentage of NOTCH3-positive ISH staining

  • This approach allows classification of samples into expression categories (low, moderate, high)

Correlation with downstream signaling:

  • Monitoring Notch target genes (DTX1, HES1, NOTCH3, PTCRα) provides functional validation of NOTCH3 activation

  • Changes in these target genes should correlate with ICD3 detection to confirm functional significance

When implementing these detection methods, researchers should include appropriate controls to ensure specificity for NOTCH3 over other Notch receptors, particularly in systems where multiple Notch receptors may be active.

What are the recommended experimental conditions for studying NOTCH3 antibody internalization and trafficking?

Studying NOTCH3 antibody internalization and trafficking requires careful experimental design:

Pulse-chase analysis with confocal microscopy:

  • Label antibodies with fluorescent tags that won't interfere with binding properties

  • Perform initial pulse binding at 4°C to allow surface binding without internalization

  • Shift to 37°C to trigger internalization during the chase period

  • Optimal time points: 0h, 1h, 2h, 4-5h, and 24h to capture the full internalization kinetics

  • Cell lines with documented NOTCH3 expression (e.g., MDA-MB-468) are recommended

Live-cell imaging for real-time dynamics:

  • Directly label different NOTCH3 antibodies with distinct fluorescent dyes

  • Co-incubate cells with multiple antibody types simultaneously to compare trafficking patterns

  • Capture images at regular intervals (e.g., every 15-30 minutes for up to 4-6 hours)

  • This approach reveals differential clustering and internalization kinetics between agonist and non-agonist antibodies

Controls and validation:

  • Include NOTCH3 siRNA knockdown controls to confirm binding specificity

  • Compare internalization patterns between signaling-inhibitory and non-inhibitory antibodies

  • For antibody-drug conjugates, correlate internalization patterns with therapeutic efficacy

Quantification methods:

  • Measure the formation of punctate structures over time

  • Quantify the ratio of membrane-bound versus internalized antibody

  • Track colocalization with endosomal/lysosomal markers to confirm trafficking pathway

Research has shown that inhibitory antibodies (like anti-N3(i)) exhibit faster clustering and internalization compared to non-inhibitory antibodies (like anti-N3). By 4-5 hours, inhibitory antibodies typically show pronounced punctate structures, while non-inhibitory antibodies maintain a more uniform membrane distribution .

How can researchers effectively use NOTCH3 antibodies in reporter assay systems?

NOTCH3 antibody activity can be reliably measured using various reporter assay systems:

Luciferase-based reporter assays:

  • TP1-Luciferase reporter system: Based on the Epstein Barr virus terminal protein 1 (TP1) promoter, which contains CSL/RBP-Jκ binding sites and responds to Notch activation

  • Transfect cells expressing NOTCH3 (wild-type or mutant) with the TP1-Luciferase reporter construct

  • Treat with NOTCH3 antibodies (agonist or inhibitory) and measure luciferase activity

  • This system effectively detects both ligand-dependent and ligand-independent NOTCH3 activation

Co-culture systems for ligand-dependent activation:

  • Create isogenic cell lines expressing NOTCH3 receptor and corresponding ligand (e.g., Jagged1) under inducible promoters

  • Co-culture receptor-expressing cells (transfected with reporter) with ligand-expressing cells

  • Measure reporter activity in the presence or absence of NOTCH3 antibodies

  • This approach allows assessment of antibody effects on ligand-dependent signaling

Cell line considerations:

  • Use TET-inducible expression systems to ensure comparable expression levels between wild-type and mutant receptors

  • HEK293 cells are commonly used for transfection-based assays

  • T-ALL lines with known NOTCH3 activation (e.g., TALL-1) serve as valuable positive controls

Controls and validation:

  • Include gamma-secretase inhibitors (e.g., compound E, DAPT) as positive controls for Notch inhibition

  • Compare antibody effects on wild-type versus mutant NOTCH3 (e.g., C455R CADASIL mutation)

  • Use cell lines with NOTCH1 but not NOTCH3 activation as negative controls

  • Correlate reporter assay results with measurements of N3ECD release for agonist antibodies

This systematic approach enables quantitative assessment of how different NOTCH3 antibodies modulate receptor signaling, crucial for both basic research and therapeutic antibody development.

