Atopic-like Dermatitis Research Articles

IL-31RA and TRPV1 Expression in Atopic Dermatitis Induced with Trinitrochlorobenzene in Nc/Nga Mice.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Interleukin 31 (IL-31), a novel cytokine in AD, causes pruritus, typically characteristic of AD patients. The transient receptor potential vanilloid type 1 (TRPV1) is a cation channel activated by diverse noxious stimuli that has been studied in a variety of pruritic skin diseases. In this study, the AD animal model was generated by administering the hapten, trinitrochlorobenzene (TNCB), to Nc/Nga mice, and the degree of expression of the IL-31 receptor alpha (IL-31RA) and TRPV1 in the skin of these atopic models was evaluated. The Nc/Nga mice were divided into 3 groups: control, TNCB 2-weeks treated, and TNCB 8-weeks treated. After inducing AD, the skin lesions in each group were scored and compared, and the histology of the skin lesions and the IL-31RA and TRPV1 expression for each group were evaluated by analyzing immunohistochemistry. The results show a significant difference in the skin lesion scores between the groups. The immunohistochemistry evaluation highlighted the remarkable expression of IL-31RA and TRPV1 in the nerve fibers of the TNCB 8-weeks-treated group. We thus confirmed that the long-term application of TNCB induced chronic atopic-like dermatitis and that IL-31RA and TRPV1 were overexpressed in the peripheral nerve fibers in this AD model.

Predictive factors of atopic-like dermatitis induced by IL-17A inhibitors in patients with psoriasis: A 2-year follow-up study.

Atopic-like dermatitis (ALD) is a common side effect of interleukin-17A (IL-17A) inhibitors. To determine the prevalence, risk factors, outcomes and treatment of ALD in a cohort of psoriasis patients treated with IL-17A inhibitors. This retrospective study included 226 psoriasis patients treated with an IL-17A inhibitor in our dermatology department between July 2020 and July 2022. The patients were reviewed over 2 years. A logistic regression model in rare events data (relogit) was used to predict the risk factors for ALD. Of the 226 patients, 14 had ALD. Data including age, body mass index, IL-17A inhibitor use, personal and family history of atopic disease, pet ownership history, and immunoglobulin E (IgE) levels were analysed using the relogit regression model. It indicated a personal history of atopic disease (odd ratio [OR] 27.830, 95% confidence interval [CI] 3.801-203.770; p = 0.001) and elevated IgE levels (OR 5.867, 95% CI 1.131-30.434; p = 0.035) as independent predictors of incident ALD. In one patient, anti-IL-17A therapy was discontinued, and treatment was switched to tofacitinib. Thirteen patients who continued with IL-17A inhibitor were treated with topical therapy and/or antihistamines, and their ALD was partially or completely resolved. In this study, the incidence rate of ALD was 6.19%. Elevated IgE levels and a personal history of atopic disease were found to be the risk factors for ALD. Our study findings suggest that treatment should be provided based on the severity of psoriasis and incident ALD. Prior to treatment, psoriasis patients who have the risk factors for ALD should be informed of the possible development of ALD, and alternative psoriatic therapeutic options should be considered if severe ALD develops.

Phyllostachys nigra Munro var alleviates inflammatory chemokine expression and DNCB-induced atopic-like dermatitis in BALB/c mice

