The FITC-conjugated ETV7 antibody is utilized in diverse experimental workflows:
Detects ETV7 protein expression in lysates.
Example Protocol:
Visualizes ETV7 localization in fixed cells, particularly in nuclear compartments .
Key Use Case: Studying ETV7’s role in repressing ISGs in antiviral pathways (e.g., influenza virus models) .
Species: Tested in human, dog, and horse (Aviva Systems Biology) .
Validation: ChIP-qPCR and pull-down assays confirm ETV7 binding to ISG promoters containing ETS motifs (e.g., ISG15, IFI44L) .
ETV7’s FITC-conjugated antibody has been instrumental in elucidating its role in:
Mechanism: ETV7 binds to ISRE motifs within ISG promoters (e.g., ISG15, IFI44L) and represses transcription .
Impact: Loss of ETV7 enhances ISG expression (e.g., IFITM1, OAS1) and improves antiviral defense against influenza viruses .
Role: Overexpression of ETV7 in breast cancer cells reduces sensitivity to chemotherapy and radiotherapy by repressing IFN-responsive genes .
ETV7 (also known as TEL2, TELB, or TREF) is a transcriptional repressor belonging to the ETS family of transcription factors. It binds to the DNA sequence 5'-CCGGAAGT-3' and functions as a negative regulator of gene expression . Recent research has demonstrated that ETV7 plays significant roles in:
Limiting antiviral gene expression by suppressing interferon-stimulated genes (ISGs), which affects viral control particularly in influenza infection models
Promoting cancer progression, as evidenced in colorectal cancer where it upregulates IFIT3 expression
Regulating breast cancer stem-like cell plasticity and contributing to resistance against chemotherapy and radiotherapy
Unlike most ETS transcription factors that act as activators, ETV7 primarily functions as a repressor of gene expression, particularly of interferon-responsive genes . The protein exhibits isoform-specific activity, with isoforms A and C reportedly lacking repressor activity .
ETV7 primarily functions as a nuclear transcription factor that binds to specific DNA sequences within promoter regions. When designing immunofluorescence experiments with FITC-conjugated ETV7 antibodies, researchers should:
Implement appropriate nuclear permeabilization steps during sample preparation
Optimize fixation protocols that preserve nuclear architecture while allowing antibody access
Consider counterstaining with nuclear dyes (e.g., DAPI) to confirm nuclear localization
Be aware that certain cell types or conditions may result in cytoplasmic localization of inactive ETV7
The expected nuclear staining pattern should show punctate or diffuse nuclear signals corresponding to ETV7's binding to DNA regions containing its target sequence . Unexpected cytoplasmic staining may indicate either non-specific binding or biologically relevant relocalization under certain conditions.
When selecting an ETV7 antibody for flow cytometry applications:
Epitope specificity: Choose antibodies targeting conserved regions to detect all ETV7 isoforms, or isoform-specific epitopes if studying particular variants.
Validation status: Prioritize antibodies validated specifically for flow cytometry applications with human samples, as seen with some commercial options .
Clone type: Consider whether polyclonal (broader epitope recognition) or monoclonal (higher specificity) antibodies are more appropriate for your research question.
Fluorophore properties: For FITC conjugation specifically, ensure the excitation/emission profile (494/518 nm) is compatible with your flow cytometer configuration and other fluorophores in your panel.
Fixation compatibility: Verify the antibody performs well with your preferred fixation protocol, as some epitopes may be sensitive to particular fixatives.
Preliminary titration experiments are essential to determine optimal antibody concentration that maximizes signal-to-noise ratio for your specific cell type and experimental conditions .