How effective are NOTCH3 agonist antibodies in treating small vessel disease models?

NOTCH3 agonist antibodies have shown promising efficacy in small vessel disease (SVD) models, particularly those related to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy):

Experimental evidence:

  • In mouse models expressing the C455R CADASIL mutation, which strongly abrogates Notch3 signaling, the A13 agonist antibody successfully activated both wild-type and mutant NOTCH3 receptors

  • Treatment restored mural cell coverage in retinal arteries and arterioles, a key pathological feature of SVD

  • The antibody activated ligand-insensitive mutant Notch3 receptors in vitro, demonstrating its potential to bypass the signaling defect in CADASIL

Biomarker modulation:

  • Treatment with the A13 agonist antibody increased plasma levels of N3ECD (NOTCH3 extracellular domain) and endostatin/collagen 18α1 in mouse models

  • These biomarkers serve as sensitive surrogate markers of Notch3 activity in vivo

  • The biomarker modulation correlated with morphological improvement in vascular structures

Mechanism of therapeutic action:

  • The agonist antibody bypasses the need for ligand binding by directly destabilizing the receptor's NRR

  • This leads to exposure of the S2 cleavage site and subsequent proteolytic processing

  • The approach is particularly valuable for CADASIL mutations that render the receptor insensitive to ligand activation

What role do NOTCH3 antibodies play in cancer research, particularly for T-cell acute lymphoblastic leukemia (T-ALL)?

NOTCH3 antibodies serve multiple critical functions in cancer research, especially for T-ALL:

Diagnostic applications:

  • Neo-epitope specific antibodies detecting the activated form of NOTCH3 (ICD3) help identify cancers with ongoing NOTCH3 activation

  • Screening of 40 primary T-ALL tumors and 24 patient-derived xenograft (PDX) models identified two primary tumors and 12 PDX models with evidence of NOTCH3 activation

  • This approach enables identification of cancers likely to respond to NOTCH3-targeted therapies

Therapeutic targeting:

  • Inhibitory antibodies targeting the NOTCH3 NRR (such as MOR20350 and MOR20358) effectively suppress NOTCH3 signaling in T-ALL cell lines with activating NOTCH3 mutations

  • These antibodies reduce expression of Notch target genes (DTX1, HES1, NOTCH3, PTCRα) comparable to gamma-secretase inhibitor treatment

  • The specificity for NOTCH3 (versus NOTCH1) allows selective targeting in cancers where NOTCH3 drives oncogenesis

Characterization of activating mutations:

  • NOTCH3 antibodies have helped identify and characterize activating mutations in the NRR and PEST domains

  • The TALL-1 cell line harbors an S1580L mutation in the NRR that leads to ligand-independent receptor activation, detectable with ICD3-specific antibodies

  • These mutations provide important insights into mechanisms of NOTCH3-driven oncogenesis

Development of combination approaches:

  • Antibody-drug conjugates targeting NOTCH3 have shown promise in cancer models

  • The inhibitory properties of some NOTCH3 antibodies may be combined with direct cytotoxic effects through drug conjugation

  • This dual approach could potentially overcome resistance mechanisms

NOTCH3 antibodies thus provide valuable tools for both basic research into NOTCH3-driven cancer mechanisms and for developing targeted therapeutic approaches for cancers with aberrant NOTCH3 signaling.

How can NOTCH3 antibodies reverse skeletal phenotypes in disease models?

Research has demonstrated that NOTCH3 antibodies can effectively reverse skeletal phenotypes in specific disease models:

Model system and phenotypic characteristics:

  • The Notch3tm1.1Ecan mouse model reproduces functional aspects of mutations found in Lateral Meningocele Syndrome (LMS)

  • This model features a truncated NOTCH3 protein of 2230 amino acids lacking the PEST domain

  • Heterozygous mice exhibit increased osteoclast numbers, enhanced bone remodeling, and osteopenia

Antibody intervention approach:

  • Treatment with an anti-Notch3 NRR antibody selectively inhibits signaling through the Notch3 receptor

  • The antibody works by stabilizing the quiescent conformation of the NRR

  • This approach determines whether persistent Notch3 signaling is necessary to maintain the phenotype

Experimental design:

  • Notch3tm1.1Ecan mice and control littermates were administered either anti-Notch3 NRR antibody or a non-targeting isotype control antibody (anti-ragweed)

  • Bone microarchitectural analysis was performed to evaluate skeletal phenotype

Results:

  • The anti-Notch3 NRR antibody was effective in reversing the cancellous bone osteopenia of Notch3tm1.1Ecan male mice

  • This demonstrates that persistent Notch3 signaling is necessary to maintain the skeletal phenotype

How do different NOTCH3 mutations affect antibody binding and efficacy?

