Background
Farm‐derived dust samples have been screened for bacteria with potential allergo‐protective properties. Among those was Staphylococcus sciuri W620 (S. sciuri W620), which we tested with ...regard to its protective capacities in murine models of allergic airway inflammation.
Methods
We employed two protocols of acute airway inflammation in mice administering either ovalbumin (OVA) or house dust mite extract (HDM) for sensitization. Mechanistic studies on the activation of innate immune responses to S. sciuri W620 were carried out using human primary monocytic dendritic cells (moDC) and co‐culture with autologous T cells.
Results
The allergo‐protective properties of S. sciuri W620 were proven in a TH2‐driven OVA model as well as in a mixed TH1/TH2 phenotype HDM model as demonstrated by abrogation of eosinophils and neutrophils in the airways after intranasal treatment. In the HDM model, lymph node cell TH1/TH2 signature cytokines were decreased in parallel. Studies on human moDC revealed an activation of TLR2 and NOD2 receptors and initiation of DC maturation following incubation with S. sciuri W620. Cytokine expression analyses after exposure to S. sciuri W620 showed a lack of IL‐12 production in moDC due to missing transcription of the IL‐12p35 mRNA. However, such DC selectively supported TH1 cytokine release by co‐cultured T cells.
Conclusion and clinical relevance
Our proof‐of‐concept experiments verify the screening system of farm‐derived dust samples as suitable to elucidate new candidates for allergo‐protection. S. sciuri W620 was shown to possess preventive properties on airway inflammation providing the basis for further mechanistic studies and potential clinical implication.
Summary
Background
Clinical studies indicate that maternal exposure to probiotic bacteria may protect from the development of allergic disease later in life.
Objective
The purpose of this study was ...to analyse the effects of a perinatal Lactobacillus rhamnosus GG (LGG) supplementation on the development of allergic disorders in offspring.
Methods
Female BALB/c mice received intragastric LGG every other day before conception, during pregnancy and lactation (perinatal supplementation group) or before conception and during pregnancy only (prenatal supplementation group). Cytokine expression of placental tissues was examined. Offspring of LGG‐supplemented and sham‐exposed mothers were sensitized to Ovalbumin (OVA), followed by aerosol allergen challenges. Development of experimental asthma was assessed by bronchoalveolar lavage analysis, lung histology and lung function measurement. Cytokine production of splenic mononuclear cells was analysed following in vitro stimulation.
Results
Intestinal colonization with LGG was observed in mother mice only, but not in the offspring. However, a reduced expression of TNF‐α, IFN‐γ, IL‐5 as well as IL‐10 was observed in mice derived from perinatally LGG‐supplemented mothers, whereas IL‐13 and IL‐4 expression remained unchanged. Moreover, in offspring of prenatally or perinatally LGG‐supplemented mothers allergic airway and peribronchial inflammation as well as goblet cell hyperplasia were significantly reduced as compared with mice derived from non‐supplemented mothers. In contrast, airway hyperresponsiveness to methacholine was not affected. Exposure to LGG during pregnancy only shifted the placental cytokine expression pattern with a markedly increased TNF‐α level.
Conclusion
Our data suggest that LGG may exert beneficial effects on the development of experimental allergic asthma, when applied in a very early phase of life. Immunological effects are, at least in parts, mediated via the placenta, probably by induction of pro‐inflammatory cell signals.
Summary
Background
Oral supplementation with probiotic bacteria can protect against the development of allergic and inflammatory diseases.
Objective
The aim of this study was to investigate potential ...immunomodulatory and allergy‐protective effects of processed Lactobacillus rhamnosus GG (LGG)‐derived supernatants early in life in neonatal mice.
Methods
In vitro, RAW264.7 mouse macrophages were stimulated with viable LGG, LGG‐derived supernatants, prepared from different growth phases, and different size fractions thereof, and pro‐ and anti‐inflammatory cytokine production was analysed. Supernatant fractions were also treated with protease, DNAse or carbohydrate‐digesting enzymes to define the nature of immunomodulatory components. In vivo, neonatal Balb/c mice were orally supplemented with differentially processed LGG supernatants. Starting at 4 weeks of age, a protocol of ovalbumin‐induced acute allergic airway inflammation was applied and protective effects of processed LGG supernatants were assessed.
