Vitamin A and D in allergy: from experimental animal models and cellular studies to human disease

Nutrition in chronic inflammatory conditions: Bypassing the mucosal block for micronutrients

Nutritional Immunity is one of the most ancient innate immune responses, during which the body can restrict nutrients availability to pathogens and restricts their uptake by the gut mucosa (mucosal block). Though this can be a beneficial strategy during infection, it also is associated with non-communicable diseases-where the pathogen is missing; leading to increased morbidity and mortality as micronutritional uptake and distribution in the body is hindered. Here, we discuss the acute immune response in respect to nutrients, the opposing nutritional demands of regulatory and inflammatory cells and particularly focus on some nutrients linked with inflammation such as iron, vitamins A, Bs, C, and other antioxidants. We propose that while the absorption of certain micronutrients is hindered during inflammation, the dietary lymph path remains available. As such, several clinical trials investigated the role of the lymphatic system during protein absorption, following a ketogenic diet and an increased intake of antioxidants, vitamins, and minerals, in reducing inflammation and ameliorating disease.

Regulation of Dendritic Cell Functions by Vitamins as Promising Therapeutic Strategy for Immune System Disorders

A functional immune system is crucial for a healthy life, protecting from infections, tumors, or autoimmune disorders; these are accomplished by the interaction between various immune cells. Nourishment, particularly micronutrients, are very important components in the immune system balance, therefore this review emphasizes the vitamins (D, E, A, C) and Dendritic cells' subsets due to vitamins' roles in immune processes, especially on dendritic cells' functions, maturation, and cytokine production. Current studies reveal significant benefits related to vitamins, including vitamin E, which can contribute to the control of dendritic cells' function and maturation. Furthermore, vitamin D plays an immunoregulatory and anti-inflammatory role in the immune system. Metabolite of vitamin A which is called retinoic acid leads to T cells' differentiation to T helper 1 or T helper 17, so low levels of this vitamin exacerbate the menace of infectious diseases, and vitamin C has anti-oxidant effects on dendritic cells and modulate their activation and differentiation program. Additionally, the correlation between the amount of vitamin and the occurrence or progression of allergic diseases and autoimmunity disorders is discussed according to the results of previous studies.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Evaluating the effects of vitamin D Level on airway obstruction in two asthma endotypes in humans and in two mouse models with different intake of vitamin D during early-life

Introduction

Asthma is primarily divided into two categories: type 2 (T2-high) and non-type 2 (T2-low). A relationship between asthma severity and vitamin D deficiency has been identified, but its impact on each asthma endotype remains unknown.

Methods

We clinically examined the influence of vitamin D on patients with T2-high (n = 60) or T2-low asthma (n = 36) compared with controls (n = 40). Serum 25(OH)D levels, inflammatory cytokines and spirometry were measured. Mouse models were then used to further analyze the effects of vitamin D on both asthmatic endotypes. BALB/c mice were fed with vitamin D-deficient (LVD), -sufficient (NVD), or -supplemented diets (HVD) throughout lactation and offspring followed the same diet after weaning. Offspring were sensitized/challenged with ovalbumin (OVA) to establish "T2-high" asthma or OVA combined with ozone exposure (OVA + ozone) to induce "T2-low" asthma. Spirometry and serum, bronchoalveolar lavage fluid (BALF), and lung tissues were analyzed.

Results

Serum 25(OH)D levels were decreased in asthmatic patients compared with controls. Patients with vitamin D deficiency (Lo) had varying degrees of elevation of the pro-inflammatory cytokines IL-5, IL-6, and IL-17A, decreased expression of the anti-inflammatory cytokine IL-10, and altered forced expiratory volume in the first second as a percentage of predicted value (FEV₁%pred) in both asthmatic endotypes. Vitamin D status had a stronger correlation with FEV₁%pred in T2-low asthma than T2-high asthma, and 25(OH)D level was only positively linked to maximal mid-expiratory flow as a percentage of predicted value (MMEF%pred) in the T2-low group. Inflammation, hyperresponsiveness, and airway resistance (R_L) was increased in both asthma models compared with controls while vitamin D deficiency further increased airway inflammation and airway obstruction. These findings were particularly prominent in T2-low asthma.

Discussion

The potential function and mechanisms of vitamin D and both asthma endotypes should be studied individually, and further analysis of the potential signaling pathways involved with vitamin D on T2-low asthma is warranted.

