IL13Rα2­ and EGFR­targeted pseudomonas exotoxin potentiates the TRAIL­mediated death of GBM cells.

Glioblastomas (GBMs) are refractory to current treatments and novel therapeutic approaches need to be explored. Pro­apoptotic tumor necrosis factor­related apoptosis­inducing ligand (TRAIL) is tumor­specific and has been shown to induce apoptosis and subsequently kill GBM cells. However, approximately 50% of GBM cells are resistant to TRAIL and a combination of TRAIL with other therapeutics is necessary to induce mechanism­based cell death in TRAIL­resistant GBMs. The present study examined the ability of the tumor cell surface receptor, interleukin (IL)­13 receptor α2 (IL13Rα2)­ and epidermal growth factor receptor (EGFR)­targeted pseudomonas exotoxin (PE) to sensitize TRAIL­resistant GBM cells and assessed the dual effects of interleukin 13­PE (IL13­PE) or EGFR nanobody­PE (ENb­PE) and TRAIL for the treatment of a broad range of brain tumors with a distinct TRAIL therapeutic response. Receptor targeted toxins upregulated TRAIL death receptors (DR4 and DR5) and suppressed the expression of anti­apoptotic FLICE­inhibitory protein (FLIP) and X­linked inhibitor of apoptosis protein (XIAP). This also led to the induction of the cleavage of caspase­8 and caspase­9 and resulted in the sensitization of highly resistant established GBM and patient­derived GBM stem cell (GSC) lines to TRAIL­mediated apoptosis. These findings provide a mechanism­based strategy that may provide options for the cell­mediated delivery of bi­functional therapeutics to target a wide spectrum of TRAIL­resistant GBMs.

A new pyrimidine alkaloid from the roots of Tadehagi triquetrum (L.) H.Ohashi.

Tadehagi triquetrum (L.) H.Ohashi, also known as Desmodium triquetrum (Fabaceae) is the most important plant in the herbal remedies. The present study focus on the isolation, in-silico and in-vitro studies of the two alkaloids C1 (5-(4-[(methylcarbamoyl) amino]-2-oxopyrimidin-1(2H)-yl) tetrahydrofuran-2-yl) methyl methyl carbamate is novel alkaloid and C2 13-Docosenamide is a known alkaloid. The chemical structures of compounds have been elucidated based on comprehensive techniques like GCMS, IR and NMR. In order to know the molecular mechanisms for the two compounds, in silico molecular docking study has been performed. Both compounds have shown perfect binding affinity to the enzymes TNF α, IL-4, IL-13 and 5 LOX Enzyme. The compounds also exhibited comparable G-scores and Glide energy values in comparison with the standard dexamethasone. In addition both the compounds have been tested for in vitro antioxidant assay by using ABTS and DPPH method and the results were compared with standard ascorbic acid.

Development and characterization of monoclonal antibodies specific for chicken interleukin-13 and their neutralizing effects in chicken primary monocytes.

Compared with mammals, the functionality of chicken cytokines is not well understood because of the unavailability of immune reagents. Mammalian interleukin (IL)-13 is an important Th2 type cytokine with well-known biological functions through its 2 receptors, IL-13 receptor (IL-13R)-α1 and IL-13Rα2. In the present study, we developed mouse monoclonal antibodies (mAb) against chIL-13 and further investigated their specificity in detecting endogenously produced chIL-13. Upon characterization of mAb using indirect ELISA and Western blot, the capture ELISA was developed for detecting chIL-13. Neutralizing effects were tested by measuring nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in primary chicken monocytes stimulated with chIL-13, lipopolysaccharide (LPS), chIL-13+LPS, or chIL-13+LPS+mAb. In addition, gene expression of chIL-13Rα1, chIL-13Rα2, and TGF-ß1 was tested in chicken monocytes treated with chIL-13 or chIL-13+mAb. Based on indirect ELISA, 5 mAb that detected recombinant chIL-13 were identified, and all of them specifically detected recombinant chIL-13 protein by Western blotting. An optimal signal was obtained with 2 mAb (#9B11 and #10A2) in a pairing assay, and these 2 mAb were used in a capture assay. A neutralization assay further revealed that chIL-13 reduced LPS-stimulated NO production and iNOS expression in monocytes and macrophage cells, and the 2 mAb (#9B11 and #10A2) abrogated these effects. In addition, chIL-13-induced expressions of chIL-13Rα2 and TGF-ß1 were neutralized by the 2 mAb. In summary, the present study showed that chIL-13 may be involved in the alternative activation of primary monocytes in chickens and that chIL-13 signaling may be regulated through chIL-13Rα2 binding and TGF-ß1 secretion. Importantly, the newly developed anti-chIL-13 mAb will serve as valuable immune reagents for future studies on the biological activity of chIL-13 and its receptors.

