Sex-related differences in the initiation of allergic rhinitis in mice

Sex differences in a murine model of asthma are time and tissue compartment dependent

CONCLUSION

Sexual dimorphism in lung inflammation is both time and tissue compartment dependent. Spatiotemporal variability in sex differences in a murine model of asthma must be accounted for when planning experiments to model the sex bias in allergic inflammation.

The Prevalence, Clinical Picture, and Triggers of Allergic Rhinitis in Saudi Population: A Systematic Review and Meta-Analysis

Objective

To summarize the current evidence regarding the prevalence of Allergic rhinitis (AR) and its symptoms, triggers, and impact on the quality of life of the Saudi population.

Methods

A Computerized Search in MEDLINE via PubMed, MEDLINE Core database, Scopus, and Web of Science was conducted using relevant keywords. A two-stage screening process, data extraction, and quality assessment were conducted by four independent reviewers. Comprehensive Meta-analysis was used for all statistical analyses (CMA; USA: version 3.3.070).

Results

Sixteen articles (n= 31,990 patients) were included. The overall estimated prevalence of AR was 21.2%, 95% CI (12.8-33.1%). Males had a higher prevalence of AR than females (31.7% vs 27.1%), although the difference was not significant (OR=1.24, 95% CI: 0.78-1.953; p=0.356). Children and adolescents exhibited a lower prevalence of AR than adults (13.7% vs 31.1%). Urban AR prevalence was much greater than rural (38.4% vs 13.0%). Asthma, atopic dermatitis, and eczema are all associated with AR. The most common signs and symptoms of AR were headache 33.9%, watery discharge 28.6%, sneezing 24.6%, itchy nose, runny nose 22.2%, nasal obstruction or congestion 22.0%, loss of smell 21.9%, and wheezing 17.2%. The most prevalent triggers of AR were perfume 36.8%, dust 27.3%, air conditioning 23.4%, weather or temperature changes 17.8%, air pollution 14.5%, drugs or chemicals 13.8%, tobacco 10.8%, atopy 10.3%, and insects 10.2%.

Conclusion

The overall prevalence of AR in Saudi Arabia is 21.2%. The prevalence of AR was comparable in both males and females. However, it was higher in adults than in children and adolescents, and in urban areas than rural areas. Asthma, atopic dermatitis, and eczema co-occurrence with AR are common. AR has a negative impact on the quality of life of the patients in the form of interference with daily activities, sleep problems, difficulty of breath, and school absenteeism.

Hormonal Effects on Asthma, Rhinitis, and Eczema

Hormones significantly influence the pathogenesis of asthma, rhinitis, and eczema. This review aims to summarize relevant clinical considerations for practicing allergists and immunologists. The first section reviews the effects of sex hormones: estrogen, progesterone, and testosterone. The second concerns insulin production in the context of type 1 and type 2 diabetes. The third concludes with a discussion of thyroid and adrenal pathology in relationship to asthma, rhinitis, and eczema.

Sex, Cells, and Asthma

There are marked sex differences in asthma prevalence and severity. Sex hormones play a central role in these sex biases and directly interact with multiple key cells involved in the pathogenesis of asthma. Here we review the known effects of estrogen, progesterone, and testosterone on airway epithelial cells, airway smooth muscle cells, the mononuclear phagocyte system, innate lymphoid cells, eosinophils, mast cells, T cells, and B cells, all in the context of asthma. Furthermore, we explore unresolved clinical questions, such as the role of sex hormones in the link between asthma and obesity.

Factors Contributing to Sex Differences in Mice Inhaling Aspergillus fumigatus

Aspergillus fumigatus is a respiratory fungal pathogen and an allergen, commonly detected in flooded indoor environments and agricultural settings. Previous studies in Balb/c mice showed that repeated inhalation of live and dry A. fumigatus spores, without any adjuvant, elevated allergic immune response and airway remodeling. Sex-specific differences can influence host-pathogen interactions and allergic-asthma related outcomes. However, the effect of host sex on immune response, in the context of A. fumigatus exposure, remains unknown. In this study, we quantified the multivariate and univariate immune response of C57BL/6J mice to live, dry airborne A. fumigatus spores. Our results corroborate previous results in Balb/c mice that repeated inhalation of live A. fumigatus spores is sufficient to induce mucus production and inflammation by day 3 post last challenge, and antibody titers and collagen production by day 28 post-challenge. Principal Component Analysis (PCA) showed that females exhibited significantly higher levels of immune components than males did. Taken together, our data indicate that host-sex is an important factor in shaping the immune response against A. fumigatus, and must be considered when modeling disease in animals, in designing diagnostics and therapeutics for A. fumigatus-associated diseases or while drafting evidence-based guidelines for safe mold levels.

Impact of Androgens on Inflammation-Related Lipid Mediator Biosynthesis in Innate Immune Cells

Rheumatoid arthritis, asthma, allergic rhinitis and many other disorders related to an aberrant immune response have a higher incidence and severity in women than in men. Emerging evidences from scientific studies indicate that the activity of the immune system is superior in females and that androgens may act as “immunosuppressive” molecules with inhibitory effects on inflammatory reactions. Among the multiple factors that contribute to the inflammatory response, lipid mediators (LM), produced from polyunsaturated fatty acids, represent a class of bioactive small molecules with pivotal roles in the onset, maintenance and resolution of inflammation. LM encompass pro-inflammatory eicosanoids and specialized pro-resolving mediators (SPM) that coexist in a tightly regulated balance necessary for the return to homeostasis. Innate immune cells including neutrophils, monocytes and macrophages possess high capacities to generate distinct LM. In the last decades it became more and more evident that sex represents an important variable in the regulation of inflammation where sex hormones play crucial roles. Recent findings showed that the biosynthesis of inflammation-related LM is sex-biased and that androgens impact LM formation with consequences not only for pathophysiology but also for pharmacotherapy. Here, we review the modulation of the inflammatory response by sex and androgens with a specific focus on LM pathways. In particular, we highlight the impact of androgens on the biosynthetic pathway of inflammation-related eicosanoids in innate immune cells.

