IL23R Antibody

What is IL23R and why is it an important research target?

IL23R (Interleukin 23 Receptor) is a 629 amino acid protein with a molecular weight of approximately 71.7 kilodaltons that functions as a novel subunit of the receptor for cytokine IL23A/IL23. It forms a heterodimeric receptor complex by pairing with IL12RB1/IL12R beta 1, which is essential for IL23A signaling . Signal transduction analysis has confirmed that IL23R associates constitutively with Janus kinase 2 (JAK2) and binds to transcription activator STAT3 in a ligand-dependent manner .

IL23R has gained significant research interest because:

• It plays a crucial role in the pathogenesis of several inflammatory diseases, including psoriasis and inflammatory bowel disease (IBD)

• It is necessary for the generation of Th17 cells, though interestingly not required for maintaining previously generated Th17 cells

• Genetic variants and mutations in the IL23R gene have been associated with autoimmunity

• It has emerging importance in tumor biology and cancer immunology research

How do I select the appropriate IL23R antibody for my specific research application?

Selecting the optimal IL23R antibody requires consideration of multiple factors:

• Target species reactivity: Determine if you need an antibody reactive to human, mouse, rat, or multiple species, based on your experimental model. Available antibodies have varying reactivity profiles, with some specific to a single species while others demonstrate cross-reactivity across human, mouse, and rat IL23R .

• Application compatibility: Different antibodies are validated for specific applications:

  • Western Blot (WB): Most IL23R antibodies are validated for WB, with recommended dilutions typically ranging from 1:500 to 1:2000

  • Immunohistochemistry (IHC): Several antibodies work for paraffin-embedded tissues (IHC-P)

  • Flow cytometry (FCM): Specialized clones like 12B2B64 are specifically validated for flow cytometry applications

  • ELISA, Immunofluorescence (IF), and other applications

• Antibody format:

  • Polyclonal antibodies: Offer broader epitope recognition but potentially more background

  • Monoclonal antibodies: Provide high specificity for a single epitope

  • Conjugated vs. unconjugated: Determine if you need a directly labeled antibody

• Epitope region: Consider which domain of IL23R you wish to target. Available antibodies target various regions:

  • N-terminal region (AA 15-125)

  • Middle region (AA 401-550)

  • C-terminal region (AA 510-629)

• Validation data: Review available validation data, including Western blot images showing the expected band size (~58-72 kDa depending on glycosylation) .

What are the optimal conditions for detecting IL23R by Western blot?

Successful Western blot detection of IL23R requires careful optimization of several parameters:

• Sample preparation:

  • Cell types: K562 human chronic myelogenous leukemia cell line has been validated as a positive control for IL23R expression

  • Lysis conditions: Use RIPA buffer with protease inhibitors to effectively extract membrane-bound IL23R

  • Sample quantity: Load 20-30 μg of total protein per lane

• Electrophoresis conditions:

  • Reducing vs. non-reducing: Many IL23R antibodies perform better under non-reducing conditions

  • Expected molecular weight: Detect IL23R at approximately 58-72 kDa (depending on post-translational modifications)

• Transfer and detection protocol:

  • Transfer to PVDF membrane (preferred over nitrocellulose for IL23R)

  • Blocking: 5% non-fat dry milk or BSA in TBST for 1 hour at room temperature

  • Primary antibody: Dilute to manufacturer's recommendation (typically 1:500-1:2000)

  • Incubation: Overnight at 4°C gives optimal results

  • Secondary antibody: HRP-conjugated anti-species IgG (e.g., anti-rabbit or anti-mouse depending on primary)

  • Detection: Enhanced chemiluminescence (ECL) systems work well for IL23R visualization

• Troubleshooting guidance:

  • Multiple bands: May represent glycosylation variants or splice isoforms (IL23R has six known splice variants)

  • No signal: Consider using fresh positive control lysates, as IL23R can degrade with repeated freeze-thaw cycles

How can I optimize flow cytometry protocols for IL23R detection on different immune cell populations?