Design and characterization of Zweimab and Doppelmab, high affinity dual antagonistic anti-TSLP/IL13 bispecific antibodies.

Patients with severe Th2 type asthma often have a steroid resistant phenotype and are prone to acute exacerbations. Current novel therapies have only marginal therapeutic effects. One of the hypotheses for lack of major efficacy in most patients is targeting only one redundant pathway leaving others active. Hence, we have designed and developed novel highly potent bispecific anti-TSLP/IL13 antibodies called Zweimabs (monovalent bispecific) and Doppelmabs (bivalent bispecific) that concurrently inhibits the signaling by these two cytokines.

Docking analysis and the possibility of prediction efficacy for an anti-IL-13 biopharmaceutical treatment with tralokinumab and lebrikizumab for bronchial asthma.

Interleukin-13 (IL-13) is associated with allergic airway inflammation and airway remodeling. Our group found a variant with a single nucleotide polymorphism in the IL13 gene at position +2044G>A (rs20541) that was expected to result in the non-conservative replacement of a positively charged arginine (R) with a neutral glutamine (Q) at position 144. IL-13Q144 was associated with augmented allergic airway inflammation and bronchial asthma remodeling. There is some indication that anti-IL-13 monoclonal antibodies can demonstrate a positive effect on the clinical course of refractory asthmatic patients. To date, the binding stability of these agents for IL-13Q144 is unknown. The objective of this study was to investigate the prediction efficacy of the anti-IL-13 monoclonal antibodies tralokinumab and lebrikizumab in asthmatic patients with IL-13R144 and IL-13Q144. The three-dimensional (3-D) structure of tralokinumab was obtained from the Protein Data Bank (PDB ID: 5L6Y), and the complete 3-D structure of lebrikizumab was built through homology modeling. For the binding stability analysis, we performed and analyzed docking simulations of IL-13 with tralokinumab or lebrikizumab. The tralokinumab and lebrikizumab structures changed after binding to IL-13 to facilitate binding with IL-13Q144. The stability analysis with tralokinumab and lebrikizumab demonstrated that IL-13Q144 was more stable than IL-13R144 for both the Rosetta energy score and for the free energy of binding. IL-13Q144 might be a promising predictor of responsiveness to tralokinumab and lebrikizumab treatment for bronchial asthma.

Interleukin-13 conjugated quantum dots for identification of glioma initiating cells and their extracellular vesicles.