Matters of life and death: How estrogen and estrogen receptor binding to the immunoglobulin heavy chain locus may influence outcomes of infection, allergy, and autoimmune disease

Sex hormones are best known for their influences on reproduction, but they also have profound influences on the immune response. Examples of sex-specific differences include: (i) the relatively poor control of influenza virus infections in males compared to females, (ii) allergic asthma, an IgE-associated hypersensitivity reaction that is exacerbated in adolescent females compared to males, and (iii) systemic lupus erythematosus, a life-threatening autoimmune disease with a 9:1 female:male bias. Here we consider how estrogen and estrogen receptor α (ERα) may influence the immune response by modifying class switch recombination (CSR) and immunoglobulin expression patterns. We focus on ERα binding to enhancers (Eμ and the 3' regulatory region) and switch sites (Sµ and Sε) in the immunoglobulin heavy chain locus. Our preliminary data from ChIP-seq analyses of purified, activated B cells show estrogen-mediated changes in the positioning of ERα binding within and near Sµ and Sε. In the presence of estrogen, ERα is bound not only to estrogen response elements (ERE), but also to adenosine-cytidine (AC)-repeats and poly adenosine (poly A) sequences, in some cases within constant region gene introns. We propose that by binding these sites, estrogen and ERα directly participate in the DNA loop formation required for CSR. We further suggest that estrogen regulates immunoglobulin expression patterns and can thereby influence life-and-death outcomes of infection, hypersensitivity, and autoimmune disease.

The Roles of Sex Hormones in the Course of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by T helper 2 cell (Th2)-shifted abnormal immunity, skin barrier impairment, and pruritus. The prevalence of AD in childhood is slightly higher in boys than in girls; after puberty, the sexual difference is reversed. The female preponderance in all generations exists in intrinsic AD with enhanced Th1 activity and nickel allergy, lacking increased serum IgE or filaggrin mutation. AD is often deteriorated before menstruation. We review the effects of sex hormones on immune responses and skin permeability barrier and propose possible hypotheses for the above phenomena. After puberty, the immune responses of patients are remarkably influenced by sex hormones. Estrogen and progesterone enhance the activities of Th2/regulatory T cell (Treg) but suppress Th1/Th17. Androgens suppress Th1/Th2/Th17 and induce Treg. The skin permeability barrier is fortified by estrogen but is impaired by progesterone and androgens. Dehydroepiandrosterone suppresses Th2 but enhances Th1. The amount of steroid sulfatase converting dehydroepiandrosterone sulfate to dehydroepiandrosterone is higher in women than in men, and thus, women might be more susceptible to the influence of dehydroepiandrosterone. The balance of modulatory effects of sex hormones on immune responses and skin barrier might regulate the course of AD.

Allergenicity assessment of Buchanania lanzan protein extract in Balb/c mice

Tree nuts are among "Big Eight" and have been reported globally for causing allergy. Buchanania lanzan (Bl) is one of the major tree nuts consumed by Indian population. However, very little is known about B. lanzan's induced allergic manifestation. Therefore, evaluation of it's allergenic potential was undertaken. Bl-crude protein extract sensitized BALB/c mice sera were used to identify the allergic proteins by it's IgE binding capability. The major IgE binding proteins found with molecular weight of 11, 20, 23, 25, 48, 54, and 65 kDa. Specific IgE, specific IgG1, MCPT-1, PGD₂ and histamine were assessed in mice sera. Enormous amount of mast cell infiltration was noted in different organs. The levels of Th1/Th2 transcription factors GATA-3, SOCS3 and STAT-6 were found upregulated, whereas T-bet was downregulated. Furthermore, elevated Th1/Th2 cytokine responses were observed in mice sera. All together, these reactions developed systemic anaphylaxis upon Bl-CPE challenge in sensitized BALB/c mice. In order to confirm the evidences obtained from the studies carried out in BALB/c, the investigation was extended to human subjects as well. Control subjects and allergic patients were subjected to skin prick test (SPT). Later sera collected from those positive to SPT along with controls were used for IgE immunoblotting. The study evaluated the allergic manifestation associated with Bl, and identified it's proteins attributing Bl-mediated allergy. This work may help in managing tree nuts mediated allergies especially due to Buchanania lanzan sensitization.

Androgen-Induced Immunosuppression

In addition to determining biological sex, sex hormones are known to influence health and disease via regulation of immune cell activities and modulation of target-organ susceptibility to immune-mediated damage. Systemic autoimmune disorders, such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis are more prevalent in females, while cancer shows the opposite pattern. Sex hormones have been repeatedly suggested to play a part in these biases. In this review, we will discuss how androgens and the expression of functional androgen receptor affect immune cells and how this may dampen or alter immune response(s) and affect autoimmune disease incidences and progression.

Phenotypes, Risk Factors, and Mechanisms of Adult-Onset Asthma

Asthma is a heterogeneous disease with many phenotypes, and age at disease onset is an important factor in separating the phenotypes. Genetic factors, atopy, and early respiratory tract infections are well-recognized factors predisposing to childhood-onset asthma. Adult-onset asthma is more often associated with obesity, smoking, depression, or other life-style or environmental factors, even though genetic factors and respiratory tract infections may also play a role in adult-onset disease. Adult-onset asthma is characterized by absence of atopy and is often severe requiring treatment with high dose of inhaled and/or oral steroids. Variety of risk factors and nonatopic nature of adult-onset disease suggest that variety of mechanisms is involved in the disease pathogenesis and that these mechanisms differ from the pathobiology of childhood-onset asthma with prevailing Th2 airway inflammation. Recognition of the mechanisms and mediators that drive the adult-onset disease helps to develop novel strategies for the treatment. The aim of this review was to summarize the current knowledge on the pathogenesis of adult-onset asthma and to concentrate on the mechanisms and mediators involved in establishing adult-onset asthma in response to specific risk factors. We also discuss the involvement of these mechanisms in the currently recognized phenotypes of adult-onset asthma.

