Recombinant Mouse Interleukin-13 protein (Il13), partial (Active)
Description
Functional Mechanisms
IL-13 exerts its effects through a receptor complex comprising IL-4Rα, IL-13Rα1, and IL-13Rα2 subunits . Key functional attributes include:
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Immune Modulation:
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Signaling Pathways:
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Cross-Reactivity: Binds human IL-13 receptors, enabling translational studies .
3.1. In Vitro Studies
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Cell Proliferation Assays: ED<sub>50</sub> of 0.3–3 ng/mL in TF-1 erythroleukemic cell lines .
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Cytokine Profiling: Used to study Th1/Th2 polarization and allergic responses .
3.2. Disease Models
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Allergic Inflammation: Critical in asthma and atopy models .
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Intestinal Ischemia/Reperfusion (I/R) Injury:
Comparative Bioactivity Data
| Parameter | Value | Source |
|---|---|---|
| Bioactivity (TF-1 cells) | ED<sub>50</sub>: 0.3–3 ng/mL | |
| Half-Life (Serum) | Short (endogenous production sustained) | |
| Receptor Affinity | High for IL-13Rα2 (decoy receptor) |
Key Research Findings
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Cytoprotection in I/R Injury: rIL-13 administration reduced intestinal MPO activity (marker of neutrophil infiltration) by 40% and suppressed IL-2/IFN-γ mRNA expression while elevating IL-4/IL-13 levels .
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Therapeutic Potential: IL-13Rα2 acts as a decoy receptor, modulating extracellular IL-13 bioavailability in glioma and asthma models .
Product Specs
Target Background
- S1PR2 facilitates lung fibrosis through mechanisms involving augmentation of IL-13 expression and its signaling in BALF cells. PMID: 29782549
- Combined blockade of the IL-13 and IL-33 pathways leads to a greater inhibition of type 2 inflammation compared to inhibition of either pathway alone. PMID: 27697499
- Both pre- and post-transcriptional processes may be involved in the AR modulation of ILC2 IL-5 and IL-13 production. PMID: 28982732
- The endothelial barrier was preserved in respiratory epithelium isolated from MCU-/- mice after exposure to IL-13. In the ovalbumin-model of allergic airway disease, MCU deficiency resulted in decreased apoptosis within the large airway epithelial cells. Concordantly, expression of the tight junction protein ZO-1 was preserved, indicative of maintenance of epithelial barrier function. PMID: 29225050
- Controls the rate of epithelial cell movement through the epidermis and acts as a molecular bridge between intraepithelial lymphocytes and epithelial cells. PMID: 27357235
- Results demonstrate that IL-13 is a major regulator of radiation-induced lung injury and suggests that strategies focusing on IL-13 may be useful in screening for timely delivery of anti-IL-13 therapeutics. PMID: 28004808
- Using a mouse model of Th2-mediated inflammation induced by OVA-allergen, this study observed elevated lung amounts of IL-13 and IL-4 accompanied by increased autophagosome levels, determined by LC3BII protein levels and immunostaining. PMID: 28982074
- Metaplasia induction and macrophage polarisation after parietal cell loss is coordinated through a cytokine signaling network of IL-33 and IL-13, linking a combined response to injury by both intrinsic mucosal mechanisms and infiltrating M2 macrophages. PMID: 28196875
- IL-13 is able to signal independent of the IL-4Ra chain in AD (atopic dermatitis), which may lead to the identification of molecular pathways downstream of IL-13 signaling that could be targeted in future therapies for AD. PMID: 26896776
- The presence of interleukin-13 (IL-13), which can convert inflammatory into Ym1+ alternatively activated macrophages, at (acinar-to-ductal metaplasia [ADM]), which then gives rise to pancreatic intraepithelial neoplasia lesions, is reported. PMID: 28514653
