Nr2f6 Antibody

What is NR2F6 and why is it important in immunology research?

NR2F6 (Nuclear Receptor Subfamily 2 Group F Member 6) is an orphan nuclear receptor that functions as a transcription factor by binding to TGACCT direct-repeat motifs. Its importance in immunology stems from its role as a negative regulator of T cell activation responses. NR2F6 acts as a nuclear attenuator that directly interferes with the DNA binding of NF-AT (Nuclear Factor of Activated T cells) and subsequently inhibits the transcriptional activity of NF-AT-dependent cytokine promoters, particularly IL-17A . Mechanistically, research has demonstrated that NR2F6 potently antagonizes the ability of T helper 0 (Th0) and Th17 CD4+ T cells to induce expression of key cytokine genes such as interleukin-2 (IL-2) and IL-17 . This functionality positions NR2F6 as a crucial checkpoint in immune responses, with particular relevance to autoimmune conditions and cancer immunotherapy research.

What experimental applications are NR2F6 antibodies typically used for?

NR2F6 antibodies are employed across multiple experimental techniques in molecular and cellular biology:

When selecting an NR2F6 antibody, researchers should verify reactivity with their species of interest (commonly human, mouse, or rat) and validate antibody specificity using appropriate controls such as NR2F6 knockout samples where possible .

How should researchers optimize IHC protocols for optimal NR2F6 detection in tissue samples?

For optimal detection of NR2F6 in tissue samples via immunohistochemistry:

• Fixation considerations: Use 10% neutral buffered formalin fixation for 24-48 hours, as overfixation can mask the NR2F6 epitope.

• Antigen retrieval optimization:

  • Primary recommendation: Heat-induced epitope retrieval with TE buffer at pH 9.0

  • Alternative method: Citrate buffer at pH 6.0 if TE buffer yields high background

• Blocking protocol: Implement a dual blocking approach:

  • 3% hydrogen peroxide (10 minutes) to quench endogenous peroxidases

  • 5% normal serum from the same species as the secondary antibody (1 hour)

• Antibody incubation parameters:

  • Initial titration experiments should test dilutions from 1:50 to 1:500

  • Incubate primary antibody at 4°C overnight for maximal sensitivity

  • Use validated positive controls (human ovary tumor tissue or kidney tissue have shown consistent positivity)

• Signal amplification: For low-expressing samples, employ tyramide signal amplification systems that can enhance sensitivity without increasing background.

Finally, validation using siRNA or CRISPR-engineered NR2F6 knockdown samples provides the most rigorous confirmation of antibody specificity in IHC applications.

What are the critical considerations for validating NR2F6 antibody specificity in research applications?

Thorough validation of NR2F6 antibody specificity requires a multi-faceted approach:

• Genetic validation: The gold standard for antibody validation is testing in NR2F6 knockout or knockdown models:

  • Verify complete absence of signal in NR2F6 knockout samples

  • Demonstrate proportional signal reduction in shRNA-mediated knockdown samples

• Technical validation across applications:

  • Western blot should show a single band at approximately 43 kDa (the calculated molecular weight of NR2F6)

  • IHC patterns should match known tissue expression profiles

  • Compare results from multiple antibodies targeting different NR2F6 epitopes

• Specificity controls:

  • Pre-adsorption with the immunizing peptide should eliminate specific signal

  • Omission of primary antibody should result in no signal

  • Isotype control antibodies should not show specific staining

• Recombinant expression validation:

  • Overexpression of tagged NR2F6 constructs should result in increased signal intensity

  • Co-localization of antibody signal with tag-specific antibodies confirms target recognition

Researchers should document these validation steps thoroughly in publications to enhance experimental reproducibility in the NR2F6 research field.

How does NR2F6 expression correlate with cancer prognosis and immunotherapy response?