NOTCH3 mutations can significantly impact antibody binding and efficacy, creating complex considerations for therapeutic development:

CADASIL mutations in the NRR:

  • The C455R mutation strongly abrogates Notch3 signaling by rendering the receptor insensitive to ligand activation

  • Despite this, the A13 agonist antibody can still activate the C455R mutant receptor by bypassing the ligand-dependent activation mechanism

  • This suggests agonist antibodies target structural elements that remain accessible even in NRR mutations

NOTCH3 truncating mutations:

  • In models like Notch3tm1.1Ecan (reproducing aspects of Lateral Meningocele Syndrome), the NOTCH3 protein lacks the PEST domain

  • Anti-Notch3 NRR antibodies remain effective in these models, suggesting the NRR domain remains structurally intact and accessible

  • The efficacy indicates that PEST domain mutations don't significantly alter the conformation of the NRR

Oncogenic NOTCH3 mutations:

  • Activating mutations in the NRR (like S1580L found in TALL-1 cells) result in ligand-independent activation

  • Inhibitory antibodies targeting the NRR can still suppress this aberrant activation

  • These findings suggest that even constitutively active mutants maintain structural elements recognized by inhibitory antibodies

Epitope accessibility considerations:

  • Different mutations may alter the accessibility of specific epitopes

  • Researchers should validate antibody binding to the specific mutants under study

  • Epitope mapping and structural studies can help predict which antibodies will remain effective against specific mutations

This complex relationship between mutations and antibody efficacy underscores the importance of personalized approaches in NOTCH3-targeted therapies. Researchers should characterize both the specific mutation and antibody epitope when developing therapeutic strategies for NOTCH3-related diseases.

What biomarkers can be used to monitor NOTCH3 antibody efficacy in vivo?

Several biomarkers have been validated for monitoring NOTCH3 antibody efficacy in vivo:

N3ECD (NOTCH3 extracellular domain):

  • Released into plasma/serum following receptor activation

  • Levels increase in response to agonist antibody treatment

  • Correlates with increased Notch3 signaling activity

  • Can be measured by ELISA in cell culture supernatants and plasma

  • Particularly sensitive for monitoring agonist antibody effects

Endostatin/collagen 18α1:

  • Regulated by Notch3 transcriptional activity

  • Plasma levels change in response to altered Notch3 signaling

  • Age-dependent patterns: reduced in young (100-day-old) C455R mice, increased in older (6-month-old) C455R mice

  • Increases in young C455R mice treated with Notch3 agonist antibodies

  • Serves as a downstream indicator of restored Notch3 signaling

HTRA1 and IGFBP-1:

  • Altered in some Notch3 mutant models (like C455R mice)

  • Show variable responses to Notch3 antibody treatment

  • May be useful as secondary markers in specific disease contexts

  • Less consistent than N3ECD for monitoring antibody efficacy

Morphological markers:

  • Mural cell coverage in retinal arteries and arterioles

  • Direct visualization of vascular integrity

  • Strongly correlates with Notch3 signaling status

  • Requires tissue analysis rather than blood sampling

  • Essential endpoint for confirming functional outcomes beyond biochemical changes

For optimal monitoring of antibody efficacy, researchers should employ multiple biomarkers simultaneously, ideally combining circulating biomarkers (N3ECD, endostatin/collagen 18α1) with functional/morphological assessments where possible. Statistical correlation analysis between biomarkers and functional outcomes can help establish the most reliable predictors of therapeutic efficacy in specific disease models.

What are the key considerations when developing NOTCH3 antibody-drug conjugates (ADCs)?