A multicenter study of the clinical features of allergic rhinitis in central China

BACKGROUND

Several epidemiological surveys of allergic rhinitis (AR) have been conducted in China. However, the clinical features of AR are still not clear enough. The aim of the current study was to perform a multicenter investigation to evaluate the clinical features of AR in China.

METHODS

A multicenter investigation was performed in 13 allergy centers in central China. A disease-related questionnaire was completed by each patient themselves or with guardian assistance after the diagnosis of AR. The clinical features of AR and allergen profile were analyzed.

RESULTS

Eleven thousand four patients who were diagnosed with AR were recruited in this study. The percentages of classification of AR according to the Allergic Rhinitis and Its Impact on Asthma guidelines were 9.7% intermittent mild (IM), 3.1% persistent mild (PM), 33.9% intermittent moderate-severe (IMS), and 53.3% persistent moderate-severe (PMS). There were 61.6 and 42.2% AR patients who had concomitant ocular or lower respiratory symptoms in clinic. The occurrence of ocular and lower respiratory symptoms was found to be gradually increased from IM, PM, and IMS to PMS. Cold air and temperature change were the two most common factors triggering the nasal symptoms. Dermatophagoides pteronyssinus and Dermatophagoides farinae were the most important allergens of central China.

CONCLUSIONS

This study has contributed to a better understanding of clinical features of AR in China.

Total IgE plasma levels vary according to gender and age in Brazilian patients with allergic rhinitis

OBJECTIVE

Allergic rhinitis is a disease that affects the upper airways and causes inflammation of the nasal mucosa and it is mediated by IgE antibodies produced after sensitization to environmental allergens. Previous reports have indicated that this disease affects males more often than females. The objective of this study was to verify whether total IgE plasma levels vary between genders in patients suffering from allergic rhinitis.

METHODS

A total of 171 adult patients suffering from allergic rhinitis (55 males and 116 females) were enrolled. Total IgE plasma levels were determined using commercial kits, with 140 IU/mL considered as a reference value. The mean total IgE plasma levels were compared according to gender and age.

RESULTS

The mean age of the overall patient group with allergic rhinitis was 38.4 ± 19.0 years and a significant difference in age was observed between genders (males: 32.2 ± 17.8 years; females: 41.4 ± 18.9 years; p=0.0027). Additionally, the mean total IgE plasma levels were higher in males (413.0 ± 143.0 IU/mL) than in females (147.9 ± 98.0 IU/mL) (p<0.0001). These differences persisted even when males and females were stratified by age (up to or older than 20 years of age).

CONCLUSIONS

In conclusion, total IgE plasma levels are higher in young adult males than in females suffering from allergic rhinitis. Evaluating total IgE plasma levels can be useful to identify patients at risk of allergic rhinitis in areas with low industrial pollution.

Efficiency of different decalcification protocols for nasal osseous structures in a rat experimental model of allergic rhinitis, and their effects on epithelial histology: an attempt at standardization

INTRODUCTION

Decalcification of osseous specimens is required for histological analysis; this however may cause tissue damage. In rodent models of allergic rhinitis (AR), epithelial histologic assessment necessitates prior decalcification of the nasal osseous structures. However, respiratory epithelium is highly susceptible to damage, and rat nasal architecture is elaborate and its sectioning is challenging. Nevertheless, decalcification is not standardized in experimental AR. We therefore undertook this task, in order to reduce experimental bias.

METHODS

Six-to-eight week-old Wistar rats underwent an AR protocol. Subsequently, nasal structures were decalcified in the following mediums: (i) formic acid 10% for 5 and 20 days; (ii) formic acid 15% for 5 and 15 days; (iii) Morse Solution for 5 and 20 days and (iv) EDTA for 20 and 40 days. Decalcification efficiency/speed was evaluated via radiographic analysis. Furthermore, specimens were stained with hematoxylin and eosin and assessed for preservation of epithelial features.

RESULTS

Specimens were appropriately decalcified in 5 days in the formic acid-based mediums and in 20 days in EDTA with minimal epithelial damage. EDTA for 40 days had no unacceptable adverse effects; conversely, 15 and/or 20 days in acid-based agents provided no extra benefit for decalcification and were detrimental to the epithelium.

CONCLUSIONS

EDTA treatment for 20 days is appropriate for decalcification of nasal structures in rat models of allergic rhinitis; further incubation preserves epithelial integrity but is not required. When urgency is a factor, formic-acid-based decalcification for 5 days yields acceptable results.

Gender difference in allergic airway remodelling and immunoglobulin production in mouse model of asthma

BACKGROUND AND OBJECTIVE

Epidemiological studies have shown that the prevalence of adult asthma and severe asthma is higher in women. It has also been reported that female mice are more susceptible than males to the development of allergic airway inflammation and airway hyperresponsiveness (AHR). The influence of gender difference in the pathogenesis of severe asthma, especially airway remodelling in an animal model, has been studied rarely. We investigated gender difference in the development of airway remodelling using a long-term antigen-challenged mouse asthma model.

METHODS

Following ovalbumin (OVA)/alum intraperitoneal injection, male or female mice (BALB/c) were challenged with aerosolized 1% OVA on 3 days/week for 5 weeks, and differences in AHR, airway inflammation and airway remodelling between the sexes were investigated.

RESULTS

In OVA-sensitized and OVA-challenged (OVA/OVA) female mice, eosinophils, lymphocytes, T-helper type 2 cytokines and growth factors in bronchoalveolar lavage fluid were increased compared with OVA/OVA male mice. Histological features of airway remodelling were also increased in OVA/OVA female mice. Serum total and OVA-specific immunoglobulin E (IgE) and serum IgA were significantly elevated in OVA/OVA female mice.