- Data indicate that interleukin-33 (IL-33)-induced Interleukin-13 (IL-13) production by type-2 helper T cells (Th2 cells) is dependent on epidermal growth factor receptor (EGFR) expression. PMID: 29045902
- This study shows that environmental IL-13 plays a role in conditioning early thymic progenitors lineage choice, which would impact T cell development. PMID: 28893952
- IL-4 and IL-13 are required to effectively polarize macrophages/dendritic cells to an M2a phenotype and to promote recovery from acute kidney injury. PMID: 27745702
- This study shows that ST2 regulates early IL-13 production in fungus-induced allergic airway inflammation. PMID: 26555705
- These observations suggest that IL-4 and IL-13 likely operate through the Heteroreceptor and influence Th17 cells to convert to Th1 cells and to acquire increased sensitivity to suppression, leading to control of immune-mediated CNS inflammation. PMID: 28801358
- MIF-deficient mice have reduced Nippostrongylus brasiliensis burden and mounted an enhanced type 2 immune response, including increased Gata3 expression and IL-13 production in the mesenteric lymph nodes. PMID: 27049059
- Findings suggest that a leukotriene B4 receptor-2-linked cascade plays a pivotal role in LPS/TLR4 signaling for IL-13 synthesis in mast cells, thereby potentially exacerbating allergic response. PMID: 28600286
- Study found IL-13 to be critically involved in the development of chemical-induced asthma, as shown by using IL-13 KO mice, and more specifically in the effector phase as confirmed by anti- IL-13 antibody treatment. PMID: 28704401
- These studies show that fibrosis, steatosis, cholestasis, and ductular reaction are simultaneously controlled but distinctly regulated by interleukin-13 signaling. PMID: 27421703
- Our data support that impaired clearance of inhaled allergens triggering IL-13 production by multiple cell types in the airways plays an important role in the pathogenesis of type 2 airway inflammation and suggests therapeutic improvement of mucociliary clearance as a novel treatment strategy for children with allergen-induced asthma. PMID: 27865862
- This study shows that wild-type mice develop an eosinophilic Th2 airway disease in response to Alternaria alternata exposure, whereas IL-13-deficient mice exhibit a primarily neutrophilic response. PMID: 27815425
- This study shows that IL-17A contributes to asthma pathophysiology by increasing the capacity of IL-13 to activate intracellular signaling pathways, such as STAT6 activation. PMID: 27417023
- RCM-1 reduced IL-13 and STAT6 (signal transducer and activator of transcription 6) signaling and prevented the expression of the STAT6 target genes Spdef and Foxa3, which are key transcriptional regulators of goblet cell differentiation. PMID: 28420758
- IL-13 suppressed both the activation-induced apoptosis of CD4(+) T cells and the expression of p53 and FasL. PMID: 26189367
- We clearly show that miR-155 has a previously unknown direct regulatory role in the ILC2 subset that affects IL-33 receptor expression, IL-33 responsiveness, and IL-13 production as well as proliferation capability, possibly due to defects in GATA-3 function. PMID: 27492144
- The presented data substantiate the hypothesis that claudin-18 is a central barrier-forming component of tight junctions and show that IL-13 downregulates claudin-18. These data also suggest that the loss of claudin-18 is associated with increased sensitization to aeroantigens and airway responsiveness. PMID: 27215490
- Studies in colonic T84 cell monolayers revealed that barrier disruption by the colitis-associated Th2-type cytokines, IL-4 and IL-13, down-regulates matriptase as well as prostasin through phosphorylation of the transcriptional regulator STAT6. PMID: 28490634
- These data demonstrate that multiple pathogenic strains of RSV induce IL-13-producing group 2 innate lymphoid cell proliferation and activation through a TSLP-dependent mechanism in a murine model and suggest the potential therapeutic targeting of TSLP during severe RSV infection. PMID: 27156176
- The soluble antigen from A. cantonensis could promote the Chil3 expression in macrophage and microglial cell lines induced by interleukin-13. PMID: 27256220