For optimal detection of ETV7 using FITC-conjugated antibodies, consider these methodological approaches:
For Flow Cytometry:
Harvest cells in log-phase growth to ensure consistent ETV7 expression
Fix cells with 2-4% paraformaldehyde for 10-15 minutes at room temperature
Permeabilize with 0.1-0.3% Triton X-100 or commercially available permeabilization buffers
Block with 5% normal serum (matching secondary antibody host species if using indirect methods)
Stain with pre-titrated FITC-conjugated ETV7 antibody (typically 0.5-5 μg/ml)
Include unstained, isotype, and positive controls in each experiment
For Immunofluorescence:
Culture cells on appropriate coverslips or chamber slides
Fix with 4% paraformaldehyde for 15 minutes (or methanol for 10 minutes at -20°C)
Permeabilize with 0.2% Triton X-100 for 10 minutes
Block with 5% BSA in PBS for 1 hour
Incubate with FITC-conjugated ETV7 antibody at 4°C overnight or 2 hours at room temperature
Counterstain nucleus with DAPI and mount with anti-fade mounting medium
The choice between these protocols should depend on your specific research question and cell type, with particular attention to preserving the nuclear localization of ETV7.
To study ETV7's role in interferon responses using FITC-conjugated antibodies:
Stimulation design: Treat cells with various concentrations of type I interferons (e.g., IFN-α2, IFN-β) for different time periods (2-24 hours) to capture the dynamic regulation of ETV7.
Co-staining approach: Implement multi-color flow cytometry with FITC-conjugated ETV7 antibodies alongside APC or PE-conjugated antibodies against key ISGs such as IFIT1, IFIT2, or ISG15, which are known to be regulated by ETV7 .
Kinetic analysis: Analyze ETV7 expression at various timepoints following interferon stimulation to establish:
Baseline expression
Peak induction timepoint
Correlation with suppression of other ISGs
Comparative cell analysis: Include both:
Genetic manipulation: Combine antibody staining with ETV7 knockout or overexpression systems to directly assess its regulatory impact on the interferon response .
This methodological approach allows for quantitative assessment of how ETV7 expression correlates with the suppression of other ISGs following interferon stimulation, providing insights into its function as a negative regulator of antiviral responses .
When using FITC-conjugated ETV7 antibodies, implement these essential controls:
Technical Controls:
Unstained cells: To establish autofluorescence baseline and set negative population gates
FITC-conjugated isotype control: Matched to ETV7 antibody's host species and isotype to identify non-specific binding
Single-stained controls: If performing multicolor experiments, for compensation calculation
FMO (Fluorescence Minus One): Includes all fluorophores except FITC to establish appropriate positive gating strategy
Biological Controls:
Positive control: Cell lines with confirmed ETV7 expression (e.g., IFN-stimulated A549 cells)
Negative control: Either:
Induction control: Paired samples with and without interferon treatment to confirm antibody can detect the expected upregulation of ETV7
siRNA treated cells: Cells treated with siRNA targeting ETV7 to confirm specificity of antibody binding
These controls are critical for distinguishing true ETV7 signal from background, especially given that ETV7 expression is often induced rather than constitutive, making appropriate positive and negative controls particularly important for accurate interpretation .
Optimizing multicolor panels containing FITC-conjugated ETV7 antibodies requires careful consideration of several technical factors:
Spectral Properties and Panel Design:
FITC excites at 494nm and emits at 518nm, placing it in the green spectrum
Avoid fluorophores with significant spectral overlap such as PE (575nm), GFP, or CFSE
Assign FITC to targets with expected intermediate-to-high expression levels as FITC has moderate brightness
Reserve brighter fluorophores (APC, PE-Cy7) for lower-expressed targets
Compensation Strategy:
Prepare single-color controls using the same cell type and antibody concentrations as the full panel
Include a FITC single-stained control using the ETV7 antibody rather than generic FITC beads when possible
Perform compensation matrix calculation before each experiment, especially if instrument settings change
Consider manual adjustment of FITC spillover into PE channels if automated compensation is insufficient
Panel Validation:
Test antibodies individually before combining into a full panel
Compare Mean Fluorescence Intensity (MFI) of ETV7-FITC alone versus in the full panel to detect potential interactions
Verify that the pattern of ETV7 expression (e.g., interferon-inducible) is maintained in the multicolor context
Conduct FMO controls to establish proper gating strategies for each marker
This systematic approach ensures that FITC-conjugated ETV7 antibody performance is not compromised within complex multicolor panels while maintaining detection sensitivity for biologically relevant expression changes.