Cadmium selenide (CdSe) based quantum dots modified with polyethylene glycol and chemically linked to interleukin-13 (IL13) were prepared with the aim of identifying the high affinity receptor (IL13Rα2) which is expressed in glioma stem cells and exosomes secreted by these cancer stem cells. IL13 conjugated quantum dots (IL13QD) were thoroughly characterized for their physicochemical properties including particle size and surface morphology. Furthermore, the specific binding of the IL13QD to glioma cells and to glioma stem cells (GSC) was verified using a competitive binding study. The exosomes were isolated from the GSC conditioned medium and the expression of IL13Rα2 in the GSC and exosomes was verified. The binding property of IL13QD to the tumor associated exosomes was initially confirmed by transmission electron microscopy. The force of attraction between the quantum dots and U251 glioma cells and the exosomes was investigated by atomic force microscopy, which indicated a higher force of binding interaction between the IL13QD and IL13Rα2 expressing glioma cells and exosomes secreted by glioma stem cells. Flow cytometry of the IL13QD and exosomes from the culture media and cerebrospinal fluid (CSF) of patients with glioma tumors indicated a distinctly populated complex pattern different from that of non-targeted quantum dots and bovine serum albumin (BSA) conjugated quantum dots confirming specific binding potential of the IL13QD to the tumor associated exosomes. The results of this study demonstrate that IL13QD can serve as an ex vivo marker for glioma stem cells and exosomes that can inform diagnosis and prognosis of patients harboring malignant disease. STATEMENT OF SIGNIFICANCE: Functionalized quantum dots are flexible semiconductor nanomaterials which have an immense application in biomedical research. In particular, when they are functionalized with biomolecules like proteins or antibodies, they have the specialized ability to detect the expression of receptors and antigens in cells and tissues. In this study we designed a cytokine (interleukin-13) functionalized quantum dot to detect a cancer associated receptor expressed in cancer stem cells and the extracellular vesicles (exosomes) secreted by the cancer cells themselves. The binding pattern of these cytokine modified quantum dots to the cancer stem cells and exosomes alters the physical properties of the complex in the fixed and suspended form. This altered binding pattern can be monitored by a variety of techniques, including transmission electron microscopy, atomic force microscopy and flow cytometry, and subsequent characterization of this quantum dot binding profile provides useful data that can be utilized as a fingerprint to detect cancer disease progression. This type of functionalized quantum dot fingerprint is especially useful for invasive cancers including brain and other metastatic cancers and may allow for earlier detection of disease progression or recurrence, thus saving the lives of patients suffering from this devastating disease.

Detecting Chronic Post-Traumatic Osteomyelitis of Mouse Tibia via an IL-13Rα2 Targeted Metallofullerene Magnetic Resonance Imaging Probe.

Differential diagnosis of chronic post-traumatic osteomyelitis (CPO) from aseptic inflammation remains challenging, since both pathological processes share similar clinical symptoms. Here we utilized a novel targeted metallofullerene nanoparticle based magnetic resonance imaging (MRI) probe IL-13-TAMRA-Gd3N@C80(OH)30(CH2CH2COOH)20 to detect CPO in mouse tibia via overexpressed IL-13Rα2 receptors. The functionalized metallofullerene was characterized by X-ray photoelectron spectroscopy. Upon lipopolysaccharide (LPS) stimulation, macrophage Raw 264.7 cells showed elevated IL-13Rα2 expression via immunofluorescence staining and increased MRI probe binding via built-in TAMRA fluorescence imaging. Trauma was induced in both tibia of mice and bacteria soaked suture was inserted into the right tibia to initiate infection. During the acute phase (1.5 weeks), luminol-bioluminescence imaging revealed much higher myeloperoxidase activity in the infected tibia compared to the sham. In the chronic phase (4 weeks), X-ray radiography illustrated bone deformation in the infected tibia compared to the sham. With T1 weighted sequences, the probe clearly exhibited hyperintensity in the infection foci at both acute and chronic phases, which was not observed in the sham tibia. Histological analysis revealed severe bone structural destruction and massive inflammatory cell infiltration in the infected tibia. Immunohistochemistry confirmed abundant expression of IL-13Rα2 in the infection site. In summary, we developed a noninvasive imaging approach to detect and differentiate CPO from aseptic inflammation using a new IL-13Rα2 targeted metallofullerene MRI probe. In addition, for the first time, IL-13Rα2 was investigated as a unique biomarker in the context of osteomyelitis. Our data established a foundation for the translational application of this MRI probe in the clinical differentiation of CPO.

Interleukin-13 as an important cytokine: A review on its roles in some human diseases.

Interleukin-13 (IL-13) as a pleiotropic cytokine acts through the IL-13Ra1/IL-4Ra complex to induce activation responses which contribute to the inflammatory diseases. Genetic polymorphisms in IL-13 and its receptor components have been proved to be associated with higher disease prevalence rates. Animal models such as in IL-13 deficient mice and transgenic animals also have been confirmed the critical role of this cytokine in the immune responses, mostly by IL-13 neutralization and IL-13/IL-4 dual neutralization strategies. This review highlights IL-13 structure as well as its pivotal roles in the normal physiologic and pathologic states. It is followed by a section on the recent findings on IL-13 receptors and signalling mechanisms to briefly summarize its functions in the immune systems. IL-13 roles in the human diseases such as asthma, systematic sclerosis, and some inflammatory diseases are described concisely. Finally some of the ongoing therapeutic applications are presented to comprehensively review IL-13 mediator roles.