Ethnopharmacological relevancePhyllostachys nigra (PN) is an herbal medicine that originates from the inner bark of Phyllostachys nigra Munro var. henosis Stapf or Phyllostachys bambusoides Siebold et Zuccarini. It has long been used to relieve fever and to treat diarrhea and inflammation. PN has been shown to possess inhibitory effects on pneumonia, intestinal inflammation, tumors, and fatigue. However, its potential efficacy in the treatment of atopic dermatitis (AD) has not been extensively studied or reported. Aim of the studyThe objective of this research was to investigate the impact of PN on HaCaT and HMC-1 cells, as well as its potential in an experimental model of AD induced by 1-chloro-2,4-dinitrobenzene (DNCB). MethodsWe analyzed the anti-inflammatory efficacy of PN in HaCaT cells and HMC-1 cells using ELISA and PCR, and investigated invasion of inflammatory cell, change of dermis and epidermis, and the SCORAD index in AD-like mice model. We also measured the MAPK signaling pathway using the dorsal tissue of mice. ResultsOur results show that PN reduced the expressions of TARC, GM-CSF, TNF-α, MCP-1, and IL-6 in vitro. PN also decreased the SCORAD index, thickening of epidermis and dermis, and inhibited the invasions of mast cells and eosinophils as well as CD4+ T and CD8+ T cells. Furthermore, PN suppressed the level of IgE and IL-6, and also inhibited the MAPK phosphorylation in the dorsal skin. ConclusionThese results demonstrate that PN could be an effective alternative medicine for allergic inflammatory disease.

Immunoglobulin E-specific allergens against leaf in serum of dogs with clinical features of grass leaf allergy.

Grass leaf has been suspected of causing immunoglobulin (Ig)E-mediated immediate hypersensitivity reactions in humans and dogs. However, most studies in this area are case-control studies without in vitro data showing the involvement of IgE in the reaction. Laboratory studies have demonstrated the reactivity to a 50-55 kDa protein with clinical signs immediately after contact with grass leaf material. The clinical findings of dogs with atopic-like dermatitis immediately after contact with grass leaf material suggest the involvement of grass leaves as the allergen source. This study was designed to test the IgE-reactivity of grass leaf proteins in dogs with clinical signs and positive scratch test results against grass leaf material. The serum of 41 patients with a history of allergy and suspected to grass leaf material was immunoblotted against grass leaf extracts from five suspected grass species. The IgE-positive blots were separated with 2D gel electrophoresis and analysed with mass spectrometry (MS). Commercially supplied proteins were used to validate immunoblot activity. The serum of 25 dogs diagnosed with grass dermatitis had positive IgE-specific immunoblot against one or more grass leaf extracts. The MS data indicated a reactive band at 55 kDa to be beta-amylase or RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) large subunit (RbLS). All tested dog sera showed IgE-reactivity with beta-amylase and some with RbLS. Canines with clinical signs of grass-related dermatitis had IgE-reactivity against grass leaf proteins. Serum IgE-reactivity to beta-amylase and RuBisCO large subunit may indicate that these proteins act as allergens, possibly causing pruritus and skin lesions.

Evaluation of the Anti-Atopic Dermatitis Effects of α-Boswellic Acid on Tnf-α/Ifn-γ-Stimulated HaCat Cells and DNCB-Induced BALB/c Mice.

Boswellic acids, triterpenoids derived from the genus Boswellia (Burseraceae), are known for their anti-inflammatory and anti-tumor efficacy. Atopic dermatitis is a chronic, non-infectious inflammatory skin disease. However, the effects of α-boswellic acid on atopic dermatitis have not been studied. Therefore, in this study we examined the expression level of pro-inflammatory cytokines, histopathological analysis, and physiological data from BALB/c mice with atopic-like dermatitis induced by 2,4-dinitrochlorobenzene and TNF-α/IFN-γ-stimulated HaCaT cells to better understand the agent’s anti-atopic dermatitis efficacy. First, we found that α-boswellic reduced the epidermal thickening, mast cell numbers, and dermal infiltration of 2,4-dinitrochlorobenzene-induced atopic-like dermatitis in BALB/c mice. Furthermore, we also found that α-boswellic acid can restore transepidermal water loss and skin reddening in mice. In human keratinocytes inflamed by TNF-α/IFN-γ, α-boswellic acid inhibited MAP kinase activation and showed a reduction in NF-κB nuclear translocation. Finally, α-boswellic acid can reduce the expression level of cytokines (IL-1β, IL-6, and IL-8) following the stimulation of TNF-α/IFN-γ in HaCaT cells. Taken together, our study suggests that α-boswellic acids are a potential component for the development of anti-atopic dermatitis drugs.

Intradermal reactivity to two concentrations of pollen extracts in atopic dogs.