Optimizing flow cytometry for IL23R detection requires special consideration:

• Cell preparation:

  • Fresh vs. fixed cells: While fresh cells are preferred, mild fixation (2% paraformaldehyde for 10 minutes) can preserve IL23R epitopes

  • Permeabilization: Not typically required as IL23R is primarily expressed on the cell surface

  • Cell concentration: 1 × 10^6 cells per 100 μL is optimal

• Staining protocol optimization:

  • Buffer composition: PBS with 1-2% BSA and 0.1% sodium azide works well

  • Antibody titration: Critical step - for clone 12B2B64, ≤0.75 μg per million cells in 100 μl volume is recommended

  • Incubation conditions: 30 minutes at 4°C in the dark

  • Washing steps: Minimum of 2 washes with staining buffer

• Panel design considerations:

  • IL23R expression is heterogeneous across immune cell populations

  • Co-staining with CD4, CD8, γδTCR, and CD161 helps identify specific IL23R+ subsets

  • Include lineage markers for specific analysis of Th17, ILC3, and γδ T cell populations

• Controls to include:

  • Fluorescence minus one (FMO) controls are essential for accurate gating

  • Isotype controls (rat IgG2b, κ for clone 12B2B64)

  • Biological negative and positive controls (stimulated vs. unstimulated cells)

• Troubleshooting guide:

  • Low detection: IL23R is often expressed at relatively low levels; consider using signal amplification systems

  • Background issues: Optimize blocking and use high-quality Fc block

How do I interpret contradictory IL23R expression data between different detection methods?

Researchers often encounter discrepancies in IL23R expression data between techniques like qPCR, Western blot, and flow cytometry. Systematic approach to resolving these contradictions:

• Understanding method-specific limitations:

  • qPCR measures mRNA but not protein expression or splice variants

  • Western blotting detects denatured protein but may not distinguish cell-specific expression

  • Flow cytometry measures surface expression on specific cell populations but may be affected by receptor internalization

• Reconciliation strategies:

  • Compare antibody epitopes: Different antibodies may recognize different IL23R domains or isoforms

  • Evaluate post-translational modifications: Glycosylation affects antibody binding and apparent molecular weight

  • Consider activation state: IL23R expression is dynamically regulated by cell activation status

  • Account for splice variants: The six known splice isoforms of IL23R have different functional properties

• Validation recommendations:

  • Use multiple antibody clones targeting different epitopes

  • Combine protein and mRNA detection methods

  • Include genetic knockdown/knockout controls

  • Use IL23R-transfected cell lines as positive controls

• Data integration framework:

  • Start with most sensitive/specific method for your biological question

  • Use orthogonal methods to confirm key findings

  • Report discrepancies transparently in publications

What are the best approaches for studying IL23R signaling dynamics in primary immune cells?

Studying IL23R signaling dynamics requires sophisticated methodological approaches:

• Cell isolation and culture conditions:

  • Primary T cells, NK cells, and myeloid cells express IL23R under specific conditions

  • For Th17 induction: Naive CD4+ T cells require IL-6, TGF-β, and IL-1β before IL23R becomes detectable

  • Polarization protocols must be optimized for each species (human vs. mouse)

• Signaling pathway analysis:

  • JAK2 and STAT3 phosphorylation monitoring by phospho-flow or Western blot

  • Time-course experiments: IL23R signaling shows biphasic dynamics with early (minutes) and late (hours) events

  • Dose-response studies: Use recombinant IL-23 at 1-100 ng/mL range

• Advanced analytical techniques:

  • Single-cell analysis: Reveals heterogeneity in IL23R expression and signaling

  • Proximity ligation assays: Detect IL23R interaction with JAK2 in intact cells

  • CRISPR-based screening: Identify novel components of IL23R signaling network

• Signaling crosstalk investigations:

  • IL23R interacts functionally with other cytokine receptors, particularly IL-1R and IL-6R

  • Co-immunoprecipitation followed by mass spectrometry can identify novel interacting partners

  • Inhibitor studies help delineate pathway specificity

How can IL23R antibodies be used to evaluate the efficacy of IL-23 pathway-targeting therapies?

IL23R antibodies serve as critical tools for evaluating IL-23 pathway-targeting therapeutics:

• Pharmacodynamic biomarker applications:

  • Monitor IL23R expression levels before and after therapeutic intervention

  • Assess receptor occupancy using competing and non-competing antibody clones

  • Evaluate downstream signaling (pSTAT3) to confirm pathway inhibition

• Target cell population analysis:

  • Multiparameter flow cytometry with IL23R antibodies helps identify which immune cell populations are affected by therapy

  • Single-cell RNA-seq paired with protein-level IL23R detection provides comprehensive insights

• Predictive biomarker development:

  • IL23R polymorphism detection (R381Q variant is protective in IBD)

  • Baseline IL23R expression patterns may predict response to anti-IL23 therapies

  • IL23R+ cell frequency monitoring during treatment can indicate therapeutic efficacy

• Translational research applications:

  • Ex vivo testing of patient samples before and during treatment

  • Tissue-specific analysis using IL23R immunohistochemistry in affected organs

  • Correlation of receptor expression with clinical outcomes

What methodological approaches best distinguish effects of IL-12/23 dual inhibition versus selective IL-23 inhibition?

