IL17E Mouse

What is mouse IL-17E and how does it differ from other IL-17 family members?

Mature mouse IL-17E shares 80% and 91% amino acid sequence identity with human and rat IL-17E, respectively . It binds to IL-17RB but also requires IL-17RA to exert its activity, activating a variety of cell types to increase production of Th2 cytokines . This cytokine functions as a mediator of allergic responses and provides protection against intestinal parasites through Th2-mediated mechanisms.

What are the primary cellular sources of IL-17E in mice?

In mice, IL-17E is predominantly expressed by:

• Intestinal and airway epithelial cells (during allergic reactions and helminth infections)

• Th2 cells

• Eosinophils

• Basophils

During helminth infections and allergic reactions, IL-17E is locally upregulated in these cell types, suggesting tissue-specific regulation of IL-17E expression . Expression patterns may differ based on the specific immune challenge, with epithelial cells serving as a critical early source during barrier disruption.

What receptors does mouse IL-17E interact with to mediate its effects?

Mouse IL-17E binds to IL-17RB (also known as IL-17Rh1), but requires IL-17RA as a co-receptor to exert its biological activity . This receptor complex differs from that used by IL-17A and IL-17F, explaining the distinct biological activities of IL-17E. The IL-17E/IL-17RB/IL-17RA signaling axis initiates distinct downstream signaling pathways that ultimately promote Th2 cytokine production and associated immune responses.

What are the recommended methods for reconstituting and storing recombinant mouse IL-17E protein?

Recombinant mouse IL-17E should be handled with specific protocols to maintain its biological activity:

For BSA-containing preparations:

• Reconstitute lyophilized protein at 100 μg/mL in sterile 4 mM HCl containing at least 0.1% human or bovine serum albumin

• Store at -20°C to -80°C after reconstitution

• Use a manual defrost freezer and avoid repeated freeze-thaw cycles

For carrier-free preparations:

• Reconstitute at 100 μg/mL in sterile 4 mM HCl

• Store at -20°C to -80°C after reconstitution

• Use a manual defrost freezer and avoid repeated freeze-thaw cycles

Both formulations are typically shipped at ambient temperature but should be stored immediately upon receipt at the recommended temperature.

How can I accurately measure IL-17E levels in mouse tissue and serum samples?

Several validated techniques can be used to measure mouse IL-17E levels:

• ELISA: DuoSet ELISA kits are available for mouse IL-17E detection in cell culture supernatants . For complex matrices like serum and plasma, additional optimization may be required. Typical sensitivity ranges are in the pg/mL range.

• Multiplex assays: Cytometric bead arrays or Luminex-based multiplex systems allow simultaneous detection of IL-17E along with other cytokines, ideal for limited sample volumes .

• Quantitative RT-PCR: For tissue samples, measuring IL-17E mRNA expression provides information about local cytokine production. This approach should be coupled with protein detection when possible, as mRNA and protein levels may not always correlate .

• Flow cytometry: For cellular sources of IL-17E, intracellular cytokine staining followed by flow cytometry can identify specific cell populations producing IL-17E.

Each method has specific advantages depending on your research question. For absolute quantification, ELISA remains the gold standard, while multiplex approaches offer broader cytokine profiling.

What are effective models for studying IL-17E function in mice?

Several validated approaches can be used to study IL-17E biology in mice:

• Transgenic overexpression: Forced expression of murine IL-17E induces growth retardation and leads to Th2-biased responses characterized by eosinophilia, increased serum IgE and IgG1, and elevated Th2 cytokines (IL-4, IL-5, IL-10, IL-13) .

• IL-17E knockout mice: These animals show impaired Th2 responses during helminth infection and allergic inflammation, providing insights into IL-17E's normal physiological roles.

• Recombinant protein administration: Systemic or local administration of recombinant IL-17E can induce acute Th2 responses. Effective dosing typically ranges from 0.25-1.5 ng/mL in vitro and varies by application in vivo .

• IL-17E expression in maternal immune activation models: Several studies have utilized maternal immune activation models using poly(I:C) (20 mg/kg) or LPS (0.05 mg/kg) at embryonic day 12.5 to study IL-17E in the context of neurodevelopmental disorders .

• Osmotic pump delivery: Subcutaneous osmotic pumps releasing IL-17E at a rate of 0.025 mg/kg per hour have been used to simulate chronic inflammation .

Selection of the appropriate model depends on your specific research question and whether you're studying acute responses, chronic conditions, or developmental effects.

How can I investigate the role of IL-17E in mouse models of allergic asthma?

To effectively study IL-17E in mouse models of allergic asthma, a multi-faceted approach is recommended:

• Timing of analysis: IL-17E plays different roles during sensitization versus challenge phases. Design experiments to distinguish between these phases by administering neutralizing antibodies or recombinant protein at specific timepoints.

