IL13RA1 Antibody

What is IL13RA1 and what is its biological significance?

IL13RA1 (Interleukin-13 receptor subunit alpha-1) is a type 1 membrane protein belonging to the hemopoietin receptor family. It functions as one of two proteins capable of binding IL-13, with IL13RA1 showing lower affinity compared to IL13RA2. The human IL13RA1 cDNA encodes a 427 amino acid precursor protein with a 21 amino acid signal peptide, 324 amino acid extracellular domain, 23 amino acid transmembrane region, and 59 amino acid cytoplasmic tail. Human and mouse IL13RA1 share 76% amino acid sequence identity .

Functionally, IL13RA1 combines with IL-4R alpha to form a high-affinity receptor complex capable of transducing IL-13-dependent proliferative signals. This receptor complex plays a critical role in mediating cellular responses to IL-13, particularly in inflammatory processes .

Which cell types express IL13RA1 and how is expression detected?

IL13RA1 is expressed in multiple cell types across different tissues. In the immune system, human peripheral blood granulocytes express detectable levels of IL13RA1 as demonstrated by flow cytometry using PE-conjugated monoclonal antibodies . Recent research has also revealed that IL13RA1 is expressed in brain dopaminergic (DA) neurons, which are the same neurons lost in Parkinson's disease .

The expression of IL13RA1 in epithelial cells is also well-documented. Studies of Il13ra1-deficient mice showed alteration of epithelial cell-associated genes, suggesting that IL13RA1 plays a role in epithelial cell function. Flow cytometry represents a reliable method for detecting IL13RA1 in various cell populations, with the use of appropriate fluorophore-conjugated antibodies .

How does IL13RA1 differ from IL13RA2?

The two IL-13 binding proteins (IL13RA1 and IL13RA2) differ primarily in their binding affinity and signaling capabilities:

IL13RA1 has been well-characterized for its ability to form a signaling complex with IL-4R alpha, whereas the precise signaling role of IL13RA2 remains an active area of investigation .

What role does IL13RA1 play in neurodegenerative diseases?

Recent research has identified intriguing connections between IL13RA1 and neurodegenerative disorders, particularly Parkinson's disease (PD). Studies have shown that IL13RA1 is expressed in brain dopaminergic (DA) neurons—the same neurons that undergo degeneration in PD. More significantly, research indicates that IL13RA1 increases the susceptibility of these neurons to oxidative damage in inflammatory models .

This finding suggests that IL13RA1 may contribute to the pathogenesis and progression of PD. Current research aims to determine the extent to which IL13RA1 contributes to PD progression by comparing dopaminergic neuron survival in pre-clinical models with and without IL13RA1 expression following MPTP treatment (a neurotoxin that produces PD-like symptoms) .

The "IL-13 system" may represent a novel therapeutic target for Parkinson's disease. Given that compounds targeting this system are already under development for allergic reactions, this pathway offers potential for therapeutic intervention in neurodegenerative conditions .

How does IL13RA1 function in lung homeostasis and injury?

Contrary to initial expectations, IL13RA1 demonstrates a protective role in lung homeostasis and injury response. Studies using bleomycin-induced lung injury models have revealed that Il13ra1-deficient mice display exacerbated disease outcomes. This protective function appears to involve both structural and hematopoietic cells .

Under normal homeostatic conditions, Il13ra1-deficient mice showed marked alterations in 14 lung transcripts. Unbiased STRING analysis revealed that 5 of these 14 genes were "hallmark" epithelial cell-associated genes including:

• Chloride channel calcium activated, family member 3 (Clca3/Gob5) - 17.28-fold decrease

• Relm-α (Retnla) - 2.37-fold decrease

• Anterior gradient 2 (Agr2) - 2.14-fold decrease

• Chitinase 3-like 4 (Chi3l4) - 2.11-fold decrease

• Trefoil factor 2 (Tff2) - 2.58-fold decrease

Following bleomycin treatment, Il13ra1-deficient mice showed specific alterations in 467 genes that were not observed in wild-type mice, indicating that IL13RA1 significantly contributes to the gene expression profile during lung injury response .

What are the cellular sources of IL13RA1 activators in neuroinflammatory processes?

Two primary cytokines—IL-13 and IL-4—function as endogenous activators of IL13RA1 signaling. Current research aims to identify the specific cellular sources of these activators in neuroinflammatory contexts. Understanding which cells produce these cytokines and the temporal dynamics of their expression is crucial for developing targeted therapeutic strategies .

