4-Carvomenthenol ameliorates the murine combined allergic rhinitis and asthma syndrome by inhibiting IL-13 and mucus production via p38MAPK/NF-κB signaling pathway axis.

The aim of this study was to analyze the 4-carvomenthenol (carvo) oral treatment on the experimental model of the combined allergic rhinitis and asthma syndrome (CARAS). BALB/c mice were OVA-sensitized on day zero and 7th (50 µg/mL OVA in 10 mg/mL Al (OH)3) and OVA-challenged (5 mg/mL, 20 µL/animal) for three weeks. In the last week, the animals were dally challenged with aerosol of OVA and the carvo treatment (12.5, 25 or 50 mg/kg) occurred one hour before each OVA-challenge. Data were analyzed and p < 0.05 was considered significant. Carvo (12.5-50 mg/kg) decreased significantly the eosinophil migration into the nasal (NALF) and bronchoalveolar (BALF) cavities as well as on the nasal and lung tissues of sick animals. The treatment also decreased mucus production on both tissue sections stained with PAS (periodic acid-Schiff satin). In addition, the histological analyzes demonstrated that sick mice presented hyperplasia and hypertrophy of the lung smooth muscle layer followed by increasing of extracellular matrix and carvo (50 mg/kg) inhibited these asthmatic parameters. We analyzed the allergic rhinitis signals as nasal frictions and sneezing and observed that carvo decreased these two signals as well as serum OVA-specific IgE titer, type 2 cytokine synthesis, mainly IL-13, with increasing of IL-10 production. Decreasing of IL-13 production corroborated with decreasing of mucus production and these effects were dependent on p38MAPK/NF-κB(p65) signaling pathway inhibition. Therefore, these data demonstrated that a monoterpene of essential oils presents anti-allergic property on an experimental model of CARAS suggesting a new drug prototype to treat this allergic syndrome.

Targeted Therapy for Chronic Spontaneous Urticaria: Rationale and Recent Progress.

Chronic spontaneous urticaria (CSU) is characterized by the presence of wheals, angioedema, or both for at least 6 weeks. It may persist for a long time-up to 50% of the patients have been reported to be symptomatic 5 years after the onset. Some patients can suffer more than one episode of CSU during their lifetime. Considering the recurrences, disabling symptoms, and significant impact on quality of life, proper and effective treatment of CSU is critical. The use of antihistamines (AHs) is still the mainstay of treatment. However, given the low rates of response to AHs (38.6% and 63.2% to standard doses and higher doses, respectively), the complete control of symptoms seems difficult to attain. The use of omalizumab for CSU has been a major breakthrough in the care of patients with CSU. However, the partial response and lack of response to omalizumab in a subgroup of patients, as high as 70% in some studies, make the development of alternative treatments desirable. Ever-increasing knowledge on the pathogenesis is making new target molecules available and enabling drug development for CSU. In addition to drug repurposing as in anti-IL-4/13, IL-5, and IL-17 antibodies, novel targeted therapy options such as ligelizumab and Bruton's tyrosine kinase inhibitors are currently undergoing clinical trials and will be available in the near future. This article reviews the current challenges in the treatment of CSU, the pathogenesis and potential target molecules, and the rationale for novel treatments and their rapidly developing status.

The use of biologic therapies for the management of pediatric asthma.

With better understanding of the role of type 2 inflammation in allergic asthma, there has been progress made in the development of new biologic therapies targeting these specific pathways. This review will consider diagnostic criteria for using biologic therapies for pediatric asthma with special emphasis on populations that are likely to benefit the most from particular therapies. With the exception of the anti-immunoglobulin E, omalizumab, very few studies have been published on the efficacy and safety of biologic therapies in children, particularly anti-interleukin-5 (IL5) and anti-IL4/IL13 therapies. The review will highlight the scarcity of published data in pediatric-specific populations. In addition, we will consider the cost-effectiveness as well as potential long-term consequences of biologic therapies in pediatric asthma.