CONCLUSIONS

These results indicate that female mice experience more airway remodelling compared with male mice. These results suggest the involvement of sex hormones and gender differences in cellular functions in airway remodelling.

Food-dependent exercise-induced anaphylaxis: is wheat unique?

This review draws comparisons between wheat-dependent exercise-induced anaphylaxis (WDEIA) and other food-dependent exercise-induced anaphylaxis (FDEIAs) and discusses the importance of co-factors in its pathophysiology. FDEIA remains an enigmatic condition since it was first described 30 years ago. The sporadic and unpredictable nature of its reactions has puzzled clinicians and scientists for decades, but recent studies on WDEIA have enlightened us about the pathophysiology of this condition. The identification of defined allergic epitopes such as Tri a 19, α-gliadin, β-gliadin and γ-gliadin in WDEIA enables it to become the perfect model for studying FDEIA, but WDEIA is by no means a unique condition. On a larger scale, FDEIA represents a crucial link between IgE-mediated and anaphylactoid reactions and provides supportive evidence for the concept of 'summation anaphylaxis' and the need to overcome the 'allergen threshold'. Future work should focus on identifying more of the FDEIA epitopes and understanding their distinct molecular properties. The development of a biomarker in order to identify patients susceptible to co-factor influences would be invaluable.

Adjuvants are Key Factors for the Development of Future Vaccines: Lessons from the Finlay Adjuvant Platform

The development of effective vaccines against neglected diseases, especially those associated with poverty and social deprivation, is urgently needed. Modern vaccine technologies and a better understanding of the immune response have provided scientists with the tools for rational and safer design of subunit vaccines. Often, however, subunit vaccines do not elicit strong immune responses, highlighting the need to incorporate better adjuvants; this step therefore becomes a key factor for vaccine development. In this review we outline some key features of modern vaccinology that are linked with the development of better adjuvants. In line with the increased desire to obtain novel adjuvants for future vaccines, the Finlay Adjuvant Platform offers a novel approach for the development of new and effective adjuvants. The Finlay Adjuvants (AFs), AFPL (proteoliposome), and AFCo (cochleate), were initially designed for parenteral and mucosal applications, and constitute potent adjuvants for the induction of Th1 responses against several antigens. This review summarizes the status of the Finlay technology in producing promising adjuvants for unsolved-vaccine diseases including mucosal approaches and therapeutic vaccines. Ideas related to adjuvant classification, adjuvant selection, and their possible influence on innate recognition via multiple toll-like receptors are also discussed.

Offspring IgE responses are influenced by levels of maternal IgG transferred in early life

PROBLEM

Maternal immune responses may interfere with offspring allergy development as maternal immunization may suppress IgE development, while maternal allergy may promote allergy. Therefore, we investigated the effect of two different maternal treatments on airway allergy in female and male offspring.

METHOD OF STUDY

Pregnant mice were immunized (IMM) with ovalbumin (OVA) or immunized and airway-challenged (IMM+AI). At different ages, airway allergy to OVA was induced in offspring by intranasal sensitization.

RESULTS

Maternal IgG1 was found at higher levels in IMM+AI than in IMM offspring. After sensitization, the suppression of OVA-specific IgE and IgG1 was complete in juvenile offspring but waned with age concurrently with maternal IgG1 levels. Cytokine secretion, lung inflammation, and B cell priming were not suppressed although IgE responses were.

CONCLUSIONS

High compared with low levels of maternal IgG1 were associated with lower TH 2 antibody production after adult offspring were re-exposed to OVA. Thus, offspring allergy-related responses appeared to be shaped by maternal antibody levels.

The relationship between atopic dermatitis and indoor environmental factors: a cross-sectional study among Japanese elementary school children

OBJECTIVES

This study aimed to determine that home environmental factors were associated with atopic dermatitis in Japanese elementary school children.

METHODS

In this cross-sectional study, a total of 4,254 children in 12 public elementary schools in Sapporo city in Hokkaido, Japan were examined. Atopic dermatitis was defined using the International Study of Asthma and Allergies in Childhood questionnaire. The questionnaires also contained 14 questions about the child's home environment. To obtain multivariate-adjusted ORs for atopic dermatitis in relation to the home environment, we controlled for possible confounders including gender, school grade, parental history of allergies, number of siblings, and whether the child was firstborn. The study participants were then divided into two groups according to gender, and a stratified analysis was performed to obtain adjusted ORs for atopic dermatitis in relation to the home environment.

RESULTS

The prevalence of atopic dermatitis in our sample was 16.7 %. Using fully adjusted models, the risk factors for atopic dermatitis were found to be the household use of a non-electric heating system without a ventilation duct to the outside (compared to the use of an electric heating system), having visible mould in the house, having a mouldy odour in the house, and condensation on the windowpanes in the house odds ratios (OR 1.25-1.54). In our stratified analysis, having visible mould and having a mouldy odour in the house were relevantly found to be risk factors for boys (OR 1.28-1.64). However, these associations were not found among girls.

CONCLUSIONS

To improve children's health, further study is needed to corroborate the findings.

Time trends of allergic rhinitis and effects of residence on allergic rhinitis in Korea from 1998 through 2007-2009

PURPOSE

Longitudinal changes in the prevalence of self-reported physician-diagnosed allergic rhinitis (AR) in Korea and the association between the prevalence of AR and type of residence area among Korean males and females in 1998, 2001, 2005 and 2007-2009 were evaluated.

METHODS

Age-standardized prevalence was calculated using the Korea National Health and Nutrition Examination Survey (KNHANES) I-IV. Stratified factors of sex, age, and socioeconomic status were adjusted to compare the prevalence of AR in relation to residential area by multiple logistic analysis.

RESULTS

The prevalence of AR increased by tenfolds from 1.2 % in 1998 to 12.0 % in 2007-2009. The trends for prevalence of AR were also statistically significant (p < .05). The age-standardized prevalence of AR among urban females was higher (13.9%) than that in rural females (11.5%). After adjustment for survey years, age, socioeconomic levels and asthma, the odds of AR were higher in urban than rural residents, except for males in 1998.