Lack of iron, zinc, and vitamins as a contributor to the etiology of atopic diseases

Micronutritional deficiencies are common in atopic children suffering from atopic dermatitis, food allergy, rhinitis, and asthma. A lack of iron, in particular, may impact immune activation with prolonged deficiencies of iron, zinc, vitamin A, and vitamin D associated with a Th2 signature, maturation of macrophages and dendritic cells (DCs), and the generation of IgE antibodies. In contrast, the sufficiency of these micronutrients establishes immune resilience, promotion of regulatory cells, and tolerance induction. As micronutritional deficiencies mimic an infection, the body's innate response is to limit access to these nutrients and also impede their dietary uptake. Here, we summarize our current understanding of the physiological function of iron, zinc, and vitamins A and D in relation to immune cells and the clinical consequences of deficiencies in these important nutrients, especially in the perinatal period. Improved dietary uptake of iron is achieved by vitamin C, vitamin A, and whey compounds, whereas zinc bioavailability improves through citrates and proteins. The addition of oil is essential for the dietary uptake of beta-carotene and vitamin D. As for vitamin D, the major source comes via sun exposure and only a small amount is consumed via diet, which should be factored into clinical nutritional studies. We summarize the prevalence of micronutritional deficiencies of iron, zinc, and vitamins in the pediatric population as well as nutritional intervention studies on atopic diseases with whole food, food components, and micronutrients. Dietary uptake via the lymphatic route seems promising and is associated with a lower atopy risk and symptom amelioration. This review provides useful information for clinical studies and concludes/emphasizes that a healthy, varied diet containing dairy products, fish, nuts, fruits, and vegetables as well as supplementing foods or supplementation with micronutrients as needed is essential to combat the atopic march.

Discussion on the Clinical Course of Adverse Effects after COVID-19 Vaccination: A Retrospective Analysis of Case Series in an Outpatient Department

BACKGROUND

A total of 8,303 individuals (4.3%) with adverse reactions (n=191,860) after vaccination developed serious conditions or died. Such health developments could cause people not vaccinated yet or waiting for a booster shot to become fearful of the vaccination.

METHODS

The 3-month (July-September 2021) clinical data of 41 patients from the family medicine department of a single medical center were analyzed retrospectively to determine risk factors and to investigate the clinical course to identify the cause of symptoms in detail.

RESULTS

A significant number of older adults aged over 50 years reported experiencing general weakness (P=0.026) but fewer incidences of fever than patients aged 50 years or younger (P=0.011). Eighteen of the 41 patients were requested to visit more than twice or consult a specialist. In 14 patients, the symptoms were explained by other medical causes.

CONCLUSION

The primary physician has a pivotal role in thoroughly evaluating patients who complain of adverse effects after vaccination, considering the broad multitude of symptoms and medical conditions presented. To thoroughly evaluate and appropriately advise patients with adverse reactions to their chosen vaccine, taking detailed medical history and nutritional counseling are required to identify possible underlying causes, resolve symptoms, and educate them on self-care and regarding vaccines.

IgA-producing B cells in lung homeostasis and disease

Immunoglobulin A (IgA) is the most abundant Ig in mucosae where it plays key roles in host defense against pathogens and in mucosal immunoregulation. Whereas intense research has established the different roles of secretory IgA in the gut, its function has been much less studied in the lung. This review will first summarize the state-of-the-art knowledge on the distribution and phenotype of IgA⁺ B cells in the human lung in both homeostasis and disease. Second, it will analyze the studies looking at cellular and molecular mechanisms of homing and priming of IgA⁺ B cells in the lung, notably following immunization. Lastly, published data on observations related to IgA and IgA⁺ B cells in lung and airway disease such as asthma, cystic fibrosis, idiopathic pulmonary fibrosis, or chronic rhinosinusitis, will be discussed. Collectively it provides the state-of-the-art of our current understanding of the biology of IgA-producing cells in the airways and identifies gaps that future research should address in order to improve mucosal protection against lung infections and chronic inflammatory diseases.

Association of vitamin A supplementation with immune-related allergic diseases: A meta-analysis

BACKGROUND

Allergic diseases are type I hypersensitivity reactions mediated by various allergens. The most common allergic diseases include allergic rhinitis, allergic asthma, allergic dermatitis, and allergic conjunctivitis. The incidence of allergic diseases has been increasing in the recent past, and allergen avoidance and adoption of desensitization treatment can significantly decrease the incidence of allergic diseases. Previous studies have explored the association between vitamin A supplementation and allergic diseases; however, the results are inconsistency. The aim of the present study was to evaluate the association between vitamin A supplementation and allergic diseases, with a focus on atopy and wheezing.