When encountering weak or inconsistent signals with FITC-conjugated ETV7 antibodies, consider these troubleshooting approaches:
Sample Preparation Issues:
Insufficient permeabilization: Increase concentration or duration of permeabilization agent for better nuclear access
Overfixation: Reduce fixation time or concentration to preserve epitope accessibility
Inadequate blocking: Increase blocking duration or concentration to reduce background
Antibody-Specific Factors:
Titration optimization: Perform a detailed titration series (e.g., 0.1-10 μg/ml) to identify optimal concentration
Incubation conditions: Test longer incubation periods (overnight at 4°C vs. 1-2 hours at room temperature)
Lot-to-lot variation: Compare performance across different antibody lots if available
Signal Enhancement Strategies:
Secondary amplification: Consider using unconjugated primary anti-ETV7 followed by FITC-conjugated secondary antibody
Biotin-streptavidin systems: Implement multi-step detection with biotinylated primary and streptavidin-FITC
Signal enhancers: Evaluate commercial fluorescence enhancer solutions compatible with FITC
Biological Considerations:
Induction status: Verify ETV7 expression through qPCR as protein levels may be low without interferon stimulation
Cell type variability: Compare ETV7 detection across multiple cell lines as baseline expression varies significantly
Expression kinetics: Test different timepoints post-stimulation as ETV7 expression is dynamically regulated
Document all optimization steps systematically to establish a reproducible protocol for your specific experimental system .
FITC is particularly susceptible to photobleaching, which can significantly impact experiments using FITC-conjugated ETV7 antibodies:
Impacts on Experimental Outcomes:
Progressive signal loss during extended imaging sessions
Reduced sensitivity for detecting low-expression ETV7 populations
Inconsistent quantification between early and late-acquired samples
False negatives in cells with borderline ETV7 expression levels
Mitigation Strategies:
Sample Preparation:
Use anti-fade mounting media containing radical scavengers
Store slides in the dark at 4°C until imaging
Prepare fresh samples for each major experiment rather than reusing
Instrument Settings:
Reduce excitation intensity to minimum required for adequate signal detection
Optimize gain/PMT voltage rather than increasing laser power
Use shortest exposure time that provides acceptable signal-to-noise ratio
Consider using confocal rather than widefield microscopy for more precise excitation
Acquisition Protocol:
Image FITC channels first in multicolor experiments
Minimize focus time using brightfield or DAPI channels before capturing FITC images
Use binning to reduce required exposure time
Implement image acquisition software with anti-bleaching modules
Alternative Approaches:
Consider more photostable green fluorophores (Alexa Fluor 488, BODIPY)
Use software with photobleaching correction algorithms for quantitative analysis
Implement spectral unmixing if using multiple green-yellow fluorophores
By implementing these strategies, researchers can maintain signal integrity throughout their experiments and ensure more consistent and reliable detection of ETV7 expression patterns .
FITC-conjugated ETV7 antibodies offer powerful tools for investigating ETV7's role in viral infections through several advanced methodological approaches:
Single-Cell Co-Expression Analysis:
Implement multiparameter flow cytometry using FITC-conjugated ETV7 antibodies alongside viral markers and key ISGs (IFIT1, IFIT2, ISG15)
Quantify correlation between ETV7 expression levels and viral load at the single-cell level
Compare ETV7 expression in infected versus bystander cells within the same culture
Temporal Dynamics of ETV7 Regulation:
Perform time-course experiments following viral infection (e.g., influenza virus)
Analyze the kinetics of ETV7 upregulation relative to other ISGs
Correlate ETV7 expression timing with subsequent suppression of antiviral ISGs
Infection Susceptibility Correlation:
Sort cells based on ETV7-FITC signal intensity prior to viral challenge
Determine whether ETV7-high versus ETV7-low populations show differential susceptibility
Combine with viral reporter systems (e.g., PR8-mNeon) to directly measure infection efficiency
Therapeutic Intervention Models:
Use FITC-conjugated ETV7 antibodies to monitor changes in ETV7 expression during IFN-α2 treatment
Correlate ETV7 levels with therapeutic responsiveness to interferon therapy
Investigate ETV7 as a biomarker for predicting antiviral treatment efficacy
These approaches leverage the ability to quantitatively assess ETV7 expression at the single-cell level, facilitating investigation into its role as a negative regulator of the interferon response that influences viral control, particularly for influenza viruses .