CONCLUSION

The prevalence of AR in Korea has increased over the past decade, and living in an urban area may be a susceptible factor. For prevention and management of AR, further evaluations of contributing factors and mechanisms underlying differences in AR are needed.

Determinants of experimental allergic responses: interactions between allergen dose, sex and age

The prevalence of allergic diseases is influenced by sex and age. Although mouse models are widely used in allergy research, few experimental studies have examined the interaction effects of sex and age on allergy outcomes. Our aim was to investigate the individual and combined effects of sex and age on allergic sensitization and inflammation in two mouse models: an intraperitoneal (i.p.) and an intranasal (i.n.) sensitization model. We also investigated how the allergen immunization dose interacted with age and sex in the i.p. model. Female and male mice were immunized i.p. or i.n. with ovalbumin when 1, 6 or 20 weeks old. In both models, allergen challenges were performed by i.n. delivery. Serum antibodies, draining lymph node cytokine release and airway inflammatory responses were assessed. In the i.p. model, the antibody and cytokine levels and airway inflammation were highly influenced by immunization dose and age. The responses increased with age when using a low immunization dose, but decreased with age when using a high immunization dose. In the i.n. model, antibody production and airway tissue inflammation increased with age. Female compared with male mice generally developed more pronounced antibody and inflammatory responses. Relative to older mice, juvenile mice had augmented airway inflammation to allergen exposures. The study demonstrates that immunization dose, sex and age are highly influential on allergy outcomes. To better mimic different life stages of human allergic airway disease, murine models, therefore, require careful optimization.

Do low testosterone levels contribute to the pathogenesis of asthma?

Asthma is a chronic inflammatory airway disorder that causes respiratory hypersensitivity and intermittent obstruction. Airway hyperresponsiveness to both specific and nonspecific stimuli is the hallmark of asthma. Although genetic susceptibility and airway inflammation are believed to play fundamental roles, etiology of asthma is unknown. In most cases, the treatment of asthma focuses on control of factors contributing to asthma severity and pharmacologic therapy including bronchodilator and anti-inflammatory agents. The prevalence of reported asthma is greater in prepubertal boys, with a change to a female predominance after puberty. Many epidemiological studies also suggest that women are at increased risk of developing adult-onset asthma and also suffer from more severe disease than men. This strongly suggests an important role for sex hormones in asthma. Previous articles provided us that, testosterone and/or its metabolites maintain the physiological balance of autoimmunity and protective immunity by preserving the number of regulatory cells. Testosterone is an immunosuppressant and is likely to be protective against immunological and inflammatory processes that trigger asthma. We hypothesized that the testosterone or selective androgen receptor modulators would have beneficial effects on asthma and could decrease the risk of asthmatic attacks.

Production of native bispecific antibodies in rabbits

Background

A natural bispecific antibody, which can be produced by exchanging Fab arms of two IgG4 molecules, was first described in allergic patients receiving therapeutic injections with two distinct allergens. However, no information has been published on the production of natural bispecific antibody in animals. Even more important, establishment of an animal model is a useful approach to investigate and characterize the naturally occurring antibody.

Methodology/Principal Findings

We demonstrated that a natural bispecific antibody can also be generated in New Zealand white rabbits by immunization with synthesized conjugates. These antibodies showed bispecificity to the components that were simultaneously used to immunize the animals. We observed a trend in our test animals that female rabbits exhibited stronger bispecific antibody responses than males. The bispecific antibody was monomeric and primarily belonged to immunoglobulin (Ig) G. Moreover, bispecific antibodies were demonstrated by mixing 2 purified monospecific antibodies in vivo and in vitro.

Conclusions/Significance

Our results extend the context of natural bispecific antibodies on the basis of bispecific IgG4, and may provide insights into the exploration of native bispecific antibodies in immunological diseases.

Similar response in male and female B10.RIII mice in a murine model of allergic airway inflammation

BACKGROUND

Several reports have been published on the gender differences associated with allergies in mice.

GOAL

In the present study we investigate the influence of gender on allergy response using a strain of mice, B10.RIII, which is commonly used in the collagen-induced arthritis murine model.

METHODS

Both male and female B10.RIII young mice were immunized with OVA and challenged four times with OVA intranasally. Samples were taken 24 h after the last challenge, and eosinophils in bronchoalveolar lavage (BAL) and parenchyma, Th-2 cytokines in BAL, total and antigen-specific IgE in sera, and antigen-specific T-cell proliferation were measured.

RESULTS

Immunization in both male and female B10.RIII mice with OVA elicited a classical Th2-type response. Results showed no significant differences among male and female mice. Also a high eosinophilia in BAL fluid and parenchyma was produced in both genders without any significant differences. However, the deviation of both parameters was higher in young males compared to young females.

CONCLUSIONS

Gender differences, classically associated with some strains of mice, are not reproducible in B10.RIII mice. Gender differences in murine models of allergic airway inflammation are probably strain-dependent.

Sex Disparity in Food Allergy: Evidence from the PubMed Database

Food allergies are potentially fatal immune-mediated disorders that are growing globally. The relationship between sex and food allergy remains incompletely understood. Here we tested the hypothesis that, should sex influence the clinical response to food allergens, this would be reflected by a sex disparity in published studies of food allergy. We performed a systematic search of the PubMed literature for IgE-mediated allergy to 11 allergenic foods of international regulatory importance. No date restriction was used and only articles in English were considered. Of the 4744 articles retrieved, 591 met the inclusion criteria representing 17528 subjects with food allergies. Whereas among children with food allergies, 64.35% were males and 35.65% were females (male/female ratio, 1.80), among adults 34.82% were males and 65.18% were females (male/female ratio, 0.53). Consequently, these data argue that there is need for further investigation to define the role of sex in the pathogenesis of food allergy.