Intradermal test (IDT) is used widely for determination of allergens to include in allergen-specific immunotherapy (AIT). The optimal concentration of allergen solutions used for testing has not been established in atopic dogs. Inadequate concentrations could lead to falsely negative test results and lack of inclusion of important allergens in AIT. To compare IDT reactivity to two concentrations of five pollen extracts and determine the effect on ASIT prescription. Atopic dogs (n=67) had IDT results including all of the allergens of interest. Medical records from a veterinary teaching hospital were reviewed for all atopic dogs undergoing IDT over a three year period. In addition to the hospital's standard IDT concentration of 1,000 PNU/mL for pollen allergens, five pollen allergens of higher concentration (3,000-8,000 PNU/mL) had been added at the beginning of that period. The IDT scores for the standard test concentration of each of the five allergens were compared to the scores for the higher concentration. Positive reactions occurred much more commonly to the higher test concentration for each of the paired allergens (P<0.05, chi-square). The AIT formulation was different in 58% of the dogs from what it would have been without the higher concentration allergens. The current standard IDT concentration of 1,000 PNU/mL for pollen allergens is likely too low, possibly resulting in inaccurate AIT formulations. This might explain treatment failures and the incorrect diagnosis of atopic-like dermatitis. Further work is needed to establish optimal allergen test concentrations.

MALT1-Deficient Mice Develop Atopic-Like Dermatitis Upon Aging.

MALT1 plays an important role in innate and adaptive immune signaling by acting as a scaffold protein that mediates NF-κB signaling. In addition, MALT1 is a cysteine protease that further fine tunes proinflammatory signaling by cleaving specific substrates. Deregulated MALT1 activity has been associated with immunodeficiency, autoimmunity, and cancer in mice and humans. Genetically engineered mice expressing catalytically inactive MALT1, still exerting its scaffold function, were previously shown to spontaneously develop autoimmunity due to a decrease in Tregs associated with increased effector T cell activation. In contrast, complete absence of MALT1 does not lead to autoimmunity, which has been explained by the impaired effector T cell activation due to the absence of MALT1-mediated signaling. However, here we report that MALT1-deficient mice develop atopic-like dermatitis upon aging, which is preceded by Th2 skewing, an increase in serum IgE, and a decrease in Treg frequency and surface expression of the Treg functionality marker CTLA-4.

Spotlight on brodalumab in the treatment of plaque psoriasis: the evidence to date.

The IL-17/IL-23 axis is now understood to influence psoriasis, and the development of novel IL-17 inhibitor medications marks a sea change in the treatment of psoriasis. Brodalumab is a recombinant, fully human immunoglobulin IgG2 monoclonal antibody specifically targeted against IL-17RA. This article discusses the mechanism of action and the efficacy and safety profile of brodalumab presented in the literature. Brodalumab, the latest approved anti-IL-17-class medication, is the only one that exerts its effects on IL-17C as well as on IL-17A and IL-17F, blocking the shared IL-17 receptor A. In this sense, considering the recent evidence, brodalumab could have beneficial effects not only on psoriasis, but also on atopic dermatitis. It could also serve as a therapeutic alternative in patients who develop paradoxical eczematous reactions or atopic-like dermatitis during treatment with other anti-IL-17A (secukinumab, ixekizumab).

Mitigating effect of fermented Korean red ginseng extract with yeast and probiotics in 1-chloro-2,4-dinitrobenzene-induced skin allergic inflammation