• Cell-specific deletion: Use conditional knockout approaches (such as epithelial-specific deletion using CC10-Cre or Club cell-specific promoters) to determine the relative contribution of IL-17E from different cellular sources.

• Challenge protocols: Standard protocols include:

  • Ovalbumin (OVA) sensitization (10μg OVA with alum on days 0 and 14) followed by OVA aerosol challenge

  • House dust mite extract (25μg intranasally 3 times per week for 5 weeks)

  • IL-33 administration (0.5μg intranasally) to bypass initial sensing and focus on downstream effects

• Assessment methods:

  • Airway hyperresponsiveness using whole-body plethysmography or invasive measurements

  • Bronchoalveolar lavage fluid analysis for eosinophil counts and Th2 cytokines

  • Lung histopathology for mucus production (PAS staining) and inflammatory infiltrates

  • Flow cytometry of lung tissue to identify IL-17E-producing and IL-17E-responsive cells

• Comparison with IL-17A models: Include experimental groups that allow comparison between IL-17E (Th2-promoting) and IL-17A (Th17-promoting) effects to distinguish their relative contributions .

Suzukawa et al. demonstrated that epithelial cell-derived IL-25, rather than Th17 cell-derived IL-17 or IL-17F, is crucial for murine asthma, highlighting the importance of cellular source in these models .

What are the key considerations when studying IL-17E in neuroinflammatory conditions in mice?

When investigating IL-17E in neuroinflammatory conditions, several specialized approaches should be considered:

• Blood-brain barrier (BBB) considerations: Determine whether peripherally administered IL-17E crosses the BBB or acts on BBB endothelial cells to induce secondary mediators. Alternatively, central administration via intracerebroventricular injection may be necessary.

• Maternal immune activation (MIA) models: Multiple studies have used MIA models to study IL-17's role in neurodevelopmental disorders:

  • Poly(I:C) administration (20 mg/kg i.p.) at embryonic day 12.5

  • LPS administration (0.05 mg/kg i.p.) at embryonic day 12.5

• Timing of analysis: Assess IL-17E levels at different developmental stages (embryonic, postnatal, adult) as alterations may be age-dependent. Studies have shown varying IL-17 levels at postnatal days 1, 7, 14, and 30 .

• Tissue considerations: Analyze multiple compartments including:

  • Serum/plasma

  • Brain regions (cerebellum, hippocampus, cortex)

  • CSF (technically challenging in mice)

  • Placenta and maternal tissues when using pregnancy models

• Behavioral assessments: Correlate IL-17E levels with relevant behavioral outcomes such as social interaction tests, repetitive behaviors, and cognitive assessments to establish functional relevance.

One study found decreased IL-17 levels at postnatal day 30 in cerebellar lysates from a mouse model of MIA, suggesting age-dependent alterations that may inform timing of therapeutic interventions .

How do I differentiate between direct effects of IL-17E and secondary effects mediated by downstream cytokines?

Distinguishing direct IL-17E effects from those mediated by downstream cytokines requires specialized experimental approaches:

• In vitro stimulation with blocking antibodies: Stimulate target cells with recombinant IL-17E in the presence of neutralizing antibodies against potential downstream mediators (IL-4, IL-5, IL-13). This approach can reveal which effects persist when secondary signaling is blocked.

• Knockout comparison studies: Compare responses to IL-17E in wild-type mice versus those lacking key downstream cytokines (IL-4-/-, IL-13-/-, or STAT6-/- mice). Effects that persist in knockout models are likely direct IL-17E effects.

• Temporal analysis: Perform detailed time-course experiments measuring IL-17E and downstream cytokines. Direct effects typically occur earlier (within hours), while secondary effects develop later (12-72 hours).

• Cell-specific receptor deletion: Use conditional knockout approaches to delete IL-17RB in specific cell populations to determine which cell types mediate direct versus indirect effects.

• Signal transduction analysis: Direct IL-17E signaling activates specific pathways through Act1 and TRAF6. Phospho-flow cytometry or western blotting for these pathway components can identify cells directly responding to IL-17E.

Swaidani et al. demonstrated the critical role of epithelial-derived Act1 in IL-17E-mediated pulmonary inflammation, highlighting the importance of this signaling pathway in direct IL-17E effects .

Why might I observe discrepancies between IL-17E mRNA expression and protein levels in mouse models?

Several factors can contribute to discrepancies between IL-17E mRNA and protein measurements:

• Post-transcriptional regulation: IL-17E may be subject to microRNA regulation or RNA-binding protein interactions that affect translation efficiency without altering mRNA levels.

• Protein stability and secretion dynamics: IL-17E protein may be rapidly degraded or sequestered in certain tissues, leading to lower detection despite high mRNA expression.