Instructive roles for cytokine-receptor binding parameters in determining signaling and functional potency.

Cytokines dimerize cell surface receptors to activate signaling and regulate many facets of the immune response. Many cytokines have pleiotropic effects, inducing a spectrum of redundant and distinct effects on different cell types. This pleiotropy has hampered cytokine-based therapies, and the high doses required for treatment often lead to off-target effects, highlighting the need for a more detailed understanding of the parameters controlling cytokine-induced signaling and bioactivities. Using the prototypical cytokine interleukin-13 (IL-13), we explored the interrelationships between receptor binding and a wide range of downstream cellular responses. We applied structure-based engineering to generate IL-13 variants that covered a spectrum of binding strengths for the receptor subunit IL-13Rα1. Engineered IL-13 variants representing a broad range of affinities for the receptor exhibited similar potencies in stimulating the phosphorylation of STAT6 (signal transducer and activator of transcription 6). Delays in the phosphorylation and nuclear translocation of STAT6 were only apparent for those IL-13 variants with markedly reduced affinities for the receptor. From these data, we developed a mechanistic model that quantitatively reproduced the kinetics of STAT6 phosphorylation for the entire spectrum of binding affinities. Receptor endocytosis played a key role in modulating STAT6 activation, whereas the lifetime of receptor-ligand complexes at the plasma membrane determined the potency of the variant for inducing more distal responses. This complex interrelationship between extracellular ligand binding and receptor function provides the foundation for new mechanism-based strategies that determine the optimal cytokine dose to enhance therapeutic efficacy.

A New Interleukin-13 Amino-Coated Gadolinium Metallofullerene Nanoparticle for Targeted MRI Detection of Glioblastoma Tumor Cells.

The development of new nanoparticles as next-generation diagnostic and therapeutic ("theranostic") drug platforms is an active area of both chemistry and cancer research. Although numerous gadolinium (Gd) containing metallofullerenes as diagnostic magnetic resonance imaging (MRI) contrast agents have been reported, the metallofullerene cage surface, in most cases, consists of negatively charged carboxyl or hydroxyl groups that limit attractive forces with the cellular surface. It has been reported that nanoparticles with a positive charge will bind more efficiently to negatively charged phospholipid bilayer cellular surfaces, and will more readily undergo endocytosis. In this paper, we report the preparation of a new functionalized trimetallic nitride template endohedral metallofullerene (TNT EMF), Gd3N@C80(OH)x(NH2)y, with a cage surface bearing positively charged amino groups (-NH3(+)) and directly compare it with a similar carboxyl and hydroxyl functionalized derivative. This new nanoparticle was characterized by X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and infrared spectroscopy. It exhibits excellent (1)H MR relaxivity. Previous studies have clearly demonstrated that the cytokine interleukin-13 (IL-13) effectively targets glioblastoma multiforme (GBM) cells, which are known to overexpress IL-13Rα2. We also report that this amino-coated Gd-nanoplatform, when subsequently conjugated with interleukin-13 peptide IL-13-Gd3N@C80(OH)x(NH2)y, exhibits enhanced targeting of U-251 GBM cell lines and can be effectively delivered intravenously in an orthotopic GBM mouse model.

Semisynthesis of a post-translationally modified protein by using chemical cleavage and activation of an expressed fusion polypeptide.

Herein, we describe a new semisynthetic strategy of a post-translationally modified protein in which the middle region is glycosylated. We designed a single-plasmid coding for a fusion polypeptide, which can provide both an N-terminal α-thioester and a C-terminal cysteine peptide of a target glycoprotein by using chemical-cleavage and activation methods. The use of these resultant peptide derivatives resulted in the successful synthesis of N-glycosylated-interleukin 13.

In vitro and in vivo intracellular distribution and anti-glioblastoma effects of docetaxel-loaded nanoparticles functioned with IL-13 peptide.