Atopic dermatitis (AD) frequently affects both infants and adults, impacting on the quality of life of the individual and imposing a significant psychosocial burden. The efficacy against AD-like skin lesions of the fermented form of Korea red ginseng (FRG), that contains ginsenoside metabolites, has not been investigated. FRG was prepared after fermentation of Korean red ginseng (KRG) extract in the presence of yeast and probiotics. The effects of FRG on skin allergic inflammation were then investigated by examining the frequency of scratching, and assessing the levels of representative allergic markers in 1-chloro-2,4-dinitrobenzene (DNCB)-challenged Balb/c mice. After two weeks of DNCB challenge, vehicle, dexamethasone (positive control), and FRG (10 and 50 μg/mL) were applied topically on skin lesions for 2 weeks. At the end of the experiment, scratching behavior, immunoglobulin E (IgE), and interleukin 4 (IL-4) levels were measured. The status of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) were determined by immunoblot analysis in DNCB-treated primary splenocytes. Topical administration of FRG significantly suppressed scratching behavior, serum IgE, and IL-4 levels (P<0.05, n=5/group). In addition, FRG treatment significantly decreased the mRNA expression levels of IL-4 and IL-10 in DNCB-exposed splenocytes (P<0.05, n=6/group). Moreover, FRG suppressed DNCB-induced phosphorylation of p38 MAPK and activation of NF-κB. FRG could ameliorate skin allergic inflammation via suppression of p38 MAPK and NF-κB. Therefore, FRG may be a potential therapeutic agent for the prevention and/or treatment of atopic-like dermatitis.

Inhibitory effects of Aristotelia chilensis water extract on 2,4-Dinitrochlorobenzene induced atopic-like dermatitis in BALB/c Mice.

Maqui berry (Aristotelia chilensis) has been reported to have anti-glycation, anti-inflammation, lipogenesis-inhibiting activities highly related to its anti-oxidation function, but practical efficacy studies on immunological mechanisms for atopic dermatitis, have not been reported yet. This study investigated the immune regulation mechanism of Aristotelia chilensis water extract (ACWE) related to atopic-like dermatitis . Antioxidant and anti-inflammatory effects of ACWE was assayed. Atopy inhibitory effect was evaluated using in vitro cell study and in vivo 2,4-dinitrochlorobenzene (DNCB)-induced mouse atopic-like dermatitis model. ACWE has good antioxidant activities, and atopic indications were improved in ACWE group in DNCB-induced atopic-like dermatitis model of BALB/c mice. In spleen cells from mice, ACWE increased interferon-gamma (IFN-γ) levels, and decreased interleukin-4 (IL-4) levels compared with the DNCB control. ACWE was efficacious for atopic dermatitis which indicates that ACWE might have potential as an agent for atopic dermatitis.

Comparison of demographic data, disease severity and response to treatment, between dogs with atopic dermatitis and atopic-like dermatitis: a retrospective study.

Limited information is available describing the features of canine atopic-like dermatitis (ALD) compared with atopic dermatitis (AD). To compare demographic data, disease severity and response to therapy between ALD and AD dogs. Two hundred and fifty-three atopic dogs with intradermal and serum allergen-specific IgE test results were selected retrospectively. Dogs were enrolled into the ALD group if both IgE tests were negative and into the AD group if at least one test was positive. Demographic data, pruritus level and number of body sites affected before and during therapy, in addition to maintenance therapy protocols, were compared between groups. There were 216 (85.38%) dogs in the AD group and 37 (14.62%) in the ALD group. The soft-coated wheaten terrier, American Staffordshire terrier, English bulldog and Labrador retriever were over-represented in the AD group. No significant differences between the groups were noted regarding the other demographic variables evaluated. There were no differences in the mean pruritus scores and number of affected body sites at the first visit or during treatment. Furthermore, no significant differences between the groups were noted for the maintenance treatment scores and reduction of pruritus level and number of body sites affected during treatment. The soft-coated wheaten terrier, American Staffordshire terrier, English bulldog and Labrador retriever were over-represented in the AD group. No significant differences in the other demographic data and clinical features were noted between dogs with ALD and AD in the present study.