Multiple studies have identified significant associations between NR2F6 expression and cancer outcomes:

• Melanoma:

  • Higher NR2F6 expression correlates with less favorable prognosis

  • NR2F6 expression patterns coincide inversely with IFNγ signature, which is associated with positive responses to immunotherapy

  • Patients with lower NR2F6 expression show better responses to immune checkpoint therapy (ICT)

• Non-small cell lung cancer (NSCLC):

  • NR2F6 is highly expressed in NSCLC tissues compared to normal lung tissue

  • High expression positively correlates with depth of invasion, lymphatic metastasis, and advanced clinical stage

  • Kaplan-Meier analysis demonstrated that high NR2F6 expression is significantly associated with poor prognosis in NSCLC patients

• Glioma:

  • NR2F6 expression significantly correlates with tumor aggressiveness

  • Functions as a potential immunosuppression-mediator in the glioma microenvironment

  • Associated with multiple immune-related functions including recruitment of immunosuppressive cells and secretion of immunosuppressive cytokines

These findings suggest NR2F6 expression analysis using validated antibodies may serve as a valuable biomarker for patient stratification in immunotherapy trials across multiple cancer types.

What mechanisms underlie NR2F6's role in tumor immune evasion, and how can researchers investigate them?

Research indicates NR2F6 facilitates tumor immune evasion through multiple mechanisms that can be experimentally investigated:

• Regulation of tumor microenvironment:

  • NR2F6 influences CD8+ T cell infiltration and function in the tumor microenvironment

  • Experimental approach: Compare CD8+ T cell infiltration in NR2F6-deficient versus wild-type tumors using immunofluorescence and flow cytometry

  • Research finding: NR2F6 loss in B16F10 and YUMM1.7 melanoma cells attenuated tumor development via increased CD8+ T cell infiltration

• Impact on immune checkpoint pathways:

  • NR2F6 can function synergistically with other immune checkpoints

  • Experimental approach: Test combination of NR2F6 inhibition with anti-PD1 therapy in mouse models

  • Research finding: Further delay of melanoma development was achieved upon combination of NR2F6 inhibition with anti-PD1 therapy

• Transcriptional regulation of immune response genes:

  • NR2F6 controls expression of genes functioning to suppress anti-tumor immunity

  • Experimental approach: RNA-seq analysis comparing NR2F6 knockdown versus control tumor cells

  • Research finding: NR2F6 depletion altered expression patterns of immune-related genes

• Host-tumor interaction studies:

  • NR2F6 function involves both tumor-intrinsic and tumor-extrinsic mechanisms

  • Experimental approach: Compare tumor growth in:

    • Wild-type mice with NR2F6-deficient tumors

    • NR2F6 knockout mice with wild-type tumors

    • NR2F6 knockout mice with NR2F6-deficient tumors

  • Research finding: NR2F6 depletion both in tumors and systemically promoted a further decrease in melanoma growth by 86.37-91.69% compared to individual depletion effects

Researchers can use NR2F6 antibodies in these experimental contexts to track protein expression, localization, and interactions in both tumor and immune cells.

How can ChIP-seq with NR2F6 antibodies reveal genome-wide binding patterns and transcriptional networks?

Chromatin immunoprecipitation followed by sequencing (ChIP-seq) using NR2F6 antibodies provides valuable insights into its genome-wide binding patterns and transcriptional regulatory networks:

• Antibody selection for ChIP-seq:

  • Critical considerations: High specificity and affinity for the native (non-denatured) NR2F6 protein

  • Validation approach: Test multiple antibodies in preliminary ChIP-qPCR experiments targeting known NR2F6 binding sites

  • Technical note: For NR2F6, antibodies recognizing the DNA-binding domain may be less effective due to epitope masking when bound to chromatin

• ChIP-seq experimental design:

  • Cross-linking conditions: 1% formaldehyde for 10 minutes optimizes NR2F6 capture

  • Sonication parameters: Aim for 200-300bp fragments for optimal resolution of binding sites

  • Input controls and negative controls (IgG or NR2F6-depleted samples) are essential

  • Consider dual cross-linking with DSG (disuccinimidyl glutarate) before formaldehyde to improve capture of indirect DNA interactions

• Data analysis and interpretation:

  • Motif analysis: Focus on TGACCT direct-repeat motifs, the known binding sequence for NR2F6

  • Look for co-occurring transcription factor binding sites, particularly NF-AT binding motifs

  • Integrate with RNA-seq data from NR2F6 knockdown experiments to identify direct regulatory targets

  • For immune contexts, analyze binding at cytokine gene loci (IL-2, IL-17) where NR2F6 has known regulatory functions

• Validating ChIP-seq findings:

  • Confirm key binding sites with ChIP-qPCR using independent antibodies

  • Perform EMSA (Electrophoretic Mobility Shift Assay) with the core binding sequence (5′-GTGTCAAAGGTCGTGTCAAAGGTC-3′)

  • Use reporter gene assays to validate functional significance of binding sites

This approach has successfully identified NR2F6 binding to regulatory regions of genes involved in immune responses and can be extended to study its role in cancer and other biological contexts.

What are the best approaches for studying NR2F6 protein-protein interactions in different cellular contexts?

Understanding NR2F6 protein-protein interactions requires multiple complementary approaches:

• Co-immunoprecipitation (Co-IP):

  • Forward approach: Immunoprecipitate with NR2F6 antibody, detect interaction partners by Western blot

  • Reverse approach: Immunoprecipitate suspected interaction partners, detect NR2F6

  • Research finding: Co-IP experiments verified NR2F6 interaction with HNRNPD in lung cancer cells

  • Technical consideration: Use gentle lysis buffers (150mM NaCl, 0.5% NP-40) to preserve interactions

• Proximity ligation assay (PLA):

  • Advantages: Visualizes protein interactions in situ with subcellular localization

  • Application: Particularly valuable for studying context-dependent interactions in heterogeneous tissue samples

  • Requires: Pair of primary antibodies raised in different species (e.g., mouse anti-NR2F6 and rabbit anti-interactor)

• Chromatin-focused interaction studies:

  • ChIP-reChIP: Sequential immunoprecipitation with NR2F6 antibody followed by antibodies against suspected co-regulators

  • Example application: Study interaction between NR2F6 and NF-AT on chromatin at IL-17 promoter regions

  • Research precedent: NR2F6 directly interferes with DNA binding of NF-AT, affecting transcriptional activity

• Mass spectrometry-based approaches:

  • Immunoprecipitate NR2F6 from different cellular contexts (e.g., resting vs. activated T cells)

  • Perform liquid chromatography-tandem mass spectrometry (LC-MS/MS)

  • Cross-reference with known interactors of nuclear receptors

  • Cross-validate top hits with targeted Co-IP experiments

• Advanced methodologies for dynamic interactions:

  • Low-Dose Ionizing Radiation-Crosslinking Immunoprecipitation (LDIR-CLIP) has been used to study RNA-binding protein interactions involving NR2F6

  • FRET (Fluorescence Resonance Energy Transfer) with fluorescently tagged proteins can reveal direct interactions in living cells

These approaches collectively provide a comprehensive view of NR2F6's interaction network across different cellular states and contexts.

How can researchers address non-specific staining issues when using NR2F6 antibodies in immunohistochemistry?

Non-specific staining is a common challenge in NR2F6 immunohistochemistry that can be addressed through these methodical approaches:

• Identify the nature of non-specific staining:

  • Nuclear non-specificity: May indicate cross-reactivity with other nuclear receptors

  • Cytoplasmic background: Often due to hydrophobic interactions or Fc receptor binding

  • Stromal background: Can result from endogenous peroxidase or biotin activity

• Optimize blocking conditions:

  • For nuclear non-specificity: Add 5-10% normal serum from antibody host species

  • For Fc receptor issues: Include specific Fc receptor blocking reagents

  • For hydrophobic interactions: Add 0.1-0.3% Triton X-100 or 0.05% Tween-20 to blocking buffer

• Antibody dilution optimization:

  • Perform systematic titration experiments (1:50 to 1:500 range recommended for NR2F6)

  • Higher dilutions often reduce background but may compromise specific signal

  • Consider extended primary antibody incubation (overnight at 4°C) with higher dilutions

