TEL2 Antibody

What is TEL2 and why is it important in hematological research?

TEL2 (ETV7) is a member of the ETS family of transcription factors characterized by a highly conserved carboxy-terminal DNA binding domain. It functions as a transcriptional repressor that binds specifically to the DNA sequence 5′-CCGGAAGT-3′ . TEL2 is primarily expressed in hematopoietic tissues and plays crucial roles in:

• Regulation of B-cell proliferation and cell cycle progression

• Suppression of Myc-induced apoptosis

• B-cell immortalization processes

• Transcriptional regulation of key survival genes

The significance of TEL2 in hematological research stems from its cooperation with oncogenes like Myc in B-cell lymphomagenesis, with approximately one-third of B-ALL samples showing coordinated elevated expression of MYC/MYCN and TEL2 . This makes TEL2 a potential diagnostic and therapeutic target in B-cell malignancies, necessitating reliable antibodies for its detection and characterization.

What detection methods are compatible with commercially available TEL2 antibodies?

Commercial TEL2 antibodies have been validated for multiple detection techniques, offering researchers flexibility in experimental design. Current antibodies support the following applications:

Most commercial antibodies, such as the E-1 mouse monoclonal, are available in both non-conjugated forms and various conjugated formats including agarose, HRP, PE, FITC, and multiple Alexa Fluor® conjugates, allowing for versatility in experimental design . When selecting an antibody, researchers should consider the specific isoform they wish to detect, as alternative splicing results in seven known TEL2 isoforms (designated A-G) .

How can I verify the specificity of a TEL2 antibody in my experimental system?

Verifying antibody specificity is crucial for reliable results. For TEL2 antibodies, consider the following validation approach:

• Positive and negative controls: Use cell lines or tissues known to express high (hematopoietic tissues) and low levels of TEL2. Lymphoid cell lines are appropriate positive controls.

• Knockdown validation: Perform siRNA or shRNA-mediated knockdown of TEL2 in your experimental system and confirm reduced signal with the antibody.

• Peptide competition assay: Pre-incubate the antibody with the immunizing peptide (e.g., the C-terminal peptide DRIEFKDKRPEISP used in antibody production) before application to your sample . Signal reduction confirms specificity.

• Cross-reactivity testing: If working with mouse models, determine whether the antibody cross-reacts with mouse TEL2 or is human-specific, as many commercial antibodies are raised against the human protein .

• Isoform detection: Since TEL2 has multiple isoforms, use known molecular weight markers to confirm detection of the expected isoform (canonical form is approximately 39 kDa) .

How can TEL2 antibodies be used to investigate its role in B-cell proliferation and apoptosis?

TEL2's impact on B-cell proliferation and apoptosis can be comprehensively studied using antibodies in the following experimental approaches:

Cell cycle analysis protocol:

• Transduce B-cell progenitors with TEL2-expressing or control vectors

• Culture cells on S17 stromal cells with IL-7

• Remove cells from culture and fix for cell cycle analysis

• Stain with propidium iodide and analyze by flow cytometry

• Use TEL2 antibodies for co-staining to confirm expression levels in transduced cells

Research has shown that TEL2-expressing pro-B cells have an increased percentage of cells in S/G2/M phases (44.5% versus 33% for wild-type pro-B cells) . Following IL-7 and stromal support withdrawal, while 85% of wild-type pro-B cells arrest in G0, 39% of TEL2-expressing cells remain in S/G2/M phase after 24 hours .

Apoptosis assessment:

• Express TEL2 in Eμ-Myc bone marrow cells via retroviral transduction

• Measure apoptotic indices using Annexin-V staining after 5 days

• Confirm TEL2 expression levels via Western blot using specific antibodies

Studies have demonstrated that TEL2 expression reduces the apoptotic index of Eμ-Myc cells approximately twofold (from 30% to 15%) . Additionally, in standard B-cell culture conditions, TEL2-expressing pro-B cells show a threefold lower apoptotic index than wild-type or vector-transduced cells .