• Technical limitations:

  • RT-PCR detection of mRNA may amplify partially degraded transcripts

  • ELISA antibodies may cross-react with related family members or detect biologically inactive fragments

  • Sample processing methods may affect protein recovery differently from RNA extraction

• Temporal dynamics: Peak mRNA expression often precedes peak protein production, so time-course analyses are essential to capture both events appropriately.

• Cellular compartmentalization: IL-17E may be produced in one tissue but act distantly, leading to discrepancies between sites of mRNA expression and protein detection.

To address these issues, use multiple detection methods, perform detailed time-course analyses, and consider using reporter mice where IL-17E expression is linked to a fluorescent protein for real-time monitoring.

What are common pitfalls when using recombinant mouse IL-17E in experimental systems?

Researchers working with recombinant mouse IL-17E should be aware of several potential pitfalls:

• Protein stability issues:

  • IL-17E can degrade with repeated freeze-thaw cycles

  • Activity may decrease over time even at recommended storage temperatures

  • Solution pH significantly affects stability (maintain in acidic buffer as recommended)

• Carrier protein interference:

  • Standard preparations contain BSA as a carrier protein

  • For applications where BSA may interfere, carrier-free versions should be used

  • Carrier-free preparations typically require more careful handling due to decreased stability

• Potency variations:

  • Biological activity can vary between batches

  • The effective concentration range for in vitro studies is 0.25-1.5 ng/mL; always perform dose-response curves with each new lot

  • Activity may appear weaker than human counterpart in some assays

• Receptor complexity:

  • IL-17E requires both IL-17RB and IL-17RA for signaling

  • Ensure target cells express both receptor components

  • Validate receptor expression before conducting signaling experiments

• Endotoxin contamination:

  • Even low levels of endotoxin can confound immunological experiments

  • Use endotoxin-tested preparations, especially for in vivo applications

  • Consider including polymyxin B controls in in vitro experiments

To minimize these issues, validate each new lot before use in critical experiments, avoid freeze-thaw cycles by preparing single-use aliquots, and include appropriate positive and negative controls.

How can I differentiate between IL-17E and other IL-17 family members in complex biological samples?

Distinguishing IL-17E from other IL-17 family members requires specific approaches:

• Antibody selection for ELISA/Western blotting:

  • Use antibodies validated for lack of cross-reactivity with other IL-17 family members

  • When possible, employ sandwich ELISA formats where both capture and detection antibodies recognize different epitopes specific to IL-17E

  • Validate specificity using recombinant proteins for all family members as controls

• RT-PCR primer design:

  • Design primers targeting regions with minimal sequence homology between family members

  • Validate specificity using plasmids containing each IL-17 family member

  • Consider using digital PCR for absolute quantification and improved specificity

• Biological validation:

  • IL-17E predominantly induces Th2 cytokines (IL-4, IL-5, IL-13), while IL-17A/F primarily induces neutrophil-attracting chemokines and G-CSF

  • Confirming downstream signature cytokine patterns can help validate which IL-17 family member is dominant in your sample

• Receptor blocking studies:

  • IL-17E specifically requires IL-17RB, while IL-17A/F signal through IL-17RA/RC

  • Using receptor-specific blocking antibodies can help attribute biological effects to specific family members

• Mass spectrometry approaches:

  • For definitive identification, targeted mass spectrometry can differentiate between family members based on specific peptide sequences

  • This approach requires specialized equipment but provides the highest specificity

When reporting IL-17 family member data, clearly specify which detection methods were used and include validation data demonstrating specificity.

What is known about the role of IL-17E in neurodevelopmental disorders using mouse models?

Research on IL-17E in neurodevelopmental disorders is an emerging field with several key findings:

• Maternal immune activation (MIA) models: Studies using poly(I:C) (20 mg/kg) or LPS (0.05 mg/kg) administered at embryonic day 12.5 have demonstrated alterations in IL-17 levels, potentially including IL-17E .

• Age-dependent alterations: One study found decreased IL-17 levels at postnatal day 30 in cerebellar lysates from MIA mice, suggesting that IL-17 dysregulation may be age-dependent .

• Tissue-specific changes: IL-17 alterations have been observed in multiple tissues including:

  • Cerebellar lysates

  • Microglia

  • Serum

  • Placenta

  • Maternal tissues

• Relationship to autism-like behaviors: Several studies have demonstrated correlations between altered IL-17 levels and autism-like behaviors in mouse models, suggesting a potential mechanistic link .

• Sex differences: Some studies report sex-specific alterations in IL-17 levels and responses, suggesting that sex may be an important variable in IL-17E-related neurodevelopmental effects .

Future research should focus on distinguishing specific roles of different IL-17 family members, including IL-17E, in neurodevelopmental processes, as most current studies have focused on IL-17A or have not differentiated between family members.