Researchers can implement several sophisticated strategies to investigate ETV7's role in cancer using FITC-conjugated antibodies:
Cancer Stem Cell Identification:
Combine ETV7-FITC with established cancer stem cell markers (CD44+/CD24low for breast cancer)
Perform multiparameter flow cytometry to identify ETV7 expression patterns within stem-like populations
Sort ETV7-high versus ETV7-low cancer stem cells for functional assays (mammosphere formation, tumor initiation)
Therapy Resistance Correlation:
Monitor ETV7 expression changes before, during, and after chemotherapy or radiotherapy
Compare ETV7 levels between therapy-resistant and sensitive cell populations
Analyze whether ETV7 expression predicts treatment response in patient-derived samples
Signaling Pathway Analysis:
Use phospho-flow cytometry combining ETV7-FITC with antibodies against phosphorylated signaling proteins
Investigate how ETV7 expression correlates with activation of specific oncogenic pathways
Implement inhibitor studies to determine pathways regulating ETV7 expression
Target Gene Regulation:
Perform ETV7/IFIT3 co-expression analysis using multicolor flow cytometry
Sort ETV7-expressing cells to analyze expression of putative target genes
Correlate ETV7 levels with cellular phenotypes (proliferation, migration, colony formation)
Tumor Microenvironment Interactions:
Analyze ETV7 expression in tumor cells versus infiltrating immune cells
Investigate how interferon signaling from immune cells affects ETV7 expression in tumor cells
Determine whether ETV7 mediates escape from immune surveillance through ISG regulation
These approaches leverage the quantitative and single-cell resolution capabilities of flow cytometry with FITC-conjugated ETV7 antibodies to dissect complex roles in cancer progression and therapy resistance .
Researchers can develop sophisticated approaches to quantitatively assess ETV7's transcriptional repressor function using antibody-based methods:
Chromatin Immunoprecipitation (ChIP) Combined with Flow Cytometry:
Use FITC-conjugated ETV7 antibodies to sort cells based on ETV7 expression levels
Perform ChIP on sorted populations to analyze ETV7 binding to specific promoters
Compare occupancy of ETV7 at target sites like ISG15 or IFI44L promoters across different expression levels
Quantify correlation between ETV7 binding and target gene repression
Protein Interaction Analysis:
Implement Proximity Ligation Assay (PLA) with ETV7 antibodies and antibodies against potential co-repressors
Quantify ETV7-IRF interactions that may mediate target selection at ETS-IRF composite elements (EICEs)
Analyze how protein interaction networks differ in interferon-stimulated versus unstimulated conditions
Single-Cell Transcriptional Repression Quantification:
Combine ETV7-FITC staining with RNA-FISH for target genes
Analyze the inverse correlation between ETV7 protein levels and target RNA abundance
Implement index sorting to link single-cell transcriptomes with ETV7 protein levels
Reporter System Analysis:
Use cells containing ISRE-reporter constructs like the A549-IFN response cells
Quantify ETV7-mediated suppression of reporter activity using flow cytometry
Correlate ETV7 expression with repression efficiency across heterogeneous populations
Dynamic Repression Analysis:
Implement live-cell imaging with destabilized reporters under ETV7-repressible promoters
Correlate temporal changes in ETV7 levels with dynamic repression of target genes
Analyze kinetics of repression and de-repression during interferon stimulation and withdrawal
These methods provide quantitative insights into ETV7's repressive function, particularly its role in suppressing ISGs containing ETS binding sites within ISRE sequences, advancing understanding of how this transcription factor regulates interferon responses .
When encountering heterogeneous ETV7 expression patterns, researchers should implement these analytical approaches:
Biological Interpretation Frameworks:
Cell Cycle Dependency Analysis:
Combine ETV7-FITC with DNA content staining (e.g., DAPI, propidium iodide)
Determine whether ETV7 expression correlates with specific cell cycle phases
Compare cycling versus quiescent populations for differential ETV7 expression patterns
Differentiation State Assessment:
Signaling Pathway Activation Status:
Quantitative Analysis Approaches:
Population Density Mapping:
Use bivariate analysis plotting ETV7-FITC against relevant markers
Implement dimensionality reduction techniques (tSNE, UMAP) for multiparameter data
Apply clustering algorithms to identify discrete subpopulations based on expression profiles
Threshold Determination:
This comprehensive approach recognizes that heterogeneous ETV7 expression likely reflects important biological variability rather than technical artifacts, potentially revealing distinct functional states relevant to both cancer progression and antiviral responses .