Developing effective NOTCH3 antibody-drug conjugates (ADCs) requires careful consideration of several critical factors:

Antibody selection criteria:

  • Internalization efficiency: Select antibodies that demonstrate robust and rapid internalization after binding to NOTCH3

  • Signaling effects: Consider whether inhibitory or non-inhibitory antibodies are preferable for the specific disease context

  • Binding domain specificity: Antibodies binding to different domains may exhibit distinct internalization and trafficking patterns

  • Binding kinetics: Antibodies with higher affinity may not necessarily show better internalization

Cell-membrane distribution patterns:

  • Non-inhibitory antibodies (like anti-N3) typically show uniform cell-membrane distribution initially

  • Inhibitory antibodies (like anti-N3(i)) tend to induce clustering and more rapid internalization

  • After 4-5 hours, inhibitory antibodies form large membrane and intracellular punctate structures, while non-inhibitory antibodies show fewer puncta

  • These distinct trafficking patterns impact ADC efficacy and should guide antibody selection

Target expression assessment:

  • Develop reliable quantification methods like in situ hybridization (ISH) to assess NOTCH3 expression

  • Stratify tumors into expression categories (low, moderate, high) based on NOTCH3 levels

  • Validate expression data using multiple techniques (qRT-PCR, ISH, protein detection)

  • Expression heterogeneity within tumors must be considered for effective targeting

Conjugate design optimization:

  • Select cytotoxic payloads appropriate for the cell type and disease

  • Optimize linker chemistry for stability in circulation but efficient release after internalization

  • Determine optimal drug-to-antibody ratio for maximal efficacy while maintaining favorable pharmacokinetics

  • Consider the impact of the conjugation method on antibody binding properties

Validation approaches:

  • Confirm specific binding to NOTCH3 using knockdown approaches (e.g., siRNA)

  • Compare the efficacy of different ADCs against standard-of-care chemotherapy

  • Evaluate sustained tumor regressions rather than just growth inhibition

  • Assess potential toxicities in normal tissues expressing NOTCH3

These considerations are essential for developing NOTCH3-targeted ADCs with optimal therapeutic potential while minimizing off-target effects.

What are the optimal experimental controls when testing NOTCH3 antibody specificity and function?

Rigorous experimental controls are essential when evaluating NOTCH3 antibody specificity and function:

Genetic controls:

  • NOTCH3 knockdown/knockout: siRNA knockdown or CRISPR-mediated knockout of NOTCH3 to confirm antibody binding specificity

  • Isogenic cell lines: Compare cell lines with defined NOTCH3 expression levels (negative, low, medium, high)

  • Mutant NOTCH3 variants: Include cells expressing known NOTCH3 mutations (e.g., C455R, S1580L) to assess antibody performance with altered receptor conformations

Pharmacological controls:

  • Gamma-secretase inhibitors (GSIs): Compounds like DAPT or compound E to block Notch cleavage and activation

  • Ligand modulation: Inducible expression of Notch ligands (e.g., Jagged1) to control ligand-dependent activation

  • Blocking peptides: Specific peptides corresponding to the antibody epitope can confirm binding specificity

Antibody-specific controls:

  • Isotype control antibodies: Non-targeting antibodies (e.g., anti-ragweed) with the same isotype as the test antibody

  • Fab fragments: Compare full antibodies versus Fab fragments to assess potential effects of bivalent binding

  • Epitope competition: Use multiple antibodies targeting different or overlapping epitopes to confirm specificity

Cross-reactivity controls:

  • Other Notch receptors: Test effects on cells expressing NOTCH1, NOTCH2, or NOTCH4 to confirm NOTCH3 specificity

  • Multiple cell types: Validate findings across different cell lines to ensure consistent antibody performance

  • Species specificity: Determine whether antibodies recognize NOTCH3 from different species (human vs. mouse)

Functional readout controls:

  • Reporter assays: Include positive and negative controls in transcriptional reporter assays

  • Target gene expression: Monitor multiple Notch target genes (DTX1, HES1, NOTCH3, PTCRα) to confirm pathway effects

  • Biomarker panels: Measure multiple biomarkers (N3ECD, endostatin/collagen 18α1) to strengthen confidence in functional effects

Implementing these comprehensive controls ensures reliable interpretation of NOTCH3 antibody experiments and facilitates comparison across different research studies.

How do different experimental models affect NOTCH3 antibody performance and interpretation?