An active targeting delivery system helps increase intracellular drug delivery, which is promising for the treatment of glioblastoma. Interleukin 13 (IL-13) peptide which was derived from IL-13 protein could specially bind with IL-13Rα2, a receptor highly expressed on glioblastoma cells but not on normal brain cells, suggesting IL-13 peptide is an optional ligand for glioblastoma targeted therapy. In this contribution, IL-13 peptide was functionalized to nanoparticles (ILNP) to form a glioblastoma targeted drug delivery system where docetaxel was used as a model drug. The cellular uptake and intracellular delivery of ILNP indicated that IL-13 peptide facilitated cellular uptake of nanoparticles and Golgi apparatus was involved in the sorting and trafficking of ILNP rather than NP in U87 cells. Transmission electron microscopy observation revealed that ILNP mainly distributed into endosomes, cytoplasm and Golgi apparatus. In vitro apoptosis assay indicated docetaxel-loaded ILNP could induce polymerization of microtubules and produce the highest early and late apoptosis of U87 cells. Growth inhibition results of tumor spheroids demonstrated ILNP displayed the best growth inhibition of tumor spheroids. In vivo imaging suggested that ILNP accumulated significantly more in the glioma site than NP while more NP was distributed in liver, lung and spleen than ILNP. Transmission electron microscopy further demonstrated ILNP could distribute into different organelles of cells in glioma site. Thus, docetaxel loaded ILNP could induce the most apoptosis of glioma cells which was demonstrated by TUNEL. In conclusion, we presented a glioblastoma-targeting drug delivery system ILNP, which could increase the intracellular delivery of nanoparticles as well as precisely target to glioblastoma cells, and significantly increase the anti-proliferation and anti-spheroid growth effect.

A computational tool to predict the evolutionarily conserved protein-protein interaction hot-spot residues from the structure of the unbound protein.

Identifying hot-spot residues - residues that are critical to protein-protein binding - can help to elucidate a protein's function and assist in designing therapeutic molecules to target those residues. We present a novel computational tool, termed spatial-interaction-map (SIM), to predict the hot-spot residues of an evolutionarily conserved protein-protein interaction from the structure of an unbound protein alone. SIM can predict the protein hot-spot residues with an accuracy of 36-57%. Thus, the SIM tool can be used to predict the yet unknown hot-spot residues for many proteins for which the structure of the protein-protein complexes are not available, thereby providing a clue to their functions and an opportunity to design therapeutic molecules to target these proteins.

Role of periostin, FENO, IL-13, lebrikzumab, other IL-13 antagonist and dual IL-4/IL-13 antagonist in asthma.

INTRODUCTION: Asthma markedly diminishes quality of life due to limited activity, absences from work or school and hospitalizations. Patients with severe asthma which are not controlled despite taking effective therapy are most in need of new treatment approaches. IL-13 was demonstrated as 'central mediator of allergic asthma'. AREAS COVERED: IL-13 has been implicated in the pathogenesis of asthma, idiopathic pulmonary fibrosis and COPD. IL-13 levels in the sputum and bronchial biopsy samples remain elevated in severe asthma despite the use of inhaled and systemic corticosteroids. Thus, IL-13 is a mediator involved in corticosteroid resistance. Periostin enhances profibrotic TGF-ß signaling in subepithelial fibrosis associated with asthma. IL-13 induces bronchial epithelial cells to secrete periostin. Periostin may be a biomarker for Th2 induced airway inflammation. Lebrikizumab is a monoclonal antibody against IL-13. Lebrikizumab improved lung function in asthmatics who were symptomatic despite treatment with long acting beta agonist and inhaled corticosteroids and provided benefit in the treatment of severe uncontrolled asthma. EXPERT OPINION: Lebrikizumab block IL-13 signaling through the IL-13Rα1/IL-4Rα receptor. There was a larger reduction in FENO in the high periostin subgroup than in the low periostin subgroup (34.4 vs 4.3%). Serum CCL17, CCL13 and total IgE levels decreased in the lebrikizumab group.

Glioma-homing peptide with a cell-penetrating effect for targeting delivery with enhanced glioma localization, penetration and suppression of glioma growth.