Dupilumab: a new paradigm for the treatment of allergic diseases

Moderate and severe forms of allergic diseases such as atopic dermatitis and asthma are a challenge for clinicians. In these conditions, which severely affect the quality of life of the patient and frequently have associated allergic comorbidities, the therapeutic options are often very limited. Treatment with systemic corticosteroids and immunosuppressants has adverse effects in the long term, and a significant proportion of patients remain refractory to therapy. In this context, the emerging biological drugs constitute a truly innovative therapeutic approach. A leading example is dupilumab, a monoclonal antibody targeting the α chain of the interleukin (IL)-4 receptor. Dupilumab inhibits the biological effects of the cytokines IL-4 and IL-13, which are key drivers in the TH2 response. The efficacy and safety profile of dupilumab in the treatment of allergic diseases has been tested for more than 10 years in a variety of large clinical trials in atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyposis, and eosinophilic esophagitis. In 2017, the United States Food and Drug Administration and the European Medicines Agency approved the use of dupilumab for the treatment of adult patients with moderateto-severe atopic dermatitis whose disease is not adequately controlled with prescribed topical treatment. The results of phase III clinical studies of dupilumab in patients with persistent, uncontrolled asthma have been highly promising. The safety and tolerability profile of dupilumab has proven to be very favorable in long-term clinical trials. In this review, we focus on the mechanism of action of dupilumab, its development, and its impact on daily clinical practice in allergic diseases

Las formas clínicas moderadas y graves de enfermedades alérgicas comunes como la dermatitis atópica o el asma constituyen un reto para los clínicos. En estos casos, que afectan intensamente la calidad de vida del paciente y con frecuencia conllevan otras enfermedades alérgicas asociadas, las opciones terapéuticas son a menudo muy limitadas. El tratamiento con corticosteroides sistémicos o inmunosupresores tiene efectos adversos a largo plazo y una proporción significativa de pacientes se muestra refractaria a la terapia. En este contexto, los nuevos fármacos biológicos, dirigidos a la base inmunológica de la enfermedad, ofrecen un enfoque terapéutico verdaderamente innovador. Un ejemplo destacado de estos fármacos es dupilumab, un anticuerpo monoclonal dirigido contra la cadena alfa del receptor de la interleucina (IL)-4. Dupilumab inhibe los efectos biológicos de las citoquinas IL-4 e IL-13, unos de los principales efectores de la respuesta Th2. La efectividad y seguridad de dupilumab en el tratamiento de enfermedades alérgicas se han probado durante más de diez años en una variedad de grandes ensayos clínicos en dermatitis atópica, asma, rinosinusitis crónica con poliposis nasal y esofagitis eosinofílica. La FDA y la EMA aprobaron en 2017 el uso de dupilumab en el tratamiento de pacientes adultos con dermatitis atópica moderada o grave que no se controla adecuadamente con tratamiento tópico. Los estudios clínicos de Fase 3 de dupilumab en pacientes con asma persistente no controlada también han sido muy prometedores. En los ensayos clínicos a largo plazo la seguridad y tolerabilidad de dupilumab ha demostrado ser muy elevada. En esta revisión nos hemos centrado en el mecanismo de acción de dupilumab, su desarrollo como fármaco y su impacto en la terapia de enfermedades alérgicas

Atopic dermatitis: phototherapy and systemic therapy.

The majority of atopic dermatitis (AD) patients respond satisfactorily to gentle bathing, frequent moisturizing, and topical medications. Second-line therapies for AD should be used in recalcitrant cases or in patients with uncontrolled disease despite compliance with first-line measures and avoidance of allergens. Recommended advanced therapies include phototherapy, especially narrowband ultraviolet B, systemic immunosuppressants, and a new biologic agent. Few studies have compared head-to-head efficacy of the different immunosuppressant therapies such as cyclosporine, methotrexate, azathioprine and mycophenolate mofetil. Therefore, the agent used is based on provider and patient preferences and can be decided on a case-by-case basis.

Dupilumab in the treatment of moderate-to-severe atopic dermatitis.