- The reduction in fibrosis observed when IL-13 signaling is suppressed is not dependent on increased IFN-gamma activity. Instead, by reducing compensatory increases in type 1-associated inflammation, therapeutic strategies that block IFN-gamma and IL-13 activity simultaneously can confer greater protection from progressive fibrosis than IL-13 blockade alone. PMID: 27125685
- The IL-23/IL-17 axis plays a critical role in the immunopathology of hepatic amebiasis. IL-13 secreted by CD11b(+)Ly6C(lo) monocytes may be associated with recovery from liver damage. PMID: 26809113
- PLD1 activation enhanced binding of ROCK1 to ATF-2 and leads to increased expression of IL-13. PMID: 26335962
- Macrophages are critical to the maintenance of IL-13-dependent lung inflammation and fibrosis. PMID: 25921340
- IL-25 and CD4(+) TH2 cells enhance type 2 innate lymphoid cell-derived IL-13 production, which promotes IgE-mediated experimental food allergy. PMID: 26560039
- Placenta growth factor augments airway hyperresponsiveness via leukotrienes and IL-13. PMID: 26690703
- Natural helper cells contribute to pulmonary eosinophilia by producing IL-13 via IL-33/ST2 pathway in a murine model of respiratory syncytial virus infection. PMID: 26044350
- Review of IL-4 and IL-13 mast cell immunity and detail of the differences that exist between mouse and human mast cell responses to IL-4 and IL-13 [review]. PMID: 26088754
- Data (including data from studies in knockout/transgenic mice) suggest T cell-derived IL4/IL13 are required for immunologic memory and IgE response to helminth Nippostrongylus brasiliensis but are not required for expansion/proliferation of B cells. PMID: 26523376
- Curcumin up-regulates mRNA and protein levels of IL-4 and IL-13. PMID: 25944087
- These data indicate that distal airways might be less sensitive to IL-13-induced GC metaplasia and mucus production through lower expression of IL-13Ralpha1 and attenuated activation of downstream signaling. PMID: 25772331
- IL-13 induces miR-142-5p and downregulates miR-130a-3p in macrophages, regulating macrophage profibrogenic gene expression in chronic inflammation. PMID: 26436920
- IL-4 and IL-13 have a critical role in innate immune cells for protective immunity against gastrointestinal helminths. PMID: 25336167
- These data demonstrate that dysregulated IL-25 expression contributes to lipid accumulation, whereas exogenous IL-25 protects against hepatic steatosis through IL-13 activation of STAT6. PMID: 26423151
- TH2 cells and their cytokines IL-4 and IL-13 regulate formation and function of lymphatic vessels. PMID: 25648335
- Mice with experimental Schistosoma-induced pulmonary hypertension (PH) had evidence of increased IL-4 and IL-13 signaling. IL-4(-/-)IL-13(-/-) mice, but not single knockout IL-4(-/-) or IL-13(-/-) mice, were protected from Schistosoma-induced PH. PMID: 26192556
- Regulates the expression of IL-17A in HIV-specific CD8 T cells following immunizations. PMID: 25493691
- These data establish for the first time a molecular mechanism by which Mac-1 regulates the signaling activity of IL-13 in macrophages. PMID: 26160172
- Acidic pH augments Fc-epsilon-RI-mediated production of IL-6 and IL-13 in mast cells. PMID: 26196745
- Conjunctival goblet cells are IL-13 responsive cells that produce factors known to maintain epithelial barrier, stimulate mucin production, and modulate immune response in nonocular mucosa when treated with IL-13. PMID: 26132778
- Enhanced IL-13 production by T cells can play a causative role in the exocrinopathy observed in Id3 knockout mice. PMID: 25010390
Q&A
What is the molecular structure of mouse IL-13?
Mouse IL-13 is a monomeric cytokine with a molecular weight of approximately 11.0 kDa as determined by SEC-MALS analysis. It contains two internal disulfide bonds that contribute to its bundled four alpha-helix configuration . When resolved by SDS-PAGE under reducing conditions, recombinant mouse IL-13 appears as a single band at approximately 9 kDa . The protein can exist in multiple glycosylated forms with molecular weights ranging from 11.3 to 15 kDa .
How does mouse IL-13 compare structurally to IL-13 from other species?