In pre-clinical models of Parkinson's disease, researchers are specifically investigating the cellular source and time course of IL-13 and IL-4 expression following MPTP treatment. This research is essential for understanding the complete signaling pathway through which IL13RA1 influences neuroinflammation and neurodegeneration .

What are optimal protocols for detecting IL13RA1 expression using flow cytometry?

For optimal detection of IL13RA1 using flow cytometry, researchers should consider the following protocol elements:

• Sample preparation: When working with human peripheral blood, separate granulocytes using standard density gradient centrifugation methods.

• Antibody selection: Use fluorophore-conjugated monoclonal antibodies specific to IL13RA1. For example, Mouse Anti-Human IL-13 Ra1 PE-conjugated Monoclonal Antibody (such as FAB1462P) has been validated for this purpose .

• Controls: Always include appropriate isotype controls (e.g., IC0041P for mouse antibodies) to accurately assess background staining .

• Co-staining markers: Consider using additional markers to identify specific cell populations. For example, when working with granulocytes, researchers have successfully co-stained with Mouse Anti-Human Siglec-3/CD33 APC-conjugated Monoclonal Antibody .

• Analysis parameters: Visualize results using histogram overlays comparing the specific antibody staining (filled histogram) against isotype control (open histogram) .

For detailed membrane-associated protein staining protocols, researchers should consult established protocols from antibody manufacturers.

What considerations should be made when designing experiments with IL13RA1 knockout models?

When designing experiments with IL13RA1 knockout models (Il13ra1−/− mice), researchers should account for several important factors:

• Baseline phenotypic differences: Il13ra1−/− mice display altered expression of multiple genes even under homeostatic conditions, particularly epithelial cell-associated genes. These baseline differences must be considered when interpreting experimental results .

• Tissue-specific effects: IL13RA1 deficiency affects different tissues in distinct ways. For example, in lung tissue, IL13RA1 deficiency leads to specific alterations in epithelial cell gene expression .

• Apoptosis dynamics: In bleomycin-induced lung injury models, while initial epithelial cell apoptosis is equivalent between wild-type and Il13ra1−/− mice, differences emerge by 72 hours post-treatment. At this timepoint, apoptosis persists in wild-type epithelial cells but is nearly absent in Il13ra1−/− mice .

• Compensatory mechanisms: Consider potential upregulation of alternative pathways in knockout models. Research has shown that increased pathology in Il13ra1−/− mice was not due to increased responsiveness to IL-17, IL-4, IL-13, increased IL-13Rα2, or type 1 IL-4R signaling .

• Cell type-specific contributions: Use chimeric models or conditional knockouts to determine whether observed phenotypes are due to IL13RA1 expression in structural or hematopoietic cells .

How can researchers validate the specificity of IL13RA1 antibodies?

Validating antibody specificity is crucial for obtaining reliable research results. For IL13RA1 antibodies, consider the following validation approaches:

• Western blot analysis: High-quality IL13RA1 antibodies should detect a band at approximately 49 kDa in human samples .

• Knockout controls: Compare staining between wild-type and IL13RA1 knockout models to confirm specificity.

• Multiple application validation: Select antibodies validated across multiple applications such as Western blot, immunohistochemistry, flow cytometry, and ELISA as appropriate for your research questions .

• Matched antibody pairs: For quantitative assays such as ELISA or cytometric bead arrays, use validated matched antibody pairs. For example, the 84525-3-PBS capture and 84525-2-PBS detection pair has been validated for cytometric bead array applications .

• Cross-reactivity testing: Confirm that the antibody does not cross-react with IL13RA2 or other similar proteins.

• Antibody purification: Opt for affinity-purified antibodies with high purity (>95% by SDS-PAGE) to minimize nonspecific binding .

What experimental designs best elucidate IL13RA1's role in neurodegeneration?

To investigate IL13RA1's role in neurodegeneration, particularly in Parkinson's disease models, researchers should consider these experimental approaches:

• Comparative neurotoxin studies: Measure and compare dopaminergic neuron numbers in pre-clinical models with or without IL13RA1 expression following MPTP treatment. MPTP is particularly valuable as it causes a syndrome clinically and pathologically similar to PD .

• Neuroinflammatory response characterization: Perform comparative evaluation of the neuroinflammatory response associated with neurotoxin treatment in IL13RA1-sufficient and IL13RA1-deficient models .