With the development of both dual IL-12/23 inhibitors and selective IL-23 inhibitors, distinguishing their effects requires sophisticated methodological approaches:

• Comparative receptor analysis:

  • IL23R antibodies detect specific targeting of the IL-23 pathway

  • Combined analysis with IL12RB1 and IL12RB2 antibodies helps differentiate pathway-specific effects

  • Receptor complex formation analysis by co-immunoprecipitation or proximity ligation

• Downstream signaling differentiation:

  • IL-12 primarily activates STAT4, while IL-23 activates STAT3

  • Multiplex phospho-flow cytometry can simultaneously assess both pathways

  • Time-course analysis reveals distinct kinetics of pathway inhibition

• Functional outcome measurements:

  • Th1 vs. Th17 differentiation assays

  • Cytokine profiling (IFN-γ vs. IL-17A/F and IL-22)

  • Transcriptional analysis focusing on pathway-specific gene signatures

• Model systems for comparative analysis:

  • Humanized mouse models expressing human IL23R

  • Ex vivo tissue cultures from inflammatory disease patients

  • Organoid systems incorporating immune components

• Clinical translation considerations:

  • Recent data suggests similar efficacy of selective IL-23 inhibition compared to dual IL-12/23 blockade in IBD with potentially fewer adverse events

  • Biomarker-driven approaches may soon guide clinicians to prescribe anti-IL-23 therapies to patients most likely to respond

What are the most common technical issues with IL23R antibodies and how can they be resolved?

Researchers frequently encounter technical challenges when working with IL23R antibodies:

• Sensitivity issues:

  • Problem: Low detection of endogenous IL23R

  • Solution: Signal amplification systems (tyramide signal amplification for IHC/IF), more sensitive detection methods (SuperSignal West Femto for WB), or cell activation to upregulate IL23R expression

• Specificity concerns:

  • Problem: Multiple bands in Western blot or nonspecific staining

  • Solution: Validate with positive and negative controls (including genetic knockouts if available), use multiple antibodies targeting different epitopes, optimize blocking conditions (5% milk or BSA)

• Reproducibility challenges:

  • Problem: Inconsistent results between experiments

  • Solution: Standardize protocols, use freshly reconstituted antibody (0.5 mg/mL in sterile PBS recommended) , store antibody solution undiluted between 2°C and 8°C

• Application-specific troubleshooting:

  • Flow cytometry: Optimize compensation, use viability dyes to exclude dead cells, consider alternative clones (12B2B64 performs well in flow cytometry)

  • IHC: Test different antigen retrieval methods, optimize antibody concentration (1:50 - 1:200 dilution recommended for IHC-P)

  • Western blot: Try both reducing and non-reducing conditions, as some IL23R epitopes are sensitive to reduction

How can researchers validate the specificity of IL23R antibodies in their experimental systems?

Rigorous validation of IL23R antibodies is essential for generating reliable research data:

• Genetic validation approaches:

  • CRISPR/Cas9 knockout of IL23R as negative control

  • siRNA/shRNA knockdown to demonstrate reduced signal

  • Overexpression systems as positive controls

• Peptide competition assays:

  • Pre-incubate antibody with immunizing peptide

  • Should abolish specific signal in all applications

  • Requires knowledge of the immunogen (e.g., recombinant fusion protein containing amino acids 510-629 of human IL23R)

• Multi-antibody concordance testing:

  • Use antibodies from different suppliers targeting distinct epitopes

  • Compare staining patterns across applications

  • Consistent results increase confidence in specificity

• Cross-species reactivity assessment:

  • Test antibody in multiple species if claimed to be cross-reactive

  • Some antibodies show reactivity to human, mouse, and rat IL23R, while others are species-specific

  • Note that some clones (like 218213) do not cross-react with recombinant mouse IL-23R

• Application-specific validation:

  • Western blot: Verify molecular weight (approximately 58-72 kDa depending on glycosylation)

  • Flow cytometry: Use appropriate biological controls (stimulated vs. unstimulated cells)

  • IHC/IF: Include tissue from IL23R-deficient animals or IL23R-low expressing tissues

By implementing these validation strategies, researchers can ensure the reliability and reproducibility of their IL23R antibody-based experiments, ultimately strengthening the quality of their research findings.