INTRODUCTION: Atopic dermatitis is a common inflammatory skin disease with an increasing prevalence. Treatment of patients suffering from mild or moderate disease includes the use of emollients and topical glucocorticoids or topical calcineurin inhibitors. Patients with chronic and severe atopic dermatitis where topical therapy is usually insufficient require the use of systemic immunosuppressive drugs, which is often limited due to toxicity and severe adverse effects. Areas covered: This review summarizes the literature on the mechanism of action, clinical efficacy and safety of dupilumab, a monoclonal antibody that targets the α-subunit of the interleukin-4 receptor (IL-4Rα) leading to the inhibition of both the IL-4 and IL-13 pathways. A literature search was performed on Pubmed and ClinicalTrials.gov using key words 'dupilumab', 'REGN668', 'IL-4'/'IL-13' and 'atopic dermatitis'. Expert commentary: Dupilumab offers an innovative therapeutic approach for moderate-to-severe atopic dermatitis. It is not approved for clinical use in any country yet; however, due to its excellent clinical efficacy and a favorable safety profile, dupilumab may revolutionize the treatment of moderate-to-severe atopic dermatitis in the next upcoming years.

Reversal of IL-13-induced inflammation and Ca(2+) sensitivity by resolvin and MAG-DHA in association with ASA in human bronchi.

The aim of this study was to investigate the effects of resolvin D1 (RvD1), as well as the combined treatment of docosahexaenoic acid monoglyceride (MAG-DHA) and acetylsalicylic acid (ASA), on the resolution of inflammation markers and Ca(2+) sensitivity in IL-13-pretreated human bronchi (HB). Tension measurements performed with 300 nM RvD1 largely abolished (50%) the over-reactivity triggered by 10 ng/ml IL-13 pretreatment and reversed hyper Ca(2+) sensitivity. Addition of 300 nM 17(S)-HpDoHE, the metabolic intermediate between DHA and RvD1, displayed similar effects. In the presence of 100 µM ASA (a COX inhibitor), the inhibitory effect of 1 µM MAG-DHA on muscarinic tone was further amplified, but not in the presence of Ibuprofen. Western blot analysis revealed that the combined treatment of MAG-DHA and ASA upregulated GPR-32 expression and downregulated cytosolic TNFα detection, hence preventing IκBα degradation and p65-NFκB phosphorylation. The Ca(2+) sensitivity of HB was also quantified on ß-escin permeabilized preparations. The presence of ASA potentiated the inhibitory effects of MAG-DHA in reducing the Ca(2+) hypersensitivity triggered by IL-13 by decreasing the phosphorylation levels of the PKC-potentiated inhibitor protein-17 regulatory protein (CPI-17). In summary, MAG-DHA combined with ASA, as well as exogenously added RvD1, may represent valuable assets against critical AHR disorder.

Zingiber mioga (Thunb.) Roscoe attenuates allergic asthma induced by ovalbumin challenge.

Zingiber mioga (Thunb.) Roscoe (ZM) is a traditional medicine, used to treat inflammatory diseases. The present study aimed to evaluate the inhibitory effects of ZM on the inflammatory response in lipopolysaccharide (LPS)­stimulated RAW264.7 murine macrophage cells and in a mouse model of ovalbumin (OVA)­induced allergic asthma. Mice received OVA sensitization on day 0 and 14, and were challenged with OVA between days 21 and 23. ZM was administered to the mice at a dose of 30 mg/kg, 1 h prior to OVA challenge. In LPS­stimulated RAW264.7 cells, ZM significantly decreased nitric oxide (NO) and tumor necrosis factor (TNF)­α production in a concentration­dependent manner, and mRNA expression of inducible NO synthase (iNOS), TNF­α and matrix metalloproteinase (MMP)­9 was reduced. In addition, treatment with ZM decreased the inflammatory cell count in bronchoalveolar lavage fluid from the mice, and reduced the expression of interleukin (IL)­4, IL­5, IL­13, eotaxin and immunoglobulin E. ZM also reduced airway hyperresponsiveness in OVA­challenged mice, and attenuated the infiltration of inflammatory cells and mucus production in the airways, with a decrease in the expression of iNOS and MMP­9 in lung tissue. In conclusion, the results of the present study indicate that ZM effectively inhibits inflammatory responses. Therefore, it may be that ZM has potential as a therapeutic agent for use in inflammatory diseases.