Prenatal risk factors and occurrence of allergic rhinitis among elementary school children in an urban city

OBJECTIVES

To investigate the incidence and prenatal risk factors for allergic rhinitis among elementary school children in an urban city.

STUDY DESIGN

Risk factor data were collected by questionnaire and direct physical examination. Multiple logistic regression analysis was used to calculate the odds ratios of developing allergic rhinitis among children 6-13 years of age.

METHODS

From January 2006 to December 2006, we enrolled 1368 elementary school children in the study. Sampling was done by a multi-stage clustered-stratified random method to determine the study subject. All the children studied attended 12 elementary schools located in the six districts in Taipei, with two schools in each district. Odds ratios were adjusted for the confounding effects of gender, parity, maternal age at childbirth, maternal education, gestational complications, tobacco smokers in the residence, pets, carpets, molds, and air pollution.

RESULTS

The incidence of allergic rhinitis in the study was 50.1% (685/1368). Factors like gender (p<.001), parity (p<.05), carpets (p<.025), and air pollution (p<.001) increased risk, while the other factors did not (p>.05 for all).

CONCLUSION

Gender, parity, carpets, and air pollution increased the risk of developing allergic rhinitis among elementary school children. Other potential factors such as low birth weight, maternal age at childbirth, parental education, gestational complications, presence of tobacco smokers, and exposure to pets and molds did not significantly increase risk of developing allergic rhinitis.

Gender difference, sex hormones, and immediate type hypersensitivity reactions

Gender differences in the development and prevalence of human diseases have long been recognized. Immense interest grows in the understanding of the role of sex hormones in the homeostasis of immunity. Asthma predominates in boys before puberty and this gender preference reverses after puberty and in adulthood, when adult women tend to have a more severe disease, often recalcitrant to treatment. Atopic eczema in preschool children shows insignificant gender difference or male preponderance in different studies, with more adult females suffering from atopic eczema. The limited data on the prevalence of immediate hypersensitivity to hymenoptera venom show controversial results. Discrepancy exists regarding the gender difference in food allergy, with females reporting significantly more allergic reactions in questionnaire studies. In general, adverse reactions to nonionic iodinated radiocontrast media are more commonly observed in females. The course of allergic diseases varies unpredictably during pregnancy, whereas hormone replacement therapy in postmenopausal women usually has a favorable influence on the course of asthma. Experiments in rodents confirm an effect of estrogens on mast cell activation and allergic sensitization, while progesterone is shown to suppress histamine release but potentiate IgE induction. Dehydroepiandrosterone may antagonize the production of Th2 cytokines but the effect of testosterone and the other androgens remains less defined. Actual data from human studies are lacking.

Neuroendocrine factors alter host defense by modulating immune function

An increasing body of evidence demonstrates that there is bidirectional communication between the neuroendocrine and immune systems. Interaction between these systems results in a variety of outcomes, including the well documented "sickness behavior" elicited by cytokines of the immune system that can enter the brain and activate second messengers that modify neuronal activity. Crosstalk between the neuroendocrine and immune systems can also result in production of factors by the nervous and endocrine systems that alter immune cell function and subsequent modulation of immune responses against infectious agents and other pathogens. Continued exposure to molecules produced by the neuroendocrine system has also been known to increase susceptibility and/or severity of disease. Furthermore, neuroendocrine factors are thought to play a major role in gender-specific differences in development of certain disorders, including autoimmune/inflammatory diseases that have a two to tenfold higher incidence in females compared to males. Neuroendocrine factors can affect immune cells at the level of gene transcription but have also been shown to modify immune cell activity by interacting with intracellular molecules, resulting in modified ability of these cells to mount a potent immune response. In this review, we will consider various effects of the neuroendocrine system and its proteins on specific populations of immune cells and associated responses in host immunity against pathogens. We will further discuss how this modification of immune cell activity by the neuroendocrine system can contribute to susceptibility/severity of disease development.

Maternal testosterone in pregnancy and atopic outcomes in childhood

BACKGROUND

In mice, androgens downregulate Th2 cytokine responses, but whether androgen levels during pregnancy might influence the development of allergy in the offspring has not been studied.

METHODS

In the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort of 14 541 pregnancies, we related maternal blood total testosterone during pregnancy, measured in a subset of the cohort, to allergic outcomes in the offspring, including asthma, hayfever, eczema (n=543) and wheezing (n=532) at 69-81 months, and atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n=386) and blood total immunoglobulin E (IgE; n=314) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders.

RESULTS

Maternal testosterone was negatively associated with total IgE in boys [adjusted geometric mean ratio (GMR), per doubling of testosterone, 0.33 (0.20-0.55), P=0.000038 (n=168)], but not in girls [GMR 1.04 (0.53-2.06), P=0.91 (n=146)], P-value interaction 0.0086. The effect in boys was even stronger in the absence of maternal atopic disease. Testosterone was not associated with skin test positivity or atopic disease in either sex.

CONCLUSIONS

Higher testosterone levels in pregnancy are associated with lower IgE production in boys.

Endocrine disrupters--potential modulators of the immune system and allergic response

Endocrine disrupters (EDs) are environmental pollutants of industrial or agricultural origin (e.g. herbicides, fungicides, insecticides, industrial chemicals) that may influence health of wildlife and human. Endocrine-disrupting effect is obtained by mimicking the action of the steroid hormones and has been associated with several reproductive disorders as well as cancerogenesis both in animals and humans. EDs can also influence synthesis of cytokines, immunoglobulins, and cell mediators as well as immune cell activation and survival. Modulation by EDs of interleukin-4 production, Th1/Th2 balance and IgE production suggest their potential effect on allergic immune responses. The aim of this review was to summarize data indicating a potential effect of EDs exposure on the immune system and allergic responses.