Results
Incubation of RAW264.7 cells with LGG‐derived supernatants significantly increased TNFα and IL‐10 production. These effects were not restricted to a particular molecular size fraction. Treatment with protease, but not with DNAse or carbohydrate‐digesting enzymes, completely abolished the immunomodulatory activities. Incubation of TLR/NOD‐transfected cells with LGG‐derived supernatants revealed that recognition and signalling of bioactive components is mediated by TLR2 and NOD2. In vivo supplementation of newborn mice with processed LGG‐derived supernatants resulted in pronounced protective effects on the allergic inflammatory response as reflected by reduced eosinophil numbers, modified T helper cell cytokine production, significantly less lung inflammation and reduced goblet cell numbers in comparison with sham‐treated controls.
Conclusion
LGG‐derived supernatants exert immunomodulatory activities, and neonatal administration of specifically processed supernatants may provide an alternative to viable probiotics in reducing allergic inflammatory responses.
Multiple water-in-oil-in-water (W/O/W) emulsions are of major interest as potential skin delivery systems for water-soluble drugs like oligonucleotides due to their distinct encapsulation properties. ...However, multiple emulsions are highly sensitive in terms of variations of the individual components. The presence of osmotic active ingredients in the inner water phase is crucial for the generation of stable multiple emulsions. In order to stabilize the emulsions the influence of NaCl, MgSO
4, glucose and glycine and two cellulose derivatives was investigated. Briefly, multiple W/O/W emulsions using Span 80 as a lipophilic emulsifier and different hydrophilic emulsifiers (PEG-40/50 stearate, steareth-20 and polysorbate 80) were prepared. Stability of the emulsions was analyzed over a period of time using rheological measurements, droplet size observations and conductivity analysis.
In this study we show that additives strongly influence the properties stability of multiple emulsions. By increasing the concentration of the osmotic active ingredients, smaller multiple droplets are formed and the viscosity is significantly increased. The thickening agents resulted in a slightly improved stability.
The most promising emulsions were chosen and further evaluated for their suitability and compatibility to incorporate a DNAzyme oligonucleotide as active pharmaceutical ingredient.
Summary
Overall asthmatic symptoms can be controlled with diverse therapeutic agents. However, certain symptomatic individuals remain at risk for serious morbidity and mortality, which prompts the ...identification of novel therapeutic targets and treatment strategies. Thus, using an adjuvant‐free T helper type 2 (Th2) murine model, we have deciphered the role of interleukin (IL)‐1 signalling during allergic airway inflammation (AAI). Because functional IL‐1β depends on inflammasome activation we first studied asthmatic manifestations in specific inflammasome‐deficient NACHT, LRR and PYD domains‐containing protein 3 (NLRP3−/−) and apoptosis‐associated speck‐like protein containing a caspase recruitment domain (ASC−/−) and IL‐1 receptor type 1−/− (IL‐1R1−/−) mice on the BALB/c background. To verify the onset of disease we assessed cellular infiltration in the bronchial regions, lung pathology, airway hyperresponsiveness and ovalbumin (OVA)‐specific immune responses. In the absence of NLRP3 inflammasome‐mediated IL‐1β release all symptoms of AAI were reduced, except OVA‐specific immunoglobulin levels. To address whether manipulating IL‐1 signalling reduced asthmatic development, we administered the IL‐1R antagonist anakinra (Kineret®) during critical immunological time‐points: sensitization or challenge. Amelioration of asthmatic symptoms was only observed when anakinra was administered during OVA challenge. Our findings indicate that blocking IL‐1 signalling could be a potential complementary therapy for allergic airway inflammation.
Summary
Introduction
The most widely used protocol for the induction of experimental allergic airway inflammation in mice involves sensitization by intraperitoneal (i.p.) injections of the antigen ...ovalbumin (OVA) used in conjunction with the adjuvant aluminium hydroxide (alum). Although adjuvants are frequently used, there are questions regarding the necessity of alum for murine asthma studies due to the non‐physiological nature of this chemical.