Targeting the IL-4/IL-13 signaling pathway sensitizes Hodgkin lymphoma cells to chemotherapeutic drugs.

Hodgkin/Reed-Sternberg lymphoma (HL) is a clonal B-cell-related malignancy. Although many patients with HL can be cured by the current regimen of high-dose multi-agent chemotherapy, the treatment causes high risks of later pathologies including secondary malignancies. This fact highlights the demand to develop rational treatment for HL. Survival and growth of HL cells are largely dependent on their microenvironment. In this study, using the HL cell lines L1236 and KM-H2 as model systems, we investigated the role of IL-4/IL-13 signaling in regulation of drug sensitivity and resistance in HL. We show that specific blocking of IL-4 and IL-13-mediated STAT6 activation by either an IL-4-binding fusion protein APG598 or an IL-4R antagonist APG201 (R121D/Y124D) renders HL cells more prone to apoptotic killing by chemotherapeutic drugs such as Mitomycin C, 5-Fluorouracil, Etopside, Doxorubicin and Paclitaxel. This effect is due to inhibition of STAT6-mediated elevation of expression of the anti-apoptotic Bcl-2 family protein Bcl-xL. Employing ChIP analysis in combination with APG201 or STAT6-specific siRNA we identified a defined STAT6-binding site in the Bcl-xL promoter region from -1967 to -1957 of the transcription start site. Our data demonstrate that the IL-4/IL-13-STAT6-Bcl-xL axis may be an important target for HL treatment. This study also suggests that combination of classical chemotherapeutic drugs with the IL-4/IL-13 antagonists may enhance efficacy and reduce risks of toxicity from high dose of drugs in HL treatment.

n-3 Fatty acids inhibit transcription of human IL-13: implications for development of T helper type 2 immune responses.

Fish oil supplementation during pregnancy has been associated with lower levels of cord blood IL-13, suggesting that the administration of n-3 fatty acids may attenuate the development of allergic disease. The present study aimed to investigate the mechanism by which n-3 fatty acid administration influences the production of IL-13. Pregnant BALB/c mice were fed nutritionally complete high-fat diets (15 %, w/w) with an n-3 fatty acid-enriched (DHA 1 %, w/w) or control diet (0 % DHA) immediately following delivery. Pups were exposed during suckling and weaned to the maternal diet for the remainder of the study. The production of IL-13, IL-4, IL-10 and interferon-γ from the splenocytes of ovalbumin (ova)-sensitised animals was assessed following in vitro ova stimulation or unstimulated conditions. Human T helper type 2 (Th2) cells were mitogen-stimulated in the presence or absence of DHA (10 µM) and assessed for IL-13 and IL-4 expression using intracellular flow cytometry. The influence on transcriptional activation was studied using a human IL-13 promoter reporter construct and electromobility shift assay. Ova-activated splenocytes from DHA-fed mice produced less IL-13 (57.2 (se 21.7) pg/ml) and IL-4 (7.33 (SE 3.4) pg/ml) compared with cells from the animals fed the control diet (161.5 (SE 45.0), P< 0.05; 33.2 (SE 11.8), P< 0.05). In vitro, DHA inhibited the expression of IL-13 protein from human Th2 cells as well as transcriptional activation and binding of the transcription factors cyclic AMP response element binding and activating transcription factor 2 to the human IL-13 promoter. These data indicate the potential of n-3 fatty acids to attenuate IL-13 expression, and suggest that they may subsequently reduce allergic sensitisation and the development of allergic disease.

Pitrakinra for asthma.