E prostanoid 2 (EP2)/EP4-mediated suppression of antigen-specific human T-cell responses by prostaglandin E2

Prostaglandin E2 (PGE2) is a lipid mediator that displays important immunomodulatory properties, such as polarization of cytokine production by T cells. Recent investigations have revealed that the effect of PGE2 on cytokine production is greatly influenced by external stimuli; however, it is unclear whether PGE2 plays a significant role in major histocompatibility complex-mediated antigen-specific T-cell responses via binding to one of four subtypes of E prostanoid (EP) receptor alone or in combination. In the present study, we sought to determine the effect of PGE2 on antigen-specific CD4+ T-cell responses in humans, especially in terms of receptor specificity. We used purified protein derivative (PPD) and Cry j 1 as T helper type 1 (Th1) and Th2-inducing antigens, respectively. We generated several different Cry j 1- and PPD-specific T-cell lines (TCLs). PGE2 significantly and dose-dependently inhibited the proliferation and subsequent production of interleukin-4 by Cry j 1-specific TCLs and of interferon-gamma by PPD-specific TCLs upon antigen stimulation. Administration of EP2 receptor agonist and EP4 receptor agonist suppressed these responses in an adenylate cyclase-dependent manner, while EP1 and EP3 receptor agonists did not. Messenger RNA for EP2, EP3 and EP4, but not EP1, receptors were detected in Cry j 1- and PPD-specific TCLs, and no differences in EP receptor expression were observed between them. Furthermore, PGE2 and EP2 receptor agonist significantly inhibited interleukin-5 and interferon-gamma production by peripheral blood mononuclear cells in response to Cry j 1 and PPD stimulation, respectively. These results suggest that PGE2 suppresses both Th1- and Th2-polarized antigen-specific human T-cell responses via a cAMP-dependent EP2/EP4-mediated pathway.

Genistein enhancement of respiratory allergen trimellitic anhydride-induced IgE production by adult B6C3F1 mice following in utero and postnatal exposure

The objective of the present study was to determine if exposure to the phytoestrogen genistein (GEN) during immune development had any effects on the production of IgE by adult mice following dermal treatment with trimellitic anhydride (TMA), a respiratory allergen. B6C3F1 mice were exposed to GEN either by feeding at 500 ppm or by gavage (20 mg/kg) for varied periods from gestation day (GD) 14 to postnatal day (PND) 84. In utero exposure to GEN by feeding increased the production of IgE at PND 84 in male mice but not in female mice. In male mice, continuous exposure to GEN postnatally diminished the in utero exposure-induced enhancement in serum total IgE production. However, continuous exposure to GEN from GD 14 to PND 84 was required to increase serum total IgE production in female mice. In utero exposure to GEN by gavage increased the production of IgE at PND 84 in female mice but not in male mice when the mice were maintained on the NIH-07 rodent diet in which a medium level of phytoestrogens was present. The enhancement in IgE production after GEN exposure in females but not in males was associated with decreases in the percentages of CD4(+)CD25(+) T suppressor cells, and increases in the natural killer (NK) cell activity, the basal splenocyte proliferation, the expression of CD86 by B cells, and the production of IL-2 and IL-4. Overall, the results demonstrated that GEN differentially modulated the developing immune system in male and female mice, and that more IgE was produced upon exposure to TMA in the adult.

Local therapy with CpG motifs in a murine model of allergic airway inflammation in IFN-beta knock-out mice

Background

CpG oligodeoxynucleotides (CpG-ODN) are capable of inducing high amounts of type I IFNs with many immunomodulatory properties. Furthermore, type-I IFNs have been proposed to play a key role in mediating effects of CpG-ODN. The precise role of IFN-β in the immunomodulatory effects of CpG-ODN is not known.

Objective

Here, we aimed to elucidate the role of IFN-β in the anti-allergic effect of CpG motifs.

Methods

We assessed the immune response in OVA-primed/OVA-challenged IFN-β knockout (-/-) mice compared to wild type (WT) control, after intranasal and systemic treatment with synthetic CpG motifs.

Results

Vaccination with CpG-ODN reduced the number of cells in airways of OVA-sensitized WT but not IFN-β-/- mice. Although airway eosinophilia was reduced in both treated groups, they were significantly higher in IFN-β^-/- mice. Other inflammatory cells, such as lymphocytes and macrophages were enhanced in airways by CpG treatment in IFN-β-/- mice. The ratio of IFN-γ/IL-4 cytokines in airways was significantly skewed to a Th1 response in WT compared to IFN-β^-/- group. In contrast, IL-4 and IgE were reduced with no differences between groups. Ag-specific T-cell proliferation, Th1-cytokines such as IFN-γ, IL-2 and also IL-12 were significantly lower in IFN-β-/- mice. Surprisingly, we discovered that intranasal treatment of mice with CpG-ODN results in mild synovitis particularly in IFN-β-/- mice.

Conclusion

Our results indicate that induction of Th1 response by therapy with CpG-ODN is only slightly and partially dependent on IFN-β, while IFN-β is not an absolute requirement for suppression of airway eosinophilia and IgE. Furthermore, our finding of mild synovitis is a warning for possible negative effects of CpG-ODN vaccination.

Immunosuppressive effect of restraint stress on the initiation of allergic rhinitis in mice

BACKGROUND

Exposure to acute stressors modulates both innate and acquired immune function. However, little is known about whether stress has the potential to modulate the pathogenesis of allergic rhinitis.

OBJECTIVES

To determine the effects of acute restraint stress on the initiation of allergic rhinitis in a murine model.

METHODS

CBA/J mice were repeatedly intranasally sensitized with phospholipase A2 (PLA2) from honeybee venom without adjuvant. Restraint stress was applied using uniform cylinders once a week for a continuous 8-hour period, on five occasions in total. Production of PLA2-specific antibodies and degree of nasal and blood eosinophilia were compared between stressed and control mice.

RESULTS

Repeated intranasal sensitization with PLA2 induced PLA2-specific IgE and marked eosinophilia in both the nose and blood in CBA/J mice. Exposure to restraint stress significantly inhibited production of PLA2-specific IgE, IgG1 and IgG2a. Conversely, the stress exerted no significant effect on eosinophilia.