Mature mouse IL-13 shares 57% amino acid sequence identity with human IL-13, 75% with rat IL-13, and 58% with rhesus IL-13 . Despite this relatively low homology, mouse IL-13 exhibits cross-species activity between human, mouse, and rat systems . This evolutionary conservation reflects the fundamental importance of IL-13 in immune regulation across mammalian species.
What are the primary biological functions of mouse IL-13?
Mouse IL-13 is a pleiotropic Th2 cytokine with diverse effects on multiple cell types:
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In macrophages: Suppresses production of proinflammatory cytokines (IL-1β, IL-6, TNF, IL-12), induces morphological changes (flattening and development of processes), and increases MHC class II expression
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In B cells: Enhances antibody production by increasing cell survival, stimulates production of IgM and various IgG subtypes, and has been shown to directly stimulate mouse B cells in vivo and in vitro
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In fibroblasts and endothelial cells: Upregulates IL-6 while downregulating IL-1 and TNF-alpha production
What are the optimal storage and handling conditions for recombinant mouse IL-13?
For maximum retention of biological activity, recombinant mouse IL-13 should be aliquoted upon initial thawing and stored at -80°C . For working solutions, prepare stock dilutions in sterile neutral buffer containing carrier protein (0.5-10 mg/ml of bovine serum albumin) . The concentration should not fall below 5 μg/ml for long-term storage to prevent activity loss . Repeated freeze-thaw cycles should be avoided as they can compromise protein integrity and biological function.
How can the bioactivity of recombinant mouse IL-13 be quantitatively assessed?
The bioactivity of recombinant mouse IL-13 can be assessed through several functional assays:
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TF-1 cell proliferation assay: Recombinant mouse IL-13 stimulates proliferation of the TF-1 human erythroleukemic cell line with an ED50 of 0.75-3 ng/mL
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B cell antibody production: IL-13 enhances production of IgM and various IgG isotypes in anti-CD40-stimulated B cells
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Macrophage phenotype assay: Monitor morphological changes and MHC class II expression increases in mouse macrophages
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Cytokine modulation assay: Measure the inhibition of proinflammatory cytokine production in macrophages or other relevant cell types
What experimental approaches can be used to study IL-13 functions in vivo?
Recombinant mouse IL-13 can be administered via osmotic pump during immunization protocols to assess its effects on immune responses . In BALB/c mice immunized with chicken RBCs, IL-13 treatment significantly enhanced plasma levels of total IgG1, IgG2a, and IgG2b as well as antigen-specific immunoglobulin levels . This approach allows researchers to examine the effects of sustained IL-13 exposure on various immune parameters in a physiologically relevant context.
What comprises the mouse IL-13 receptor complex?
The mouse IL-13 receptor system consists of several components:
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IL-13Rα1: A low-affinity IL-13 binding chain involved in signal transduction
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IL-13Rα2: A high-affinity IL-13 binding chain (Kd of 0.5-1.2 nM) that maps to the X chromosome
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IL-4Rα: A component shared between IL-13 and IL-4 receptor complexes, explaining the overlapping functions between these cytokines
These receptor components interact in complex ways to mediate IL-13 responses across different cell types and physiological contexts.
How do IL-13Rα1 and IL-13Rα2 differ functionally?
IL-13Rα1 and IL-13Rα2 serve distinct biological functions:
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IL-13Rα1: When expressed in Ba/F3 cells, results in a sensitive proliferative response to IL-13, indicating its primary role in signal transduction
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IL-13Rα2: Binds IL-13 with higher affinity than IL-13Rα1 but does not induce proliferation in response to IL-13 . Cells transfected with IL-13Rα2 express approximately 5000 molecules per cell and bind IL-13 with a Kd of 0.5-1.2 nM
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Neutralization capacity: IL-13Rα2.Fc is approximately 100-fold more effective than IL-13Rα1.Fc at neutralizing IL-13 in vitro, consistent with its higher binding affinity
These differences suggest that IL-13Rα2 may function primarily as a regulatory "decoy" receptor to modulate IL-13 signaling.
What is the relationship between IL-13 receptor expression and cellular responsiveness?