• Cytokine expression profiling: Determine the cellular source and time course of IL-13 and IL-4 expression following neurotoxin treatment to understand the activation dynamics of IL13RA1 signaling .

• Oxidative stress markers: Measure markers of oxidative damage in dopaminergic neurons with and without IL13RA1 expression to confirm the hypothesis that IL13RA1 increases susceptibility to oxidative damage .

• Intervention studies: Test compounds that block IL-13 signaling for their potential to protect dopaminergic neurons from degeneration .

How should researchers address inconsistent IL13RA1 antibody staining results?

Inconsistent staining results can undermine research validity. To address this issue:

• Storage and handling: Ensure proper antibody storage by protecting IL13RA1 antibodies from light and storing at 2-8°C. Do not freeze the antibodies, as this can affect their performance .

• Titration and optimization: Determine optimal antibody dilutions for each specific application. As noted in product literature, "Optimal dilutions should be determined by each laboratory for each application" .

• Sample preparation: Ensure consistent sample preparation methods, particularly for membrane proteins like IL13RA1.

• Positive and negative controls: Include appropriate positive controls (tissues/cells known to express IL13RA1) and negative controls (isotype controls and IL13RA1-deficient samples) in each experiment.

• Batch consistency: When possible, use the same lot of antibody for related experiments to minimize batch-to-batch variation. Recombinant antibody production technologies can provide "unrivalled batch-to-batch consistency" .

What are the most significant contradictions in IL13RA1 research findings?

Research on IL13RA1 has revealed some apparently contradictory findings that researchers should be aware of:

• Protective vs. pathogenic roles: While IL13RA1 appears to increase the susceptibility of dopaminergic neurons to oxidative damage in inflammatory models (suggesting a pathogenic role) , it also demonstrates a protective role in bleomycin-induced lung injury (suggesting a protective function) .

• Cell type-specific effects: IL13RA1 may have different or even opposing functions depending on the cell type and tissue context, requiring careful consideration when extrapolating findings across different experimental systems.

• Initial vs. later responses: The temporal dynamics of IL13RA1's role in injury response may be complex. For example, in bleomycin-induced lung injury, Il13ra1-deficient mice showed equivalent initial epithelial cell apoptosis but decreased apoptosis at later timepoints compared to wild-type mice .

• Receptor complex interactions: The interaction between IL13RA1 and other receptor components (such as IL-4R alpha) adds complexity to the interpretation of research findings, as effects attributed to IL13RA1 may actually result from altered receptor complex formation .

Understanding these nuances is essential for designing experiments that accurately characterize IL13RA1's biological functions.

What emerging technologies could advance IL13RA1 research?

Several emerging technologies hold promise for advancing IL13RA1 research:

• Single-cell analysis: Single-cell RNA sequencing and proteomics could reveal cell-specific IL13RA1 expression patterns and downstream effects that may be masked in bulk tissue analyses.

• CRISPR-Cas9 gene editing: Precise genetic manipulation of IL13RA1 in various cell types could help resolve cell-specific functions and identify critical protein domains.

• Recombinant antibody technology: The development of highly specific recombinant antibodies with improved batch-to-batch consistency offers advantages for long-term research programs .

• Advanced imaging: Super-resolution microscopy and intravital imaging could provide insights into IL13RA1 localization, trafficking, and interaction with signaling partners in living cells and tissues.

• Computational modeling: Systems biology approaches could help integrate complex datasets to predict IL13RA1 signaling outcomes in different cellular contexts.

How might IL13RA1-targeted therapies advance treatment of neurodegenerative diseases?

The potential for IL13RA1-targeted therapies in neurodegenerative diseases, particularly Parkinson's disease, represents an exciting frontier:

• Leveraging existing compounds: The IL-13 system is already an attractive drug target due to its role in mediating allergic reactions, with several compounds currently under development. These could potentially be repurposed for neurodegenerative conditions .

• Cell-specific targeting: Developing delivery systems that specifically target IL13RA1 in dopaminergic neurons could minimize off-target effects in other tissues where IL13RA1 may play protective roles.

• Combination approaches: IL13RA1-targeted therapies might be most effective when combined with other neuroprotective strategies, addressing multiple aspects of neurodegeneration simultaneously.

• Biomarker development: IL13RA1 and its ligands could potentially serve as biomarkers for disease progression or treatment response in neurodegenerative conditions.

• Preventive strategies: Understanding the role of IL13RA1 in neuroinflammation might enable the development of preventive interventions for individuals at risk for neurodegenerative diseases.