When analyzing flow cytometry data from FITC-conjugated ETV7 antibody experiments, researchers should consider these statistical approaches:
Descriptive Statistics:
Median Fluorescence Intensity (MFI): Preferred over mean for non-normally distributed flow data
Coefficient of Variation (CV): To quantify population heterogeneity in ETV7 expression
Frequency of positive cells: Using properly established thresholds based on controls
Bimodality coefficient: To quantify whether ETV7 expression follows unimodal or bimodal distribution
Comparative Statistical Tests:
Non-parametric tests: Mann-Whitney U or Kruskal-Wallis for comparing ETV7 expression between conditions
Paired tests: Wilcoxon signed-rank test for comparing matched samples (e.g., before/after treatment)
ANOVA with post-hoc tests: For comparing multiple experimental conditions with normal distribution
Multiple testing correction: Bonferroni or False Discovery Rate correction when comparing across multiple parameters
Advanced Analytical Methods:
Correlation analysis: Spearman rank correlation to assess relationships between ETV7 and ISGs or cancer markers
Regression modeling: To determine factors predicting ETV7 expression levels
Multivariate analysis: Principal Component Analysis or t-SNE to identify patterns in high-dimensional data
Mixture modeling: To objectively identify subpopulations within heterogeneous samples
Specific Considerations for ETV7 Data:
Account for interferon-induced upregulation when comparing across treatment conditions
Implement paired analysis when comparing effects of ETV7 knockdown or overexpression
Consider time as a covariate when analyzing dynamic changes in ETV7 expression
Normalize ETV7 expression to housekeeping proteins when comparing across cell types
These statistical approaches ensure robust and reliable interpretation of ETV7 expression data, particularly important when studying the dynamic and context-dependent expression patterns of this transcription factor .
Integrating ETV7 antibody-based protein data with transcriptomic findings requires sophisticated analytical approaches to illuminate ETV7's repressive mechanisms:
Integrated Data Collection Strategies:
Sequential Analysis Approach:
Parallel Profiling Methods:
Implement CITE-seq or similar technologies to simultaneously capture surface proteins and transcriptomes
Correlate ETV7 protein levels with RNA expression profiles at single-cell resolution
Identify genes showing inverse correlation with ETV7 protein abundance
Analytical Integration Frameworks:
Promoter Motif Analysis:
Network Analysis:
Comparative Pathway Analysis:
Validation Approaches:
Integrated ChIP-seq and RNA-seq:
This integrated approach provides mechanistic insights into how ETV7 selectively represses specific interferon-stimulated genes, particularly those with ETS binding sites within their promoters, contributing to understanding its role in both antiviral responses and cancer progression .
Several cutting-edge technologies could significantly advance ETV7 research beyond traditional antibody-based methods:
Genome Editing and Protein Tagging:
CRISPR knock-in approaches: Endogenous tagging of ETV7 with fluorescent proteins or epitope tags
Split fluorescent protein systems: For studying ETV7 protein interactions without antibodies
Degradation tag systems: Such as auxin-inducible degrons for temporal control of ETV7 levels
Advanced Imaging Technologies:
Super-resolution microscopy: Techniques like STORM or PALM to visualize ETV7 localization at sub-diffraction resolution
Lattice light-sheet microscopy: For dynamic imaging of ETV7 within living cells
FRET-based biosensors: To detect ETV7 interactions with DNA or protein partners in real-time
Single-Cell Multi-Omics:
CITE-seq/REAP-seq: To correlate ETV7 protein levels with transcriptome at single-cell resolution
CUT&Tag or CUT&RUN: For profiling ETV7 genomic binding sites with higher sensitivity than ChIP
Spatial transcriptomics: To analyze ETV7 expression and activity in tissue context
Protein-Centered Technologies:
Mass cytometry (CyTOF): For high-parameter analysis of ETV7 in relation to cellular signaling networks
Proximity-dependent biotinylation: BioID or TurboID approaches to map ETV7 protein interaction networks
Cross-linking mass spectrometry: To identify direct protein-protein interactions involving ETV7
Functional Genomics Integration:
CRISPR screens with ETV7 reporters: To identify regulators of ETV7 expression or activity
Perturb-seq approaches: Combining CRISPR perturbations with single-cell RNA-seq to identify ETV7-dependent gene networks
DNA-protein interaction mapping: Using techniques like SELEX-seq to define ETV7 binding preferences beyond known motifs
These emerging technologies promise to reveal deeper insights into ETV7's dynamic regulation, molecular interactions, and context-specific functions in both antiviral responses and cancer progression .