SML0417 from Saussurea lappa ameliorates asthma features in murine allergic asthma model

BackgroundThe root of Saussurea lappa has traditionally been used as an ingredient in the treatment of asthma, rheumatism, abdominal pain, anorexia, nausea, and other conditions. Extracts of Saussurea lappa were reported to alleviate house dust mite‐induced atopic‐like dermatitis in Nc/Nga mice, and sesquiterpene lactones were isolated.METHODSTo elucidate whether SML0417, a sesquiterpene lactone has beneficial effects on allergic asthma, anti‐asthma effects were studied using female Balb/c mice and rat RBL‐2H3 mast cells. Antigen‐induced degranulation was measured in vitro by measuring β‐hexosaminidase activity. A murine ovalbumin‐induced allergic asthma model was used to test the in vivo efficacy of SML0417.RESULTSAntigen‐induced degranulation was inhibited by SML0417. Sensitization and challenge of ovalbumin induced allergic asthma responses. Histologic studies showed administration of SML0417 reduced inflammatory signs and mucin production in lungs. Administration of SML0417 decreased numbers of inflammatory cells, especially eosinophils, and reduced the expression and secretion of Th2 cytokines, including IL‐4 and IL‐13, in lung tissues and bronchoalveolar lavage fluid.CONCLUSIONThe present findings provide evidence that SML0417 has a potential therapeutic use in allergic asthma.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Anti‐allergic effect of elecampane camphor from Saussurea lappa in ovalbumin‐induced asthma model

BackgroundIn Oriental countries, the root of Saussurea lappa is used to treat asthma, rheumatism, and other conditions. Extracts of Saussurea lappa were reported to alleviate house dust mite‐induced atopic‐like dermatitis in Nc/Nga mice, and sesquiterpene lactones were isolated.METHODSTo elucidate whether elecampane camphor, a constuent of Saussurea lappa extract has beneficial effects on allergic asthma, anti‐asthma effects were studied using female Balb/c mice and rat RBL‐2H3 mast cells. Antigen‐induced degranulation was measured in vitro by measuring β‐hexosaminidase activity. A murine ovalbumin‐induced allergic asthma model was used to test the in vivo efficacy of the elecampane camphor.RESULTSAntigen‐induced degranulation was inhibited by the elecampane camphor. Sensitization and challenge of ovalbumin induced allergic asthma responses. Administration of elecampane camphor decreased numbers of inflammatory cells, especially eosinophils, and reduced the expression and secretion of Th2 cytokines, including IL‐4 and IL‐13, in lung tissues and bronchoalveolar lavage fluid. Histologic studies showed administration of elecampane camphor reduced inflammatory signs and mucin production in lungs.CONCLUSIONThe findings provide evidence that elecampane camphor has a potential use as anti‐allergic therapeutics.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Epiligulyl oxide from Saussurea lappa inhibited allergic asthma using in vivo and in vitro experiments

BackgroundThe root of Saussurea lappa is used in Asian traditional medicine to treat asthma, rheumatism, and other conditions. Extracts of Saussurea lappa were reported to alleviate house dust mite‐induced atopic‐like dermatitis in Nc/Nga mice, and sesquiterpene lactones were isolated. To elucidate whether epiligulyl oxide, a sesquiterpene lactone has beneficial effects on allergic asthma, anti‐asthma effects were studied using female Balb/c mice and rat RBL‐2H3 mast cellsMETHODSAntigen‐induced degranulation was measured in vitro by measuring β‐hexosaminidase activity. A murine ovalbumin‐induced allergic asthma model was used to test the in vivo efficacy of epiligulyl oxide.RESULTSAntigen‐induced degranulation was inhibited by epiligulyl oxide. Potency Sensitization and challenge of ovalbumin induced allergic asthma responses. Administration of epiligulyl oxide decreased numbers of inflammatory cells, especially eosinophils, and reduced the expression and secretion of Th2 cytokines, including IL‐4 and IL‐13, in lung tissues and bronchoalveolar lavage fluid. Histologic studies showed administration of epiligulyl oxide reduced inflammatory signs and mucin production in lungs.CONCLUSIONThese findings provide evidence that the epiligulyl oxide has potential use as anti‐asthma therapeutics.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Anti-allergic effects of sesquiterpene lactones from Saussurea costus (Falc.) Lipsch. determined using in vivo and in vitro experiments