• Antigen retrieval modifications:

  • For NR2F6, test both recommended methods:

    • TE buffer at pH 9.0 (primary recommendation)

    • Citrate buffer at pH 6.0 (alternative)

  • Adjust retrieval duration (10-30 minutes) to optimize signal-to-noise ratio

• Validate with multiple controls:

  • Omit primary antibody (secondary antibody control)

  • Use isotype control at same concentration as primary antibody

  • If available, include tissue from NR2F6 knockout models

  • Use competitive blocking with immunizing peptide

• Detection system considerations:

  • Switch between HRP-polymer and biotin-free detection systems

  • For weak signals with high background, consider tyramide signal amplification

  • Adjust substrate development time to optimize signal-to-noise ratio

When documenting these optimization steps, create a detailed troubleshooting matrix that records each condition tested and the resulting signal quality to systematically improve protocol reliability.

What strategies can resolve inconsistent results when quantifying NR2F6 expression in tumor samples?

Inconsistent results in quantifying NR2F6 expression in tumor samples can arise from multiple sources. Here's a systematic approach to resolve these issues:

• Pre-analytical variables:

  • Standardize tissue preservation methods (flash-freezing for protein/RNA, formalin-fixation for IHC)

  • Control fixation time (18-24 hours optimal) for FFPE samples

  • Document cold ischemia time and minimize variation between samples

  • Use tumor-content assessment to normalize for stromal contamination

• Technical standardization for Western blotting:

  • Implement strict protein quantification protocols (BCA assay with standard curves)

  • Use loading controls appropriate for nuclear proteins (Lamin B1 rather than β-actin)

  • Consider nuclear extraction protocols to enrich for NR2F6

  • Employ fluorescence-based Western detection for more accurate quantification

  • Research finding: NR2F6 protein detection by Western blot typically shows a band at 43 kDa

• RNA expression quantification:

  • Design primers spanning exon-exon junctions to avoid genomic DNA amplification

  • Validate qPCR efficiency using standard curves from serial dilutions

  • Use multiple reference genes validated for stability in tumor samples

  • Consider digital droplet PCR for absolute quantification in heterogeneous samples

• IHC quantification standardization:

  • Implement digital pathology with automated scoring algorithms

  • Use H-score method (intensity × percentage positive cells) for semiquantitative assessment

  • Include calibration slides with known NR2F6 expression in each batch

  • Consider multiplex IHC to correlate NR2F6 with cell type markers in heterogeneous samples

• Cell type heterogeneity considerations:

  • Research finding: NR2F6 is expressed in immune cells, tumor cells, and stromal cells

  • Solution: Use single-cell approaches (single-cell RNA-seq, flow cytometry, multiplex IHC) to resolve cell type-specific expression

  • For bulk analysis, employ computational deconvolution algorithms to estimate cell type contributions

• Cross-validation between methodologies:

  • Compare protein (Western blot, IHC) and mRNA (qPCR, RNA-seq) quantification

  • Investigate discrepancies between methods to identify potential post-transcriptional regulation

  • Consider activity assays (e.g., NR2F6 Transcription Factor Activity Assay) to complement expression data

Implementing these strategies can significantly improve reproducibility and accuracy when quantifying NR2F6 expression across different tumor samples and experimental conditions.

How can NR2F6 knockout/knockdown models be effectively validated using NR2F6 antibodies?

Rigorous validation of NR2F6 knockout/knockdown models requires comprehensive antibody-based approaches:

• Western blot validation strategy:

  • Compare NR2F6 protein levels in wild-type versus knockout/knockdown samples

  • Use multiple antibodies targeting different epitopes when possible

  • Include positive controls (cell lines with known NR2F6 expression: HCT 116, HeLa, MCF-7)

  • Quantify signal reduction in knockdown models (aim for >80% reduction for functional studies)

  • Research precedent: NR2F6 knockdown was validated by immunoblotting in melanoma studies

• Immunofluorescence/IHC validation:

  • Assess complete loss of nuclear staining in knockout models

  • For knockdown models, quantify reduction in staining intensity

  • Co-stain with markers of cell types known to express NR2F6

  • Research application: Immunofluorescence was used to validate NR2F6 knockout in tumor infiltrating CD8+ T cells

• Functional validation assays:

  • For immune cell models: Measure IL-17 and IL-2 production (known to be suppressed by NR2F6)

  • For tumor models: Assess changes in proliferation, invasion, and immune cell infiltration

  • Research finding: NR2F6 KO mice exhibited hyperreactive lymphocytes

• Genetic validation complementation:

  • Re-express NR2F6 in knockout cells to rescue phenotype

  • Use antibodies to confirm successful re-expression

  • Include functionally dead mutants (e.g., DNA-binding domain mutants) as controls

• Single-cell validation approaches:

  • Flow cytometry with intracellular staining for NR2F6

  • Mass cytometry (CyTOF) for simultaneous detection of NR2F6 and cell type markers

  • Research finding: Flow cytometry revealed NR2F6 expression changes in different immune cell populations

These validation approaches ensure that phenotypes observed in NR2F6 knockout/knockdown models are specifically attributable to loss of NR2F6 function rather than off-target effects or compensatory mechanisms.

What are the most promising therapeutic approaches targeting NR2F6, and how can antibodies facilitate their development?

NR2F6-targeted therapeutic approaches represent an emerging area in cancer immunotherapy, with NR2F6 antibodies playing crucial roles in their development:

• Small molecule inhibitors of NR2F6:

  • Target identification: Crystal structures of NR2F6 guide rational drug design

  • Screening approach: Use NR2F6 transcription factor activity assays to evaluate compound efficacy

  • Validation approach: Antibodies confirm target engagement via cellular thermal shift assays (CETSA)

  • Research precedent: NR2F6 inhibition showed synergy with anti-PD1 therapy in melanoma models

• Degrader technologies (PROTACs):

  • Mechanism: Protein degradation rather than functional inhibition

  • Validation: Western blot with NR2F6 antibodies confirms protein depletion

  • Advantage: May overcome compensatory upregulation of transcription

  • Application: Useful for nuclear transcription factors that are challenging to inhibit with traditional approaches

• T cell engineering approaches:

  • Strategy: CRISPR-mediated knockout of NR2F6 in tumor-infiltrating lymphocytes or CAR-T cells

  • Validation: Flow cytometry with intracellular NR2F6 antibody staining

  • Research basis: NR2F6 deficiency enhances T cell activation and cytokine production

  • Therapeutic relevance: NR2F6 KO mice showed enhanced anti-tumor immunity

• Combination therapy development:

  • Approach: Combine NR2F6 targeting with established immune checkpoint inhibitors

  • Research finding: Delay of melanoma development was further enhanced by combining NR2F6 inhibition with anti-PD1 therapy

  • Biomarker development: IHC with NR2F6 antibodies to identify patients likely to respond

  • Mechanistic studies: Multiplex IHC to assess changes in tumor microenvironment

• Patient stratification biomarkers:

  • Application: NR2F6 expression analysis for clinical trial enrollment

  • Method: IHC scoring systems calibrated against outcome data

  • Research basis: NR2F6 expression in melanoma correlates with immunotherapy response

  • Implementation: Standardized IHC protocols with automated scoring systems

NR2F6 antibodies are essential tools in all these approaches, from target validation and mechanism studies to patient selection and treatment monitoring, positioning them as critical reagents in the translational research pipeline.

How does NR2F6 expression change during immune cell differentiation and activation, and what methods best capture these dynamics?