How can IL-17E be targeted therapeutically in mouse models of inflammatory disease?

Multiple approaches have been developed to target IL-17E in mouse models of inflammatory disease:

• Neutralizing antibodies:

  • Anti-IL-17E monoclonal antibodies can block IL-17E signaling in vivo

  • Typical dosing ranges from 50-200 μg per mouse, administered every 2-3 days

  • Consider isotype control antibodies to account for potential Fc-mediated effects

• Receptor antagonists:

  • Soluble IL-17RB-Fc fusion proteins can act as decoy receptors

  • Small molecule inhibitors targeting the IL-17E/IL-17RB interaction are in development

  • Dual blockade of IL-17RA (used by multiple family members) and IL-17RB (specific for IL-17E) may be necessary for complete inhibition

• Genetic approaches:

  • Conditional knockout systems using Cre-loxP allow tissue-specific IL-17E deletion

  • CRISPR/Cas9-mediated gene editing can be used for targeted mutations

  • siRNA or antisense oligonucleotides can provide transient knockdown in specific tissues

• Downstream pathway inhibition:

  • Targeting Act1, a critical signaling mediator downstream of IL-17RB

  • STAT6 inhibitors may block IL-17E-induced Th2 responses

  • Dual inhibition of IL-17E and IL-13 has shown synergistic effects in allergic models

• Timing considerations:

  • Early intervention during sensitization versus later during challenge phase

  • Preventive versus therapeutic administration

  • Duration of treatment and potential for rebound effects

Swaidani et al. demonstrated that epithelial-derived Act1 is critical for IL-17E-mediated pulmonary inflammation, suggesting that targeting this pathway specifically in epithelial cells might provide therapeutic benefit with fewer off-target effects .

What is the relationship between IL-17E and other cytokines in mouse models of inflammatory disease?

IL-17E functions within a complex cytokine network with multiple interactions:

• Relationship with other IL-17 family members:

  • IL-17E promotes Th2 responses, while IL-17A/F promote Th17 responses

  • In some models, these cytokines counterregulate each other

  • In other contexts, they may act synergistically to amplify inflammation through different mechanisms

• IL-17E and epithelial alarmins:

  • IL-33 and TSLP often work in concert with IL-17E

  • These three epithelial-derived cytokines form a triad promoting type 2 inflammation

  • Combined blockade may be more effective than targeting IL-17E alone

• IL-17E and downstream Th2 cytokines:

  • IL-17E induces production of IL-4, IL-5, and IL-13

  • These downstream cytokines mediate many of the effects attributed to IL-17E

  • Feedback loops may exist where Th2 cytokines further enhance IL-17E production

• IL-17E and innate lymphoid cells (ILCs):

  • IL-17E is a potent activator of ILC2s

  • ILC2-derived cytokines may amplify or modify IL-17E-initiated responses

• IL-17E in the context of interferon responses:

  • Type I and II interferons often suppress IL-17E-mediated responses

  • This relationship is important in viral/bacterial co-infection models

  • IL-17E can induce increased gene expression of IFN-γ in several tissues

Studies using transgenic mice with forced expression of murine IL-17E have revealed both Th2-biased responses and increased expression of IFN-γ and TNF-α, suggesting complex interactions that may be context-dependent .

What are the most promising future research directions for IL-17E in mouse models?

Several emerging areas present exciting opportunities for IL-17E research:

• Single-cell approaches: Single-cell RNA sequencing and CyTOF analyses will help identify specific cellular sources and targets of IL-17E with unprecedented resolution.

• Tissue-specific functions: Exploring IL-17E roles beyond traditional allergic and parasitic immunity, including:

  • Neuroinflammation and neurodevelopment

  • Metabolic inflammation

  • Tissue repair and fibrosis

  • Cancer immunology

• Receptor complex dynamics: Investigating how the assembly and signaling of the IL-17RB/IL-17RA complex is regulated in different cell types and disease states.

• Microbiome interactions: Examining how the microbiome influences IL-17E production and how IL-17E shapes microbiome composition in various barrier tissues.

• Therapeutic applications: Developing more specific approaches to target the IL-17E pathway for treating allergic and inflammatory diseases, potentially including:

  • Receptor-selective inhibitors

  • Cell-type specific delivery systems

  • Combination therapies targeting multiple epithelial alarmins

These research directions will benefit from advances in genetic engineering, imaging technologies, and computational approaches to analyze complex cytokine networks.

What standardized protocols should researchers follow when reporting IL-17E data from mouse studies?

To improve reproducibility and comparability across studies, researchers should follow these standardized reporting guidelines:

Following these guidelines will enhance the value of IL-17E research and facilitate translation of findings from mouse models to human applications.