What are the optimal conditions for detecting nuclear TEL2 in immunofluorescence studies?

Detecting nuclear proteins like TEL2 requires careful optimization of immunofluorescence protocols:

• Fixation optimization: Use 4% paraformaldehyde for 15-20 minutes at room temperature. Over-fixation can mask nuclear epitopes.

• Permeabilization: A dual approach is recommended:

  • 0.2% Triton X-100 for 10 minutes for general permeabilization

  • Follow with a brief treatment with 0.5% SDS (1-2 minutes) to expose nuclear epitopes

• Blocking: Use 5% BSA with 0.1% Tween-20 in PBS for at least 1 hour

• Antibody dilution: Most TEL2 antibodies work optimally at 1:50 to 1:200 dilution; titration is recommended for each new lot

• Nuclear counterstaining: Use DAPI or Hoechst at standard concentrations, but avoid prolonged exposure that might quench TEL2 fluorescence

• Controls and co-localization: Include nuclear landmark proteins (e.g., lamin) as co-stains to confirm nuclear localization

Since TEL2 binds specifically to the DNA sequence 5′-CCGGAAGT-3′, periods of transcriptional activity may affect its nuclear distribution pattern . Consider time-course studies if investigating transcriptional dynamics.

How can I investigate the interaction between TEL2 and Myc using TEL2 antibodies?

Investigating TEL2-Myc interactions requires multifaceted approaches using TEL2 antibodies:

Co-immunoprecipitation protocol:

• Prepare nuclear extracts from cells expressing both TEL2 and Myc

• Perform immunoprecipitation using TEL2 antibody (preferably bound to agarose)

• Elute and analyze by Western blotting for both TEL2 and Myc

• Perform reciprocal IP with Myc antibody to confirm interaction

Proximity ligation assay (PLA):

• Fix cells expressing both proteins

• Incubate with primary antibodies against TEL2 and Myc

• Add PLA probes with complementary oligonucleotides

• Perform ligation and amplification according to standard PLA protocols

• Visualize interaction as fluorescent dots where proteins are in close proximity (<40 nm)

Chromatin immunoprecipitation (ChIP):

• Cross-link protein-DNA complexes in cells expressing TEL2 and Myc

• Sonicate to fragment chromatin

• Immunoprecipitate with TEL2 antibody

• Perform qPCR for known Myc target genes

Research has shown that TEL2 cooperates with Myc in B-cell lymphomas, and approximately one-third of B-ALL samples display coordinated elevated expression of MYC/MYCN and TEL2 . These techniques can help elucidate the molecular mechanisms underlying this cooperation.

Why might I observe variable TEL2 detection in Western blots of B-cell samples?

Variable detection of TEL2 in B-cell samples can result from several factors:

Biological variables:

• Developmental stage effects: TEL2 expression varies across B-cell development stages, with higher expression typically in pro-B and pre-B cells compared to mature B cells

• Activation state: B-cell activation may alter TEL2 expression; consider standardizing activation conditions

• Alternative splicing: TEL2 exists in at least seven isoforms (A-G) through alternative splicing , which may be differentially expressed

Technical considerations:

• Extraction method: Nuclear extraction efficiency can significantly impact TEL2 detection. Use specialized nuclear extraction buffers with DNase treatment.

• Sample preparation: TEL2 is susceptible to degradation; use fresh protease inhibitors and keep samples cold.

• Antibody selection: Different TEL2 antibodies may preferentially recognize specific isoforms or epitopes that are differentially accessible.

In Eμ-Myc transgenic mice, TEL2 has been shown to accelerate disease by enlarging the cycling B-cell compartment, thereby increasing chances for p53 mutations. This acceleration is associated with marked up-regulation of Bcl-2, which is normally suppressed in precancerous B cells of Eμ-Myc mice . These biological variations can contribute to inconsistent detection.

What is the optimal protocol for immunoprecipitating TEL2 from primary B-cell samples?