METHODS

Articles reporting randomized controlled trials (RCTs) on the association of vitamin A supplementation and allergic diseases were retrieved from PubMed, Embase, Web of science, and China National Knowledge Infrastructure database from inception of to November 15, 2021. STATA 12.0 software was used for meta-analysis, sensitivity analysis and analysis of publication bias.

RESULTS

Seven studies comprising 2201 participants met the inclusion criteria and were included in the meta-analysis. The findings showed that vitamin A supplementation was associated with increased risk of atopy in young females compared with the placebo [RR = 1.70, 95% confidence interval (1.20, 2.41), P = 0.171, I 2 = 43.4% fixed effect model]. The frequency of delayed atopy among adults was associated with vitamin A supplementation (MD = 0.46, 95% CI = 0.04, 0.88). Analysis showed no significant association between vitamin A supplementation with incidence of wheezing in children [RR = 1.40, 95% CI (0.49, 3.98), P = 0.018, I 2 = 82.1% random effect model]. Sensitivity and publication bias analysis showed that each individual study did not affect the combined results and there was no significant publication bias among the studies.

CONCLUSION

The findings showed that vitamin A supplementation is associated with increased risk of atopy but no correlation was observed with the incidence of wheezing. The results of this meta-analysis provide evidence for effective management of fibrosis. More studies should be conducted to verify the results.

Epithelial barrier hypothesis: Effect of the external exposome on the microbiome and epithelial barriers in allergic disease

Environmental exposure plays a major role in the development of allergic diseases. The exposome can be classified into internal (e.g., aging, hormones, and metabolic processes), specific external (e.g., chemical pollutants or lifestyle factors), and general external (e.g., broader socioeconomic and psychological contexts) domains, all of which are interrelated. All the factors we are exposed to, from the moment of conception to death, are part of the external exposome. Several hundreds of thousands of new chemicals have been introduced in modern life without our having a full understanding of their toxic health effects and ways to mitigate these effects. Climate change, air pollution, microplastics, tobacco smoke, changes and loss of biodiversity, alterations in dietary habits, and the microbiome due to modernization, urbanization, and globalization constitute our surrounding environment and external exposome. Some of these factors disrupt the epithelial barriers of the skin and mucosal surfaces, and these disruptions have been linked in the last few decades to the increasing prevalence and severity of allergic and inflammatory diseases such as atopic dermatitis, food allergy, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, and asthma. The epithelial barrier hypothesis provides a mechanistic explanation of how these factors can explain the rapid increase in allergic and autoimmune diseases. In this review, we discuss factors affecting the planet's health in the context of the 'epithelial barrier hypothesis,' including climate change, pollution, changes and loss of biodiversity, and emphasize the changes in the external exposome in the last few decades and their effects on allergic diseases. In addition, the roles of increased dietary fatty acid consumption and environmental substances (detergents, airborne pollen, ozone, microplastics, nanoparticles, and tobacco) affecting epithelial barriers are discussed. Considering the emerging data from recent studies, we suggest stringent governmental regulations, global policy adjustments, patient education, and the establishment of individualized control measures to mitigate environmental threats and decrease allergic disease.

Safety Data in Patients with Autoimmune Diseases during Treatment with High Doses of Vitamin D3 According to the “Coimbra Protocol”

Background: In 2013, the group of Cicero Coimbra, Brazil, reported the clinical efficacy of high doses of vitamin D3 in patients suffering from autoimmune skin disorders (“Coimbra protocol”, CP). However, hypercalcemia and the subsequent impaired renal function may be major concerns raised against this protocol. Methods: We report for the first time for a broad spectrum of autoimmune diseases in 319 patients (mean age (±SD) 43.3 ± 14.6 years, 65.5% female, 34.5% male) safety data for high doses of orally applied vitamin D3 (treatment period: up to 3.5 years) accompanied by a strict low-calcium diet and regular daily fluid intake of at least 2.5 L. Results: Mean vitamin D3 dose was 35,291 ± 21,791 IU per day. The measurement of more than 6100 single relevant laboratory parameters showed all mean values (±SD) within the normal range for total serum calcium (2.4 ± 0.1 mmol/L), serum creatinine (0.8 ± 0.2 mg/dL), serum creatinine associated estimated GFR (92.5 ± 17.3 mL/min), serum cystatin C (0.88 ± 0.19 mg/L), serum TSH (1.8 ± 1 mIU/L), and for 24 h urinary calcium secretion (6.9 ± 3.3 mmol/24 h). We found a very weak relationship between the dosage of oral vitamin D3 and the subsequent calcium levels, both in serum and in urinary excretion over 24 h, respectively. Conclusions: Our data show the reliable safety of the CP in autoimmune patients under appropriate supervision by experienced physicians.