Objective
The objective of this study was to compare experimental asthma phenotypes between adjuvant and adjuvant‐free protocols of murine allergic airway inflammation in an attempt to develop a standardized alternative to adjuvant use.
Method
An adjuvant‐free OVA model of experimental asthma was investigated in BALB/c mice using i.p. or subcutaneous (s.c.) sensitization routes. For the s.c. sensitization, β‐galactosidase (β‐gal) was also tested as an antigen. In addition, OVA adjuvant and adjuvant‐free sensitization protocols were compared in BALB/c and C57BL/6 mice. Open‐field testing was performed to assess the effect of alum on mouse behaviour.
Results
Comparison of adjuvant vs. adjuvant‐free and i.p. vs. s.c. protocols revealed that both adjuvant use and route of antigen application significantly influenced OVA‐specific antibody production. Comparison of adjuvant and adjuvant‐free protocols in this study clearly demonstrated the non‐requirement of alum for the induction of acute allergic airway inflammation, as both protocols induce a similar disease phenotype. BALB/c mice were significantly more susceptible than C57BL/6 mice to sensitization. Using the improved s.c. adjuvant‐free protocol, it was demonstrated that alternative antigens such as β‐gal can also be utilized. Behavioural studies indicated severe distress in mice treated with alum.
Conclusion
The OVA s.c. adjuvant‐free protocol used in this study generates a phenotype comparable to the benchmark adjuvant protocol widely used in the literature. The adjuvant‐free alternative avoids the added complication of non‐physiological adjuvants that may interfere with asthma treatment or prevention strategies.
To cite this article: Renz H, Conrad M, Brand S, Teich R, Garn H, Pfefferle PI. Allergic diseases, gene–environment interactions. Allergy 2011; 66 (Suppl. 95): 10–12.
Allergic asthma develops in part ...from dysregulation of the innate and adaptive immune functions, particularly an imbalance in the Th2‐driven adaptive immune response. This dysregulation is the result of complex interactions between genes and environment. These interactions occur both pre‐ and postnatally, providing opportunities for early interventions in immunological programming.
Summary
Background
Bronchial asthma is characterized by chronic airway inflammation and airway remodelling which occurs in both proximal and distal airways. These changes are associated with ...development of airway hyper‐responsiveness and airflow limitation.
Objective
This study was aimed to analyse whether chronic inhalative allergen challenges in mice lead to morphological and physiological changes comparable with this phenotype.
Methods
For this purpose, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed by aerosol allergen challenges on 2 consecutive days per week for 12 weeks.
Results
In chronically challenged mice, tissue inflammation in proximal as well as distal airways was observed with a predominance of lymphocytes within the cellular infiltrate. In contrast, inflammation in the airway lumen decreased over time. These changes were associated by a shift in bronchoalveolar lavage–cytokine levels from IL‐4, IL‐5 and TNF‐α production (during the acute phase) towards markedly increased levels of TGF‐β during the chronic phase. Goblet cell hyperplasia and subepithelial fibrosis occurred throughout the airway tree. In terms of lung function, chronically challenged mice developed persistent bronchial hyper‐responsiveness and progressive airflow limitation. Six weeks after OVA aerosol discontinuation, airway inflammation still persisted although lung function was normalized.
Conclusion
These data indicate that our model of chronic aerosol allergen challenges leads to a phenotype of experimental asthma with participation of distal airways and persistence of inflammation thereby resembling many morphological and physiological aspects of human bronchial asthma.
A promising approach to reduce the impact of influenza is the use of an attenuated, live virus as a vaccine. Using reverse genetics, we generated a mutant of strain A/WSN/33 with a modified cleavage ...site within its hemagglutinin, which depends on proteolytic activation by elastase. Unlike the wild-type, which requires trypsin, this mutant is strictly dependent on elastase. Both viruses grow equally well in cell culture. In contrast to the lethal wild-type virus, the mutant is entirely attenuated in mice. At a dose of 10(5) plaque-forming units, it induced complete protection against lethal challenge. This approach allows the conversion of any epidemic strain into a genetically homologous attenuated virus.
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