Ethnopharmacological relevanceSaussurea costus (Falc.) Lipsch. root has been used in Asian traditional medicine for the treatment of asthma, rheumatism, and other conditions. S. costus extracts were shown to alleviate house dust mite-induced atopic-like dermatitis in Nc/Nga mice; besides, sesquiterpene lactones were isolated from S. costus extracts. Aims of the studyWe aimed to investigate the effects of sesquiterpene lactones (alantolactone, costunolide, and dehydrocostuslactone) in allergic asthma using female Balb/c mice and rat RBL-2H3 mast cells. Materials and methodsAntigen-induced degranulation was assessed by measuring β-hexosaminidase activity in vitro. In addition, a murine ovalbumin-induced allergic asthma model was used to test the in vivo efficacy of sesquiterpene lactones. ResultsSesquiterpene lactones inhibited antigen-induced degranulation, wherein dehydrocostuslactone > costunolide > alantolactone in potency. Administration of sesquiterpene lactones decreased the number of immune cells, particularly eosinophils, and reduced the expression and secretion of Th2 cytokines (IL-4 and IL-13) in the bronchoalveolar lavage fluid and lung tissues of mice with ovalbumin-induced allergic asthma. Histological studies showed that sesquiterpene lactones reduced inflammation and mucin production in the lungs. Similar to the in vitro study, dehydrocostuslactone showed the highest potency, followed by costunolide and alantolactone. ConclusionThese findings provide evidence that sesquiterpene lactones might be potential anti-allergic therapeutics.

Oral administration of Lactococcus chungangensis inhibits 2,4-dinitrochlorobenzene-induced atopic-like dermatitis in NC/Nga mice

Interest is increasing in the potentially beneficial role of probiotics in the prevention and treatment of atopic diseases. In this study, we investigated the protective effects of Lactococcus chungangensis CAU 28T against atopic dermatitis using murine macrophage RAW 264.7 cells, human keratinocyte HaCaT cells, human mast cell line HMC-1 cells, and a 2,4-dinitrochlorobenzene-induced atopic dermatitis model (NC/Nga mice). The results showed that L. chungangensis CAU 28T exhibited potent antiinflammatory activity by inhibiting the production of the proinflammatory mediators nitric oxide and prostaglandin E2 in lipopolysaccharide-stimulated RAW 264.7 cells. Treatment with L. chungangensis CAU 28T reduced the release of β-hexosaminidase and histamine in HMC-1 cells stimulated with mast cell activator compound 48/80. In addition, the back skin and ears of NC/Nga mice exhibited reduced histological manifestations of atopic skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration. Oral administration of L. chungangensis CAU 28T suppressed the production of IL-4, IL-5, IL-12, IFN-γ, tumor necrosis factor-α, and thymus- and activation-regulated chemokine (TARC) in skin lesions, indicating that it strongly drives the local immune system with efficacy comparable to that of tacrolimus, a topical immunomodulatory drug used for the treatment of atopic dermatitis. The findings indicate that L. chungangensis CAU 28T could be a novel probiotic candidate for controlling the symptoms of atopic dermatitis.

Tryptase and protease-activated receptor-2 stimulate scratching behavior in a murine model of ovalbumin-induced atopic-like dermatitis.

The aim of the current study was to investigate the involvement of tryptase and protease-activated receptor-2 (PAR2) in the pathogenesis of itch using a recently developed murine model of atopic dermatitis (AD) elicited by epicutaneous sensitization with ovalbumin (OVA). We also examined whether tacrolimus exerts an antipruritic effect. Epicutaneous sensitization of BALB/c mice with OVA led to a significant increase in the number of scratches. Notably, PAR2 mRNA and protein levels as well as cutaneous levels of tryptase were significantly enhanced in epicutaneously sensitized mice. Pretreatment with the protease inhibitor, leupeptin, PAR2 antibody, and tacrolimus significantly reduced the number of degranulated mast cells and tryptase content, and consequently alleviated scratching behavior. Cetirizine (10mg/kg) exerted a significant inhibitory effect on the scratching behavior of mice, but did not affect the number of degranulated mast cells and induction of tryptase. Our results collectively suggest that tryptase and PAR2 are involved in OVA allergy-induced scratching behavior.