Role of the dietary components in food allergy: A comprehensive review

Currently, the increasing incidence of food allergy is considered a major public health and food safety concern. Importantly, food-induced anaphylaxis is an acute, life-threatening, systemic reaction with varied clinical presentations and severity that results from the release of mediators from mast cells and basophils. Many factors are blamed for the increasing incidence of food allergy, including hygiene, microbiota (composition and diversity), inopportune complementary foods (a high-fat diet), and increasing processed food consumption. Studies have shown that different food components, including lipids, sugars, polyphenols, and vitamins, can modify the immunostimulating properties of allergenic proteins and change their bioavailability. Understanding the role of the food components in allergy might improve diagnosis, treatment, and prevention of food allergy. This review considers the role of the dietary components, including lipids, sugars, polyphenols, and vitamins, in the development of food allergy as well as results of mechanistic investigations in in vivo and in vitro models.

Ameliorating Atopy by Compensating Micronutritional Deficiencies in Immune Cells: A Double-Blind Placebo-Controlled Pilot Study

BACKGROUND

Functional iron deficiency facilitates allergy development and amplifies the symptom burden in people experiencing allergies. Previously we selectively delivered micronutrients to immune cells with β-lactoglobulin as carrier (holoBLG), resulting in immune resilience and allergy prevention.

OBJECTIVE

The clinical efficacy of a food for special medical purposes-lozenge containing β-lactoglobulin with iron, polyphenols, retinoic acid, and zinc (holoBLG lozenge) was assessed in allergic women.

METHODS

In a randomized, double-blind, placebo-controlled pilot study, grass- and/or birch pollen-allergic women (n = 51) were given holoBLG or placebo lozenges over 6 months. Before and after dietary supplementation, participants were nasally challenged and the blood was analyzed for immune and iron parameters. Daily symptoms, medications, pollen concentrations, and well-being were recorded by an electronic health application.

RESULTS

Total nasal symptom score after nasal provocations improved by 42% in the holoBLG group versus 13% in the placebo group. The combined symptom medication score during the birch peak and entire season as well as the entire grass pollen season improved in allergic subjects supplemented with the holoBLG lozenge by 45%, 31%, and 40%, respectively, compared with the placebo arm. Participants ingesting the holoBLG lozenge had improved iron status with increased hematocrit values, decreased red cell distribution width, and higher iron levels in circulating CD14⁺ cells compared with the placebo group.

CONCLUSIONS

Targeted micronutrition with the holoBLG lozenge seemed to be effective in elevating the labile iron levels in immune cells and reducing the symptom burden in allergic women in this pilot study. The underlying allergen-independent mechanism provides evidence that dietary nutritional supplementation of the immune system is one of the ways to combat atopy.

Pollutants enhance IgE sensitization in the gut via local alteration of vitamin D-metabolizing enzymes

Mechanisms linking ingested pollutants to increased incidence of allergy are poorly understood. We report that mice exposed to low doses of cadmium develop higher IgE responses following oral allergen sensitization and more severe allergic symptoms upon allergen challenge. The environmentally relevant doses of this pollutant also induced oxidative/inflammatory responses in the gut of SPF, but not germ-free mice. Interestingly, the increased IgE responses correlated with stimulation of the vitamin D3-metabolizing enzymes CYP27B1 and CYP24A1 in the gut and increased luminal levels of oxidized vitamin D3 metabolites that are not ligands of the vitamin D receptor. Inhibition of CYP27B1 and CYP24A1 via oral administration of pharmacological inhibitors reduced IgE responses induced in mice orally exposed to cadmium. Our findings identify local alteration of vitamin D signaling as a new mechanism for induction of IgE responses by environmental pollutants. They also identify vitamin D3-metabolizing enzymes as therapeutic targets for the treatment of allergy.