IMPORTANCE OF THE FIELD: In asthma IL-4 and IL-13 have been demonstrated to play major pathogenic roles and therefore their blockade would potentially represent a plausible therapeutic approach. AREAS COVERED IN THIS REVIEW: Pitrakinra is a dual IL-4/IL-13 inhibitor currently under development for asthma and the existing preclinical and clinical data are discussed. WHAT THE READER WILL GAIN: Inhaled pitrakinra demonstrated a good anti-inflammatory potential and a good safety profile on a short-term basis but its place in asthma therapy is still to be found. TAKE HOME MESSAGE: Specific anticytokine therapies might in the near future reshape asthma therapy.

Blackcurrant proanthocyanidins augment IFN-gamma-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells.

Epidemiological studies reveal that fruit consumption reduces the prevalence of airway inflammation and childhood asthma. In particular, blackcurrant polyphenolic extracts have been shown to alleviate lung inflammation. Since IL-4-stimulated eotaxin-3 (CCL26) secretion is a major factor in the continuous eosinophil recruitment observed in atopic asthma, our focus was to evaluate the effectiveness of blackcurrant polyphenolic compounds on CCL26 secretion in human alveolar epithelial cells. Our results indicate that a proanthocyanin-enriched blackcurrant extract (BC-P), but not anthocyanin-enriched blackcurrant extract suppressed both IL-4- and IL-13-stimulated CCL26 secretion in a dose-dependent manner. Furthermore pre-incubation of cells with BC-P caused a time-dependent suppression of IL-4-stimulated CCL26 secretion. Moreover, epigallocatechin (EGC), and to a lesser extent epicatechin, metabolites identified in the proanthocyanidin extract, suppressed IL-4-stimulated CCL26 secretion. EGC was also effective at reducing the cellular phosphorylated STAT-6/STAT-6 ratio. Furthermore, both BC-P and purified EGC potentiated the ability of IFN-gamma to suppress IL-4-stimulated CCL26 secretion. The progression of an allergic immune response is complex, identifying plant compounds that target specific cellular events and complement the body's own immune actions is important for the development of functional foods. Our findings support the potential for blackcurrant polyphenolic compounds to reduce eosinophil recruitment and alleviate eosinophilic-driven airway inflammation.

IL-4/IL-13 antagonist DNA vaccination successfully suppresses Th2 type chronic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic disease with a Th2-type-cytokine dominant profile. Several cytokines and related peptides have been used for the treatment of AD but they were ineffective because of their limited biological half-life. We have recently developed a highly efficient mouse dominant negative interleukin (IL)-4/IL-13 antagonist (IL-4DM), which blocks both IL-4 and IL-13 signal transductions. OBJECTIVE: To examine the effects of IL-4DM in vivo in an AD model induced by the repeated exhibition of oxazolone (OX). METHODS: Plasmid DNA was injected intraperitoneally to cause an experimental AD-like dermatitis. The effect was evaluated by ear thickness, histological findings, and mast cells counts in the inflamed skin. The plasma IgE and histamine levels were measured. Cytokine production in skin and splenocytes were also analysed. RESULTS: Mice treated with control plasmid developed marked dermatitis with mast cells and eosinophil infiltration, and had increased plasma IgE and histamine levels with a Th2 type splenocyte cytokine profile. Treatment with mouse IL-4 DNA augmented the ear swelling and thickness with an increased dermal eosinophil count, plasma histamine level, and production of splenocyte IL-4. However, IL-4DM treatment successfully controlled the dermatitis, decreased the mast cell and eosinophil count, and suppressed plasma IgE and histamine levels. Splenocytes produced an increased level of IFN-gamma. CONCLUSION: These data showed that the simultaneous suppression of IL-4/IL-13 signals successfully controlled Th2-type chronic dermatitis. IL-4DM DNA treatment is a potent therapy for AD and related diseases.

Clara cell 16-kd protein downregulates T(H)2 differentiation of human naive neonatal T cells.