Research on ETV7 has revealed several promising therapeutic applications that merit further investigation:
Viral Infection Applications:
ETV7 inhibition strategies: Development of small molecules or peptides that target ETV7's repressive function to enhance antiviral responses
Combination with IFN therapy: Pairing ETV7 inhibition with interferon treatment for enhanced viral clearance
Biomarker development: Using ETV7 expression as a predictive biomarker for interferon therapy response
Targeted approaches for influenza: Particularly promising given ETV7's demonstrated role in influenza virus control
Cancer Therapeutic Applications:
Targeting cancer stem cell populations: Developing approaches to modulate ETV7 in cancer stem-like cells to reduce therapy resistance
Combination with chemotherapy: ETV7 inhibition may enhance effectiveness of existing treatments by reducing therapy resistance
Pathway-specific interventions: Targeting the ETV7-IFIT3 axis in colorectal cancer to suppress tumor progression
Immunotherapy enhancement: Modulating ETV7 to prevent suppression of interferon responses within the tumor microenvironment
Methodological Requirements for Translation:
Development of highly specific ETV7 inhibitors that don't affect other ETS family members
Further characterization of tissue-specific effects and potential off-target impacts
Biomarker development to identify patients most likely to benefit from ETV7-targeted approaches
Careful consideration of potential consequences of disrupting ETV7's role in preventing excessive inflammation
Research suggests particular promise for ETV7-targeted approaches in two key areas: enhancing control of influenza and other viral infections through potentiation of interferon responses, and overcoming therapy resistance in cancers where ETV7 promotes stem-like cell characteristics .
Single-cell approaches using FITC-conjugated ETV7 antibodies offer transformative potential for understanding cellular heterogeneity:
Mapping Response Heterogeneity in Viral Infection:
Identify discrete cell subpopulations with differential ETV7 induction following interferon stimulation
Correlate single-cell ETV7 expression with viral susceptibility at individual cell level
Discover potentially rare "super-responder" or "non-responder" cells with extreme ETV7 phenotypes
Characterize whether heterogeneity represents stochastic variation or distinct cellular states
Cancer Cellular Hierarchy Delineation:
Combine ETV7-FITC with stem cell markers to precisely map cellular hierarchies in tumors
Identify transitional states between differentiated and stem-like phenotypes
Correlate ETV7 expression with functions like self-renewal, differentiation, and therapy resistance
Discover rare tumor-initiating cells with distinctive ETV7 expression patterns
Dynamic Cell State Transitions:
Implement index sorting to link ETV7 protein levels with single-cell transcriptomes
Track temporal changes in ETV7 expression during differentiation or treatment response
Identify early molecular changes preceding phenotypic transitions
Apply trajectory inference methods to map developmental paths between cellular states
Spatial Context Integration:
Combine flow cytometry with spatial techniques like imaging mass cytometry
Map ETV7 expression patterns relative to microenvironmental niches
Identify spatial gradients in ETV7 expression correlating with external stimuli
Analyze cell-cell communication networks influencing ETV7 regulation
Technical Innovations Required:
Higher sensitivity detection methods for low-abundance transcription factors
Integration with protein modification analysis (phosphorylation, SUMOylation)
Computational approaches for integrating protein and transcriptomic data
Live-cell tracking of ETV7 dynamics during cellular transitions
These single-cell approaches would transform our understanding of how heterogeneous ETV7 expression contributes to diverse cellular responses in both viral infection and cancer contexts, potentially revealing new therapeutic opportunities targeting specific cellular subpopulations .