Increased itching sensation depends on an increase in the dorsal root ganglia IL-31 receptor A (IL-31RA) expression in mice with atopic-like dermatitis

While itching and scratching are important factors in the development of atopic dermatitis (AD), the mechanisms that underlie these phenomena are poorly understood. Cohousing with skin-lesioned NC/Nga mice, an animal model of AD, gradually increased itch-associated scratching behavior (LLS) counts in several strains mice. On the other hands, repeated dose of interleukin-31 (IL-31) gradually increased LLS counts due to increasing of dorsal root ganglia (DRG) IL-31 receptor A (IL-31RA) expression in mice.We investigated the relationship between the LLS counts and the expression of IL-31 and IL-31RA mRNA in the skin and DRG in mice. The LLS counts were significantly increased in NC/Nga and BALB/c mice after 3, 7 and 14 days cohoused with skin-lesioned NC/Nga mice, in a duration-dependent manner. Cohousing with skin-lesioned NC/Nga mice significantly increased the expression of mRNA for cutaneous IL-31 and DRG IL-31RA compared with these levels in non-cohoused NC/Nga and BALB/c mice, while DRG IL-31 mRNA was not observed. Increased LLS counts were closely correlated with increased DRG IL-31RA mRNA expression, but not with cutaneous IL-31 mRNA, in NC/Nga and BALB/c mice. Moreover, these phenomena were also observed in W/W v and Scid mice after 2 weeks of cohousing with skin-lesioned NC/Nga mice. DRG IL-31RA expression of CNV-NC/Nga mice were significant higher than those of SPF-NC/Nga mice. A single dose of IL-31 significantly increased LLS counts more clearly in CNV-NS/Nga than SPF-NC/Nga mice. These results suggest that IL-31-induced LLS is enhanced by DRG IL-31RA expression in mice, and cohoused induced itching is regulated by DRG IL-31RA expression as in the case of itching induced by repeated administration of IL-31.

Review: The role of antibodies, autoantigens and food allergens in canine atopic dermatitis.

Canine atopic dermatitis (AD) is considered to be an immunoglobulinE (IgE)-mediated hypersensitivity response to environmental allergens. The role of other antibody isotypes and nonenvironmental allergens in disease pathogenesis remains unclear. The objective of this review is to provide an update on advances in the understanding of the relevance of specific antibody isotypes, autoallergens and nonenvironmental allergens in the pathogenesis of canine AD. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed. Where necessary, older articles were included for background information. Neither total nor allergen-specific IgE necessarily correlates with clinical disease in canine AD. Some dogs exhibit clinical signs that are indistinguishable from AD but have no demonstrable allergen-specific IgE (atopic-like dermatitis). Allergen-specific immunoglobulinG may be demonstrated in canine AD, but there is no evidence that this isotype plays a role in disease development. Although humans with AD may develop serum IgE against autoallergens, this finding has not been substantiated in the dog. In contrast, adverse food reactions are frequently co-associated with AD in the dog. Ingestion of food and environmental allergens may trigger exacerbations of AD. Determination of the role of IgE in the pathogenesis of canine AD still requires clarification. Clinical trials and research studies must distinguish atopic dogs with allergen-specific IgE orskin test reactivity from those without. There is no convincing evidence demonstrating a pathogenic role for either allergen-specific immunoglobulinG or autoallergens in canine AD, but food items may be triggers for disease flares in certain individuals.

Food allergens inducing a lymphocyte-mediated immunological reaction in canine atopic-like dermatitis.

Canine atopic-like dermatitis (ALD) is suspected to be associated with food allergies, particularly those mediated by lymphocytes. In this study, 54 cases were included as ALD dogs, based on the negative IgE test results. In the dogs, the percentage of activated cells in helper-T lymphocytes was measured by flow cytometry using cultured peripheral lymphocytes under food allergen stimulation. We observed that 49 of the 54 ALD dogs (90.7%) had positive lymphocyte reactions against one or more food allergens. The most common food allergen was soybean, showing positive results in 21 dogs (42.9%), while the allergen to cause the lowest number of reactions was catfish (only 5 dogs, 10.2%). These results may be useful in considering elimination diets for ALD dogs.