The experimental model significantly impacts NOTCH3 antibody performance and data interpretation, creating important considerations for researchers:

Cell line models:

  • Endogenous vs. overexpression: Cell lines with endogenous NOTCH3 expression (like MDA-MB-468) may show different antibody responses compared to overexpression systems

  • Inducible systems: TET-inducible expression systems provide better control over expression levels but may not recapitulate natural regulation

  • HEK293 cells: Commonly used for transfection-based assays but lack the relevant tissue context

  • T-ALL lines (e.g., TALL-1): Provide disease-relevant context for oncogenic NOTCH3 signaling

In vivo models:

  • CADASIL models (C455R mice): Allow assessment of vascular phenotypes relevant to small vessel disease

  • Notch3tm1.1Ecan mice: Model aspects of Lateral Meningocele Syndrome with skeletal phenotypes

  • Xenograft models: Patient-derived xenografts maintain tumor heterogeneity but lack immune components

  • Species differences: Human-specific antibodies may not recognize mouse NOTCH3, requiring humanized models

Primary tissue considerations:

  • Expression heterogeneity: NOTCH3 expression varies within and between patient samples, affecting antibody efficacy

  • Tissue-specific effects: NOTCH3 signaling consequences differ between vascular, skeletal, and cancer contexts

  • Ex vivo systems: Primary patient samples in short-term culture may better preserve signaling context

  • Biomarker accessibility: Some biomarkers may be measurable in blood, while others require tissue access

Technical variables affecting interpretation:

  • Antibody concentration: Dose-response relationships vary between models

  • Treatment duration: Acute vs. chronic treatment may yield different outcomes

  • Route of administration: In vivo delivery method affects biodistribution

  • Analysis timing: Early vs. late timepoints may reveal different aspects of antibody effects

When designing NOTCH3 antibody studies, researchers should carefully select models that best represent the disease context of interest, validate findings across multiple models when possible, and consider how model-specific factors might influence antibody performance and data interpretation.

What techniques provide the most reliable structural information about NOTCH3 antibody binding?

Understanding the structural basis of NOTCH3 antibody binding requires sophisticated techniques that provide complementary insights:

X-ray crystallography:

  • Co-crystal structures: Provides the highest resolution data on antibody-antigen interfaces

  • Successfully used to determine the first co-crystal structure of a NOTCH3 antibody with the NRR protein

  • Reveals precise epitope binding sites and potential conformational changes

  • Can define distinct epitopes for different NRR antibodies

  • Limitations include challenges in crystallizing membrane proteins and capturing dynamic interactions

Hydrogen-exchange mass spectrometry (HX-MS):

  • Compares HX-MS patterns of the NOTCH3 NRR in the presence and absence of antibodies

  • Reveals regions where antibody binding affects solvent accessibility

  • Provides insights into how antibodies overcome Notch3 autoinhibition

  • Particularly valuable for understanding dynamic conformational changes

  • Complementary to static structural methods like crystallography

Epitope binning and competition assays:

  • Determines whether different antibodies compete for binding

  • Helps group antibodies into bins with similar epitopes

  • For example, demonstrating that anti-N3(i) effectively competes against anti-N3 for binding to NOTCH3

  • Can be performed using techniques like biolayer interferometry or flow cytometry

  • Provides functional grouping without atomic-level detail

Mutational mapping:

  • Systematic mutation of receptor residues to identify those critical for antibody binding

  • Can map epitopes when structural data is unavailable

  • Particularly useful for comparing binding sites of inhibitory vs. non-inhibitory antibodies

  • Can be combined with functional assays to correlate epitope with activity

  • Limited by potential confounding effects of mutations on receptor conformation

Computational modeling:

  • Molecular dynamics simulations can predict antibody-antigen interactions

  • Docking algorithms help model potential binding modes

  • Structure-based design can guide antibody engineering

  • Most valuable when integrated with experimental validation

  • Accuracy depends on quality of initial structural data

For comprehensive understanding, researchers should combine multiple techniques - using crystallography or HX-MS to define precise binding modes, complemented by epitope binning and mutational analyses to connect structural insights with functional effects.

Quick Inquiry

Personal Email Detected
Please use an institutional or corporate email address for inquiries. Personal email accounts ( such as Gmail, Yahoo, and Outlook) are not accepted. *
© Copyright 2025 TheBiotek. All Rights Reserved.