Tumor-targeted delivery systems are useful in enhancing drug delivery and increasing anti-tumor effects. Cell-penetrating peptides have been widely used for this purpose but have been hampered by the poor selectivity between neoplastic and non-neoplastic cells. As a peptide derived from interleukin-13, interleukin-13 peptide (IL-13p) is specifically targeted to IL13Rα2, a tumor-restricted receptor. More interestingly, IL-13p possesses cell-penetrating properties that can specifically enhance the uptake by tumor cells compared with endothelial cells. Thus, we anchored IL-13p onto nanoparticles (ILNPs) for glioma-targeting delivery. The uptake of ILNPs by U87 cells was higher than that of unmodified nanoparticles (NPs). However, there was no significant difference in the uptake by human umbilical vein endothelial cells. In addition, free IL-13p could also enhance the uptake of both NPs and ILNPs by U87 cells. Anchoring with IL-13p could enhance the penetration of particles into the core of spheroids. In vivo, the fluorescence intensity of ILNPs in tumors was 2.96-fold higher than that of NPs. The modification with IL-13p also significantly improved the speed and rate of penetration from vessels to tumor cells. The enhanced tumor localization of ILNPs was mostly attributable to the elevated tumor cell internalization of ILNPs, whereas most NPs were colocalized with microvessels or macrophages. Correspondingly, docetaxel-loaded NPs effectively suppressed the growth of subcutaneous U87 tumors. The average tumor volume of the ILNP group was only 31.4% that of the control, which was significantly smaller than that of the docetaxel and NP groups. In conclusion, the modification of IL-13p selectively enhanced tumor cell uptake, improved the penetration effect of NPs and improved the glioma localization ability, which led to a better tumor-suppression effect.

Ligand modified nanoparticles increases cell uptake, alters endocytosis and elevates glioma distribution and internalization.

Nanoparticles (NPs) were widely used in drugs/probes delivery for improved disease diagnosis and/or treatment. Targeted delivery to cancer cells is a highly attractive application of NPs. However, few studies have been performed on the targeting mechanisms of these ligand-modified delivery systems. Additional studies are needed to understand the transport of nanoparticles in the cancer site, the interactions between nanoparticles and cancer cells, the intracellular trafficking of nanoparticles within the cancer cells and the subcellular destiny and potential toxicity. Interleukin 13 (IL-13) peptide can specifically bind IL-13Rα2, a receptor that is highly expressed on glioma cells but is expressed at low levels on other normal cells. It was shown that the nanoparticels modification with the IL-13 peptide could improve glioma treatment by selectively increasing cellular uptake, facilitating cell internalization, altering the uptake pathway and increasing glioma localization.

Association of IL-13 gene polymorphisms with airway hyperresponsiveness in a Japanese adult asthmatic population.

BACKGROUND: A single nucleotide polymorphism (SNP; rs20541) in the IL-13 gene has been recognized as a risk factor for asthma. This SNP causes Arg to Gln (Q) substitution at position 110 in the mature IL-13 protein. We have recently showed that FEV1 in asthmatics with the Q110 variant of IL-13 declined faster, and progressive airway remodeling was observed in these subjects (Wynn, 2003 [1]). However, the effects of the IL-13 variant on airway hyperresponsiveness (AHR) remain to be elucidated. We analyzed the relationship between SNP rs20541 in IL-13 and AHR in asthmatics. METHODS: We recruited 182 asthmatics who visited the asthma outpatient clinic at Iwate Medical University Hospital from 2006 to 2011. Subjects were genotyped for rs20541. Asthma severity, atopic status, age of asthma onset, serum IgE concentration, AHR, and pulmonary function were studied in these subjects. AHR was measured using the continuous methacholine inhalation method (Astograph; Chest; Tokyo, Japan). RESULTS: Genotyping of rs20541 revealed 26 A/A, 77 A/G, and 79 G/G patient genotypes. The D min (U) of the 3 genotypes was 1.17±0.300 in A/A, 1.99±0.35 in A/G, and 2.85±0.39 in G/G. The D min in the 3 genotypes was significantly different. Spirometric data revealed that % FEV1 and % FEF75 were significantly different among the 3 groups of IL-13 genotypes, whereas no significant differences were observed in therapeutic steps, atopic status, house dust mite sensitization, or serum IgE concentration. CONCLUSION: The SNP rs20541 in IL-13 was associated with AHR in Japanese adult asthmatics.