Immunoprecipitation of TEL2 from primary B cells requires careful optimization:

Recommended IP protocol for primary B cells:

• Cell preparation:

  • Isolate primary B cells using magnetic cell separation or flow cytometry

  • Use at least 10-20 million cells per IP reaction

  • Wash cells twice in ice-cold PBS

• Nuclear extraction:

  • Lyse cells in hypotonic buffer (10 mM HEPES pH 7.9, 10 mM KCl, 1.5 mM MgCl2)

  • Add NP-40 to 0.3% and mix gently

  • Pellet nuclei and extract with high-salt buffer (20 mM HEPES pH 7.9, 420 mM NaCl, 1.5 mM MgCl2, 0.2 mM EDTA, 25% glycerol)

• Pre-clearing:

  • Pre-clear lysate with Protein G beads for 1 hour at 4°C

  • Remove beads by centrifugation

• Immunoprecipitation:

  • Add 2-5 μg of TEL2 antibody to pre-cleared lysate

  • Incubate overnight at 4°C with gentle rotation

  • Add Protein G beads and incubate for 2-3 hours

  • Wash 5 times with wash buffer (containing 150 mM NaCl)

• Elution and analysis:

  • Elute with SDS sample buffer at 95°C for 5 minutes

  • Analyze by Western blotting

For capturing TEL2 from primary B cells, agarose-conjugated antibodies can improve efficiency . When investigating TEL2-Myc interactions, consider using a crosslinking agent such as DSP (dithiobis(succinimidyl propionate)) to stabilize transient interactions before cell lysis.

How can I measure changes in TEL2 activity rather than just protein levels?

Measuring TEL2 activity goes beyond protein quantification and requires functional assays:

Reporter gene assay:

• Construct a luciferase reporter with TEL2 binding sites (5′-CCGGAAGT-3′) in the promoter region

• Co-transfect cells with the reporter and TEL2 expression vector

• Measure luciferase activity to quantify TEL2-mediated repression

• Include mutations in the binding site as specificity controls

Chromatin occupancy analysis:

• Perform ChIP-seq using TEL2 antibodies to identify genome-wide binding sites

• Analyze enrichment at known target genes

• Correlate with gene expression data to identify genes regulated by TEL2

Downstream target modulation:

• Monitor expression of known TEL2-regulated genes by qRT-PCR

• Focus on genes involved in cell survival, such as Bcl-2, which is upregulated in TEL2-expressing B cells

• Measure E2f1 and c-Myc expression, which are increased in TEL2-overexpressing B cells

Functional readouts:

• Cell cycle analysis: Measure the percentage of cells in S/G2/M phases

• Apoptosis assays: Quantify apoptotic index using Annexin-V staining

• Proliferation rate: Determine cell doubling time (TEL2-expressing pro-B cells grow approximately three times faster than controls)

How can TEL2 antibodies be used in diagnostic applications for B-cell malignancies?

TEL2 antibodies have potential diagnostic applications in B-cell malignancies based on research findings:

Immunohistochemistry protocol for lymphoma tissue sections:

• Deparaffinize and rehydrate tissue sections

• Perform antigen retrieval (citrate buffer pH 6.0, pressure cooking)

• Block endogenous peroxidase and non-specific binding

• Incubate with primary TEL2 antibody (1:100-1:200 dilution)

• Apply detection system and counterstain

• Evaluate nuclear staining intensity and distribution

Flow cytometry for leukemia classification:

• Prepare single-cell suspensions from blood or bone marrow

• Fix and permeabilize cells for intracellular staining

• Incubate with fluorochrome-conjugated TEL2 antibody

• Co-stain with B-cell markers (CD19, CD20) and MYC antibodies

• Analyze by multiparameter flow cytometry

Research indicates that approximately one-third of B-ALL samples display coordinated elevated expression of MYC/MYCN and TEL2 . The frequency of elevated TEL2 expression in pediatric patient samples (34.8%) is considerably higher than in some cohorts of pediatric ALL (8.7%) . This suggests TEL2 could serve as a diagnostic marker for specific B-cell malignancy subtypes.