BACKGROUND: Levels of the Clara cell 16-kd protein (CC16) are lower in plasma and bronchoalveolar lavage fluid from adults with asthma relative to those seen in healthy control subjects, and CC16 inhibits the T(H)2 cytokine production from murine T cells. OBJECTIVE: We sought to determine the plasma levels of CC16 in infants and to investigate whether CC16 might inhibit the T(H)2 cytokine production from neonatal T cells. METHODS: Cord blood and blood samples at 4, 18, and 36 months of age were taken from 64 children prospectively, and CC16 levels were analyzed in plasma. Cord monocyte-derived dendritic cells (DCs) were pulsed with birch allergen extract alone or together with CC16 or prostaglandin D(2) receptor inhibitors, after which autologous naive CD4(+) T cells were added to the DCs. The production of IL-5, IL-13, and IFN-gamma was measured by means of ELISA and flow cytometry. RESULTS: The plasma levels of CC16 in children peaked at 4 months. CC16 did not directly affect the cytokine production from human T(H)2 cells. However, CC16 inhibited birch pollen extract-stimulated T(H)2 differentiation of naive T cells through the DC. Inhibition of the prostaglandin D(2) receptors did not consistently result in suppressed T(H)2 differentiation. CONCLUSION: The production of CC16 seems to peak early in life, and CC16 has an inhibitory effect on T(H)2 cell differentiation from human infants by affecting DCs. CLINICAL IMPLICATIONS: CC16 is an immunoregulatory protein, and its inhibitory effect on T(H)2 cell differentiation might be of importance in the pathogenesis of allergy in infants.

Single dose topical corticosteroid inhibits IL-5 and IL-13 in nasal lavage following grass pollen challenge.

BACKGROUND: Nasal lavage is a noninvasive method of obtaining inflammatory exudates following nasal allergen challenge (NAC), and permits cells and released mediators to be evaluated. OBJECTIVE: To determine the effects of a single dose of topical steroid on eosinophils and levels of chemokines and cytokines in nasal lavage fluid following NAC in patients with allergic rhinitis. METHODS: Patients with grass pollen seasonal allergic rhinitis (n = 32) out of the allergy season received either nasal budesonide (100 microg per nostril) or matched placebo before allergen challenge in a double blind two-way crossover design. A semi-automated mixed bead array system was employed to measure multiple chemokines and cytokines in small volumes (50 microl) of nasal lavage supernatants. RESULTS: Following NAC there was a rapid onset of nasal symptoms together with nasal eosinophilia, and the appearance of IL-5 and IL-13 in lavages between 4 and 8 h. Elevated levels of eotaxin, RANTES, IL-8 and MCP-1 were also detected following allergen challenge. A single dose of nasal budesonide caused a decrease in symptoms (P < 0.05) and nasal eosinophils (P < 0.05) with selective abrogation of IL-5 and IL-13 responses (P < 0.05), but a lack of effect on levels of eotaxin, RANTES, IL-8 and MCP-1. CONCLUSION: This study suggests that a single dose of nasal steroid has the capacity to selectively abolish IL-5 and IL-13 responses following NAC. This model should be convenient for testing novel anti-inflammatory and immunoregulatory agents intended for the treatment of allergic rhinitis.

Suppression of T cell signaling by polyunsaturated fatty acids: selectivity in inhibition of mitogen-activated protein kinase and nuclear factor activation.

Polyunsaturated fatty acids (PUFAs) are known to suppress inflammatory and autoimmune responses and, therefore, clinical applications of PUFAs as immunomodulatory substances are extensively studied. PUFAs are known to inhibit T cell responses, but with respect to TCR/CD3-mediated signal transduction only a block in CD3-induced phospholipase Cgamma1/calcium signaling has been shown so far. In this study, we investigated PUFA-mediated changes in downstream T cell signal transduction. We show that among the mitogen-activated protein kinase families activation of c-Jun NH(2)-terminal kinase, but not phosphorylation of extracellular signal-regulated kinase-1/-2 or p38 is inhibited. CD3/CD28-induced activity of NF-AT was markedly reduced by PUFA treatment, while activation of other nuclear receptors (AP-1 and NF-kappaB) remained unaltered. Furthermore, IL-2 promoter activity, IL-2 and IL-13 mRNA levels, IL-2 secretion, and IL-2R alpha-chain expression were significantly diminished by PUFA treatment, whereas the expression of IFN-gamma, IL-4, IL-10, and CD69 remained essentially unaffected by PUFAs. In conclusion, PUFA treatment of T cells inhibits selectively c-Jun NH(2)-terminal kinase and NF-AT activation, resulting in diminished production of IL-2 and IL-13.