The extracellular and transmembrane domains of the γC and interleukin (IL)-13 receptor α1 chains, not their cytoplasmic domains, dictate the nature of signaling responses to IL-4 and IL-13.

Previously, we demonstrated that the γC subunit of type I IL-4 receptor was required for robust tyrosine phosphorylation of the downstream adapter protein, IRS-2, correlating with the expression of genes (ArgI, Retnla, and Chi3l3) characteristic of alternatively activated macrophages. We located an I4R-like motif (IRS-2 docking sequence) in the γC cytoplasmic domain but not in the IL-13Rα1. Thus, we predicted that the γC tail directed enhanced IRS-2 phosphorylation. To test this, IL-4 signaling responses were examined in a mutant of the key I4R motif tyrosine residue (Y325F) and different γC truncation mutants (γ285, γ308, γ318, γ323, and γFULL LENGTH (FL)) co-expressed in L-cells or CHO cells with wild-type (WT) IL-4Rα. Surprisingly, IRS-1 phosphorylation was not diminished in Y325F L-cell mutants suggesting Tyr-325 was not required for the robust insulin receptor substrate response. IRS-2, STAT6, and JAK3 phosphorylation was observed in CHO cells expressing γ323 and γFL but not in γ318 and γ285 mutants. In addition, when CHO cells expressed γ318, γ323, or γFL with IL-2Rß, IL-2 induced phospho-STAT5 only in the γ323 and γFL clones. Our data suggest that a smaller (5 amino acid) interval than previously determined is necessary for JAK3 activation/γC-mediated signaling in response to IL-4 and IL-2. Chimeric receptor chains of the γC tail fused to the IL-13Rα1 extracellular and transmembrane domain did not elicit robust IRS-2 phosphorylation in response to IL-13 suggesting that the extracellular/transmembrane domains of the IL-4/IL-13 receptor, not the cytoplasmic domains, control signaling efficiency. Understanding this pathway fully will lead to rational drug design for allergic disease.

Interleukin-13 peptide kinoid vaccination attenuates allergic inflammation in a mouse model of asthma.

Asthma is an atopic disorder with increasing frequency and severity in developed nations. Interleukin-13 (IL-13) is one of the most critical mediators of asthma pathology. In the present study, we developed a vaccine comprised of a keyhole limpet hemocyanin-mIL-13 heterocomplex immunogen to persistently neutralize excessive endogenous IL-13. Our results showed that the IL-13 peptide kinoid vaccine could induce sustained and high titer of IL-13-specific IgG when using aluminum hydroxide as an adjuvant, and could suppress the accumulation of eosinophils as well as IL-13 levels in bronchoalveolar lavage fluid (BALF). In addition, total IgE and ovalbumin (OVA)-specific IgE in serum were significantly inhibited. This study also showed that vaccination could prevent airway inflammation and epithelial cell proliferation with goblet cell hyperplasia in a mouse model of acute asthma. In summary, our findings suggest that the IL-13 peptide kinoid can serve as an innovative and effective vaccine against asthma.

Development of reagents to study the turkey's immune response: cloning and characterisation of two turkey cytokines, interleukin (IL)-10 and IL-13.

The cDNAs of two turkey cytokines, interleukin (IL)-10 and IL-13, were cloned using oligonucleotide primers designed from their chicken orthologues. The coding regions of the chicken and turkey genes are highly conserved, with IL-10 and IL-13 exhibiting 94.1% and 90% nucleotide and 92% and 79.9% amino acid identity respectively. Both showed consistent mRNA expression in turkey lymphoid and gut tissues. Expression in non-lymphoid tissues was more variable but generally highest in the skin and trachea. Recombinant turkey IL-10 was expressed and bioactivity demonstrated by inhibition of IFN-γ synthesis from activated splenocytes. Chicken and turkey IL-10 cross-reacted in functional assays.