What are the best approaches for evaluating TEL2 expression in patient-derived xenograft models?

Patient-derived xenograft (PDX) models provide valuable insights into TEL2's role in human malignancies:

Tissue processing and analysis protocol:

• Harvest PDX tumors and divide for multiple analyses:

  • Fix a portion in formalin for histology

  • Snap-freeze tissue for protein/RNA extraction

  • Process fresh tissue for flow cytometry

• Immunohistochemistry considerations:

  • Use human-specific TEL2 antibodies to distinguish from murine stromal cells

  • Include dual staining with anti-human CD45 to confirm human origin

  • Quantify using digital image analysis for objective assessment

• Molecular analysis:

  • Extract nuclear proteins for Western blotting

  • Perform RT-qPCR to assess TEL2 isoform expression

  • Consider analysis of TEL2 target genes (Bcl-2, E2f1, c-Myc)

• Functional validation:

  • Isolate viable cells from PDX models

  • Transduce with TEL2-targeting shRNAs

  • Assess effects on proliferation and apoptosis in vitro

  • Re-implant manipulated cells to evaluate tumor growth in vivo

When evaluating PDX models, it's important to remember that TEL2's effects on promoting survival may contribute to increased proliferative rates of TEL2-expressing B cells . Additionally, TEL2-expressing pro-B cells have shown the ability to grow indefinitely without undergoing replicative crisis, suggesting TEL2 behaves as an immortalizing oncogene in pro-B cells .

How can I design experiments to investigate the relationship between TEL2 and therapeutic resistance in B-cell malignancies?

Designing experiments to explore TEL2's role in therapeutic resistance requires multifaceted approaches:

In vitro drug resistance models:

• Establish paired sensitive/resistant cell lines

  • Expose B-cell lines to escalating drug concentrations

  • Maintain resistant populations and matched parental controls

• Compare TEL2 expression and activity between sensitive and resistant pairs

• Manipulate TEL2 expression via overexpression or knockdown

• Evaluate changes in drug sensitivity (IC50 values)

Mechanistic investigations:

• Apoptotic pathway analysis:

  • TEL2 suppresses Myc-induced apoptosis

  • Measure key apoptotic regulators (Bcl-2, Bcl-XL, BAX, BAK)

  • Assess mitochondrial membrane potential in TEL2-modified cells

• Cell cycle checkpoint evaluation:

  • TEL2 accelerates cell cycle traverse and increases E2f1 expression

  • Analyze checkpoint proteins (p53, p21, CHK1/2) after drug treatment

  • Determine if TEL2 allows bypass of therapy-induced cell cycle arrest

• Combinatorial approaches:

  • Test TEL2 inhibition in combination with standard therapeutics

  • Evaluate synergistic potential with agents targeting MYC

  • Consider combinations with BCL2 inhibitors, as TEL2 upregulates Bcl-2

Clinical correlation:

• Analyze archived patient samples pre- and post-treatment

• Correlate TEL2 expression with treatment response and outcomes

• Develop TEL2 expression signature that may predict resistance

These approaches can help elucidate whether TEL2's effects on B-cell survival and proliferation contribute to therapeutic resistance, providing potential avenues for targeted intervention.

What novel techniques are being developed to study TEL2 protein-protein interactions and transcriptional complexes?

Emerging technologies are expanding our ability to characterize TEL2's interactome and transcriptional functions:

Proximity-dependent biotinylation (BioID/TurboID):

• Generate TEL2-BioID or TEL2-TurboID fusion constructs

• Express in B-cell models and supply biotin

• Purify biotinylated proteins using streptavidin beads

• Identify proximal proteins by mass spectrometry

CRISPR-based genomic screening:

• Design gRNA libraries targeting potential TEL2 interactors

• Perform screens in TEL2-dependent cellular systems

• Identify synthetic lethal or rescue interactions

• Validate hits with biochemical approaches

Single-cell multi-omics:

• Combine scRNA-seq with scATAC-seq on heterogeneous B-cell populations

• Correlate TEL2 expression with chromatin accessibility patterns

• Identify co-expressed transcription factors

• Map regulatory networks centered on TEL2

Live-cell imaging of transcriptional dynamics:

• Generate fluorescently tagged TEL2 constructs

• Perform FRAP (Fluorescence Recovery After Photobleaching) to measure turnover at chromatin

• Use single-molecule tracking to assess TEL2 binding kinetics

• Implement lattice light-sheet microscopy for improved spatial and temporal resolution

Research has shown that the effects of TEL2 on B-cell growth required its protein-protein interaction and transcription functions, as demonstrated by experiments with TEL2ΔPNT (which lacks the pointed protein-protein interaction domain) and TEL2-DBDM constructs . These emerging techniques can help further characterize these functional domains and their interacting partners.

How can CRISPR-Cas9 technology be leveraged to study TEL2 function in combination with TEL2 antibodies?

CRISPR-Cas9 technology offers powerful approaches to investigate TEL2 function:

Genome editing strategies:

• Knockout validation:

  • Generate TEL2 knockout cell lines

  • Confirm deletion using TEL2 antibodies

  • Use as negative controls for antibody validation

• Endogenous tagging:

  • Insert epitope tags (FLAG, HA) at the TEL2 locus

  • Compare detection with endogenous TEL2 antibodies

  • Perform tandem purification with both tag and TEL2 antibodies

• Domain mutagenesis:

  • Introduce point mutations in functional domains (e.g., DNA binding domain)

  • Assess alterations in protein-protein interactions

  • Evaluate effects on transcriptional repression

Functional genomics applications:

• CRISPRi/CRISPRa:

  • Modulate TEL2 expression without altering the coding sequence

  • Compare protein modulation detection by antibodies

  • Assess downstream effects on target genes

• CRISPR screens:

  • Screen for genes that modify TEL2-dependent phenotypes

  • Use TEL2 antibodies to confirm expression in screen populations

  • Validate hits with individual knockouts

• CRISPR base editing:

  • Introduce specific mutations in TEL2 binding sites

  • Evaluate effects on TEL2 recruitment using ChIP with TEL2 antibodies

  • Assess changes in target gene expression

These approaches can help elucidate the molecular mechanisms behind TEL2's ability to promote B-cell survival and proliferation, as well as its cooperation with Myc in B-cell lymphomas .

What are the current hypotheses regarding TEL2 isoform-specific functions and how can researchers investigate them?

The existence of multiple TEL2 isoforms raises important questions about their specific functions:

Current hypotheses on isoform-specific roles:

• Differential DNA binding: Isoforms may recognize distinct DNA elements or exhibit varied binding affinities

• Altered protein interactions: Different isoforms may recruit distinct co-repressor complexes

• Subcellular localization: Some isoforms may localize to specific nuclear domains

• Cell-type specificity: Isoform expression patterns may vary across hematopoietic lineages

• Dominant-negative effects: Shorter isoforms may antagonize full-length TEL2 function

Experimental approaches to investigate isoform functions:

• Expression profiling:

  • Design isoform-specific qPCR primers spanning unique exon junctions

  • Analyze expression patterns across normal and malignant B-cell populations

  • Correlate with disease subtypes and patient outcomes

• Isoform-specific antibodies:

  • Generate antibodies targeting unique epitopes in specific isoforms

  • Validate specificity using isoform-specific knockdowns

  • Apply in Western blotting, ChIP, and immunofluorescence

• Functional comparison:

  • Express individual isoforms in TEL2-null backgrounds

  • Compare effects on proliferation, apoptosis, and immortalization

  • Perform RNA-seq to identify isoform-specific target genes

• Proteomic analysis:

  • Immunoprecipitate each isoform separately

  • Identify differential binding partners by mass spectrometry

  • Map interaction domains through deletion mutagenesis

Alternative splicing of TEL2 results in seven isoforms (designated A-G) , which may have distinct regulatory functions and implications in various biological processes. Understanding these isoform-specific functions could provide insights into TEL2's role in normal B-cell development and malignant transformation.