Therapeutic effect of IL-13 immunoneutralization during chronic experimental fungal asthma.

IL-13 and IL-4 are key contributors to the asthmatic phenotype. The temporal role of these cytokines in airway function, inflammation, and remodeling were assessed in a chronic murine model of Asperigillus fumigatus-induced allergic asthma. IL-13 and IL-4 protein levels were significantly elevated by 30 days after conidia challenge in A. fumigatus-sensitized mice. Furthermore, IL-13Ralpha1 mRNA expression was significantly elevated 7 days after conidia challenge and remained elevated until day 21. In contrast, IL-13Ralpha2 mRNA expression, although constitutively expressed in naive lung, was absent in the lungs of A. fumigatus-sensitized mice both before and after conidia challenge. Membrane-bound IL-4R mRNA expression was significantly elevated 7 days after conidia challenge; however, soluble IL-4R mRNA expression was increased 30 days after conidia challenge. Immunoneutralization of IL-13 between days 14 and 30 or days 30 and 38 after fungal sensitization and challenge significantly attenuated airway hyperresponsiveness, collagen deposition, and goblet cell hyperplasia at day 38 after conidia challenge; however, the effects of IL-4 immunoneutralization during the same time periods were not as marked. IFN-gamma and IL-12 release after Aspergillus Ag restimulation was elevated from spleen cells isolated from mice treated with IL-4 anti-serum compared with IL-13 anti-serum or normal rabbit serum-treated mice. This study demonstrates a pronounced therapeutic effect of IL-13-immunoneutralization at extended time points following the induction of chronic asthma. Most importantly, these therapeutic effects were not reversed following cessation of treatment, and IL-13 anti-serum treatment did not alter the systemic immune response to Ag restimulation, unlike IL-4 immunoneutralization. Therefore, IL-13 provides an attractive therapeutic target in allergic asthma.

Il-4 and IL-13, but not IL-10, protect human synoviocytes from apoptosis.

Interleukin-4, which has been contemplated for the treatment of rheumatoid arthritis and/or osteoarthritis because of its anticatabolic properties, has also been shown to modulate apoptosis. Because inadequate apoptosis is thought to contribute to synovial hyperplasia, we have investigated the ability of IL-4 and other Th2 cytokines to protect human synovial cells from apoptosis. Human synoviocytes or synovial explants were pretreated with IL-4, IL-10, and IL-13 before exposure to NO donor sodium-nitro-prusside (SNP). Apoptosis was evaluated by microscopy, annexin V-FITC, 3-(4,5-dimethylthiazol-2-gl)-5-(3-carboxymethoxylphenyl)-2-(4-sulphophenyl-2H: tetrazolium inner salt (MTS) test, pulse field gel electrophoresis, and a method proposed in this study based on (32)P Klenow end labeling of high m.w. DNA. Pretreatment by IL-4 or IL-13, but not IL-10, protected human synoviocytes from apoptosis induced by SNP. Even at doses as high as 2 mM SNP, up to 86% and 56% protection was achieved, after IL-4 and IL-13 treatment, respectively. Cell survival was dependent on IL concentration. IL-4 and IL-13 also had antiapoptotic effects on SNP-treated human synovial explants. Effects of IL-4 and IL-13 varied in the presence of phosphatidylinositol-3 kinase and protein kinase C inhibitors, implying the involvement of these pathways in antiapoptotic signaling. Antiapoptotic effects were dramatically inhibited by LY294002, and partially by the protein kinase C inhibitor Gö 6976, while insulin-like growth factor increased synoviocyte survival. The possibility that IL-4 and IL-13 may enhance synovial expansion in vivo by their antiapoptotic effects is discussed.