CONCLUSIONS

Exposure to acute restraint stress inhibits antigen-specific antibody production, but not local or systemic eosinophilia. The results of this study suggest that acute stress has the potential to modulate the initiation of allergic rhinitis.

Gender differences in human immunodeficiency virus type 1-specific CD8 responses in the reproductive tract and colon following nasal peptide priming and modified vaccinia virus Ankara boosting

Induction of mucosal anti-human immunodeficiency virus type 1 (HIV-1) T-cell responses in males and females will be important for the development of a successful HIV-1 vaccine. An HIV-1 envelope peptide, DNA plasmid, and recombinant modified vaccinia virus Ankara (rMVA) expressing the H-2D(d)-restricted cytotoxic T lymphocyte P18 epitope were used as immunogens to test for their ability to prime and boost anti-HIV-1 T-cell responses at mucosal and systemic sites in BALB/c mice. We found of all prime-boost combinations tested, an HIV-1 Env peptide subunit mucosal prime followed by systemic (intradermal) boosting with rMVA yielded the maximal induction of gamma interferon (IFN-gamma) spot-forming cells in the female genital tract and colon. However, this mucosal prime-systemic rMVA boost regimen was minimally immunogenic for the induction of genital, colon, or lung anti-HIV-1 T-cell responses in male mice. We determined that a mucosal Env subunit immunization could optimally prime an rMVA boost in female but not male mice, as determined by the magnitude of antigen-specific IFN-gamma responses in the reproductive tracts, colon, and lung. Defective mucosal priming in male mice could not be overcome by multiple mucosal immunizations. However, rMVA priming followed by an rMVA boost was the optimal prime-boost strategy for male mice as determined by the magnitude of antigen-specific IFN-gamma responses in the reproductive tract and lung. Thus, prime-boost immunization strategies able to induce mucosal antigen-specific IFN-gamma responses were identified for male and female mice. Understanding the cellular and molecular basis of gender-determined immune responses will be important for optimizing induction of anti-HIV-1 mucosal immune responses in both males and females.

Immunoglobulin E- (IgE) and non-IgE-mediated reactions in the pathogenesis of atopic eczema/dermatitis syndrome (AEDS)

AEDS is a chronic, relapsing, highly pruritic inflammatory skin disease that commonly begins in childhood. Two forms of this disorder exist, i.e. an allergic (extrinsic) form and a nonallergic (intrinsic) form. There are clear genetic, humoral and cellular differences between the allergic and nonallergic forms of AEDS. The allergic variants express local IgE production in affected tissue and both allergic and nonallergic triggers play a major role in the expression of disease. The role of allergens is very important in the immunopathogenesis of AEDS. Nonimmunological triggers play a secondary modulatory role often hampering treatment effort and optimal response to therapeutic efforts.

Roles of FcgammaRIIB in nasal eosinophilia and IgE production in murine allergic rhinitis

The low-affinity IgG Fc receptor, FcgammaRIIB, displays inhibitory potential in experimental models such as autoimmune diseases. However, whether this receptor is involved in the onset of allergic diseases remains unknown. This study examines the role of FcgammaRIIB in the initiation of allergic rhinitis in mice. Repeated intranasal sensitization with Schistosoma mansoni egg antigen (SEA) induced SEA-specific IgE and marked nasal eosinophilia in high-responder BALB/c mice. FcgammaRIIB gene-deficient (-/-) BALB/c mice displayed severe eosinophilia compared with that of wild-type counterparts. However, FcgammaRIIB -/- mice conversely produced less SEA-specific IgE. The production of interleukin (IL)-4 but not of IL-5 or IFN-gamma by nasal mononuclear cells was also decreased in FcgammaRIIB -/- mice, suggesting that the exacerbation of nasal eosinophila in FcgammaRIIB -/- mice is independent of the local IL-5 levels. The findings in low responder C57BL/6 mice were similar. In addition, nasal eosinophilia in FcgammaRIIB -/- mice passively sensitized with SEA was exacerbated, and conversely, specific IgE production was inhibited after a nasal challenge. These results suggest that FcgammaRIIB plays a regulatory role in the initiation of allergic rhinitis that is independent of either mouse strain or type of sensitization.

Allergic and nonallergic forms of atopic diseases

Atopic dermatitis, allergic rhinitis, and asthma are atopic diseases that develop on a complex genetic background, the so-called atopic diathesis. Although they target different organs, in most patients they are characterized by the presence of elevated total serum IgE levels. However, a subgroup of atopic patients exhibits normal IgE levels and mechanisms contributing to the so-called "intrinsic" or "nonallergic form" have been the matter of intensive research work in the last years. Because of the rapid advancements in the research field of atopic diseases, it now becomes possible for the first time to delineate a new disease classification of allergic and nonallergic subtypes of atopic diseases, thereby bringing hope to the clinician for a more specific treatment approach for each subgroup of these patients.

Less sensitivity for late airway inflammation in males than females in BALB/c mice

Several studies have investigated allergic airway inflammation, a T helper 2 (Th2)-type immune response, using a mouse model of asthma. At present, however, no reports have described sex differences in the sensitivity of late airway inflammation (LAI). The LAI induced by ovalbumin in adult BALB/c mice was compared in males and females or sham-operated males and castrated males. The males showed less severe bronchial-bronchiolar inflammation with infiltration of eosinophils and lymphocytes and lower content of such cells in bronchoalveolar fluid than the females. Moreover, interleukin-4 (IL-4) mRNA expression levels in splenic cells were lower in the males than in the females. Castrated males performed like the females. Moreover, when compared with the sham-operated males, the castrated males showed lower testosterone levels in the blood. The present results suggest that less sensitivity for LAI in the males may be because of the decreased Th2 cell responses compared with the females. Moreover the testosterone, at least in part, may be responsible for the decreased Th2 cell responses in males in vivo.