Cellular responsiveness to IL-13 correlates strongly with receptor expression patterns. In squamous cell carcinoma of the head and neck (SCCHN) cell lines, heterogeneity in IL-13 receptor expression has been observed . While all cell lines expressed IL-13Rα1 and IL-4Rα chains equally, only 50% expressed IL-13Rα2, with 19% showing high expression . High IL-13Rα2 expression correlates with increased density of IL-13 receptors as demonstrated by receptor binding studies . This heterogeneity in receptor expression creates significant variations in cellular responsiveness to IL-13 and has implications for both normal physiology and pathological conditions.
How can the IL-13/IL-4 signaling overlap be experimentally distinguished?
Given the shared receptor components and overlapping functions of IL-13 and IL-4, researchers can differentiate their effects through several approaches:
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Specific neutralizing antibodies against each cytokine
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Receptor-specific blocking antibodies (anti-IL-4Rα, anti-IL-13Rα1, anti-IL-13Rα2)
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Comparative analysis of cellular responses that differ between IL-13 and IL-4 (e.g., IL-13 enhances B cell antibody production primarily by increasing survival, while IL-4 increases both survival and proliferation)
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Unlike IL-4, IL-13 does not increase CD23 expression or B cell proliferation as measured by dilution of intracellular fluorescence labels, providing a functional distinction between these cytokines
What are the implications of IL-13Rα2 in targeted therapeutic approaches?
The high expression of IL-13Rα2 in certain cancer cell lines has implications for targeted therapeutic strategies . Studies with chimeric proteins composed of IL-13 and mutated forms of Pseudomonas exotoxin (IL-13-PE38 or IL-13-PE38QQR) found that these fusion toxins were highly cytotoxic to IL-13Rα2-positive cells, while IL-13Rα2-negative cell lines showed low or no sensitivity . Transient transfection of IL-13Rα2 in previously negative cell lines significantly sensitized them to IL-13 toxin compared to mock-transfected controls . This differential expression pattern provides a potential avenue for targeted therapeutic interventions in cancer and inflammatory disorders.
How does mouse IL-13 specifically impact B cell function?
Although earlier studies suggested mouse B cells were unresponsive to IL-13, more recent research demonstrates that IL-13 directly stimulates mouse B cells, causing extended survival and enhancing antibody production . In anti-CD40-stimulated sIgD+ mouse B cells, IL-13 increases production of IgM and to a lesser extent IgG1, IgG2a, IgG2b, and IgG3 . This stimulation occurs directly rather than indirectly via contaminating cells, as IL-13 increased both total and antibody-secreting B cell numbers even in highly purified B cell populations (>99.5% pure) . Importantly, this effect is mechanistically distinct from IL-4, as IL-13 enhances antibody production primarily through improving B cell survival rather than increasing proliferation or inducing class switching .
What quality control parameters should be evaluated for recombinant mouse IL-13?
Critical quality control parameters for recombinant mouse IL-13 include:
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Purity: Should be ≥95% as determined by SDS-PAGE and absorbance assay based on the Beers-Lambert law
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Endotoxin levels: Should be ≤0.1 ng per μg of mouse IL-13, as measured by chromogenic LAL assay
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Biological activity: Verify using established bioassays such as TF-1 cell proliferation
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Protein concentration: Accurately determine using appropriate protein quantification methods
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Glycosylation status: Multiple glycosylated forms ranging from 11.3 to 15 kDa may be present and should be characterized
What factors might affect experimental outcomes when using recombinant mouse IL-13?
Several factors can influence experimental results when working with recombinant mouse IL-13:
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Carrier protein effects: Pre-screen carrier proteins for possible interference in experimental systems
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Storage conditions: Improper storage can lead to activity loss
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Target cell receptor expression: Heterogeneity in receptor expression among cell lines or primary cells can significantly impact responsiveness
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Presence of soluble receptors: Endogenous soluble receptors in biological samples may neutralize added IL-13
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Cross-species considerations: Despite cross-species activity, efficacy may vary between species systems
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Experimental timing: The kinetics of IL-13 responses may vary depending on the biological process being measured