NR2F6 expression undergoes significant changes during immune cell differentiation and activation, which can be characterized using several complementary approaches:

• Temporal expression dynamics:

  • Research finding: Decrease of NR2F6 mRNA expression was associated with T cell activation, suggesting a silencing effect on NR2F6 gene transcription by TCR-mediated signaling pathways

  • Methods to measure kinetics:

    • Time-course qRT-PCR for mRNA changes

    • Western blot time series for protein dynamics

    • Flow cytometry with intracellular NR2F6 staining at multiple time points

• Cell type-specific expression patterns:

  • Research finding: NR2F6 is expressed in the thymus, spleen, lymph node, and bone marrow, as well as in CD3+ T and CD19+ B lymphocytes

  • Analysis approaches:

    • Single-cell RNA-seq to map expression across immune cell subtypes

    • Mass cytometry (CyTOF) with NR2F6 antibodies and lineage markers

    • Sorted cell populations analyzed by Western blot or qRT-PCR

• Subcellular localization changes:

  • Hypothesis: NR2F6 may undergo nuclear-cytoplasmic shuttling during activation

  • Methods to assess:

    • Subcellular fractionation followed by Western blot

    • Immunofluorescence microscopy with quantitative image analysis

    • Live-cell imaging with fluorescently tagged NR2F6

• Post-translational modifications:

  • Research question: Does NR2F6 undergo modifications after immune activation?

  • Experimental approaches:

    • Immunoprecipitation with NR2F6 antibodies followed by mass spectrometry

    • Phospho-specific antibodies if key modification sites are identified

    • Mobility shift analysis in Western blots after various treatments

• Functional consequences of expression changes:

  • Research finding: NR2F6-deficient mice had hyperreactive lymphocytes, developed late-onset immunopathology, and were hypersusceptible to Th17-dependent experimental autoimmune encephalomyelitis

  • Methods to correlate expression with function:

    • Cytokine production assays (especially IL-17 and IL-2)

    • ChIP-seq at different activation time points

    • Transcriptomic analysis of NR2F6 wild-type vs. knockout cells during activation

Understanding these dynamics is crucial for developing therapeutic strategies that target NR2F6 in a context-dependent manner, particularly for autoimmune diseases and cancer immunotherapy.

What is the relationship between NR2F6 and other immune checkpoints in the tumor microenvironment?

The relationship between NR2F6 and other immune checkpoints represents a critical frontier in cancer immunology research:

• Co-expression patterns:

  • Research finding: NR2F6 was found to be significantly correlated with other immune checkpoint inhibitors in glioma

  • Analysis approaches:

    • Multiplex IHC to visualize co-expression at single-cell level

    • Correlation analysis of RNA-seq data across multiple cancer types

    • Flow cytometry to identify cell populations co-expressing multiple checkpoints

• Functional interactions and redundancy:

  • Research finding: Combination of NR2F6 inhibition with anti-PD1 therapy showed enhanced efficacy in delaying melanoma development

  • Experimental strategies:

    • Combinatorial knockout/inhibition studies in preclinical models

    • Phospho-flow analysis of T cell signaling with single and combined targeting

    • Transcriptomic profiling to identify unique and overlapping gene signatures

• Mechanistic relationships:

  • Hypothesis: NR2F6 may regulate expression of other checkpoint molecules

  • Investigation approaches:

    • ChIP-seq to determine if NR2F6 directly binds promoters of other checkpoints

    • Analysis of checkpoint molecule expression in NR2F6-deficient vs. wild-type cells

    • Signaling pathway analysis to identify convergence points

• Cell type-specific interactions:

  • Research finding: NR2F6 is expressed in immune cells, tumor cells, and stromal cells within the tumor microenvironment

  • Methods to dissect cell-specific roles:

    • Conditional knockout models targeting specific cell populations

    • Single-cell RNA-seq and spatial transcriptomics

    • Cell type-specific ChIP-seq using labeled NR2F6 in specific populations

• Translational implications:

  • Research question: Can NR2F6 expression predict resistance to established checkpoint inhibitors?

  • Approaches:

    • Retrospective analysis of NR2F6 expression in responders vs. non-responders to ICT

    • Development of predictive biomarker panels including NR2F6 and other checkpoints

    • Preclinical testing of sequential vs. simultaneous targeting strategies

Understanding these relationships is essential for rational design of combination immunotherapies and patient stratification strategies in the evolving landscape of cancer immunotherapy.