Oral nanomedicine for modulating immunity, intestinal barrier functions, and gut microbiome

The gastrointestinal tract (GIT) affects not only local diseases in the GIT but also various systemic diseases. Factors that can affect the health and disease of both GIT and the human body include 1) the mucosal immune system composed of the gut-associated lymphoid tissues and the lamina propria, 2) the intestinal barrier composed of mucus and intestinal epithelium, and 3) the gut microbiota. Selective delivery of drugs, including antigens, immune-modulators, intestinal barrier enhancers, and gut-microbiome manipulators, has shown promising results for oral vaccines, immune tolerance, treatment of inflammatory bowel diseases, and other systemic diseases, including cancer. However, physicochemical and biological barriers of the GIT present significant challenges for successful translation. With the advances of novel nanomaterials, oral nanomedicine has emerged as an attractive option to not only overcome these barriers but also to selectively deliver drugs to the target sites in GIT. In this review, we discuss the GIT factors and physicochemical and biological barriers in the GIT. Furthermore, we present the recent progress of oral nanomedicine for oral vaccines, immune tolerance, and anti-inflammation therapies. We also discuss recent advances in oral nanomedicine designed to fortify the intestinal barrier functions and modulate the gut microbiota and microbial metabolites. Finally, we opine about the future directions of oral nano-immunotherapy.

Dysregulated retinoic acid signaling in airway smooth muscle cells in asthma

Vitamin A deficiency has been shown to exacerbate allergic asthma. Previous studies have postulated that retinoic acid (RA), an active metabolite of vitamin A and high-affinity ligand for RA receptor (RAR), is reduced in airway inflammatory condition and contributes to multiple features of asthma including airway hyperresponsiveness and excessive accumulation of airway smooth muscle (ASM) cells. In this study, we directly quantified RA and examined the molecular basis for reduced RA levels and RA-mediated signaling in lungs and ASM cells obtained from asthmatic donors and in lungs from allergen-challenged mice. Levels of RA and retinol were significantly lower in lung tissues from asthmatic donors and house dust mite (HDM)-challenged mice compared to non-asthmatic human lungs and PBS-challenged mice, respectively. Quantification of mRNA and protein expression revealed dysregulation in the first step of RA biosynthesis consistent with reduced RA including decreased protein expression of retinol dehydrogenase (RDH)-10 and increased protein expression of RDH11 and dehydrogenase/reductase (DHRS)-4 in asthmatic lung. Proteomic profiling of non-asthmatic and asthmatic lungs also showed significant changes in the protein expression of AP-1 targets consistent with increased AP-1 activity. Further, basal RA levels and RA biosynthetic capabilities were decreased in asthmatic human ASM cells. Treatment of human ASM cells with all-trans RA (ATRA) or the RARγ-specific agonist (CD1530) resulted in the inhibition of mitogen-induced cell proliferation and AP-1-dependent transcription. These data suggest that RA metabolism is decreased in asthmatic lung and that enhancing RAR signaling using ATRA or RARγ agonists may mitigate airway remodeling associated with asthma.

Treatment of chronic airway diseases using nutraceuticals: Mechanistic insight

Respiratory diseases, both acute and chronic, are reported to be the leading cause of morbidity and mortality, affecting millions of people globally, leading to high socio-economic burden for the society in the recent decades. Chronic inflammation and decline in lung function are the common symptoms of respiratory diseases. The current treatment strategies revolve around using appropriate anti-inflammatory agents and bronchodilators. A range of anti-inflammatory agents and bronchodilators are currently available in the market; however, the usage of such medications is limited due to the potential for various adverse effects. To cope with this issue, researchers have been exploring various novel, alternative therapeutic strategies that are safe and effective to treat respiratory diseases. Several studies have been reported on the possible links between food and food-derived products in combating various chronic inflammatory diseases. Nutraceuticals are examples of such food-derived products which are gaining much interest in terms of its usage for the well-being and better human health. As a consequence, intensive research is currently aimed at identifying novel nutraceuticals, and there is an emerging notion that nutraceuticals can have a positive impact in various respiratory diseases. In this review, we discuss the efficacy of nutraceuticals in altering the various cellular and molecular mechanisms involved in mitigating the symptoms of respiratory diseases.

Retinoic acid improves baseline barrier function and attenuates TNF-α-induced barrier leak in human bronchial epithelial cell culture model, 16HBE 14o

Retinoic acid (RA) has been shown to improve epithelial and endothelial barrier function and development and even suppress damage inflicted by inflammation on these barriers through regulating immune cell activity. This paper thus sought to determine whether RA could improve baseline barrier function and attenuate TNF-α-induced barrier leak in the human bronchial epithelial cell culture model, 16HBE14o- (16HBE). We show for the first time that RA increases baseline barrier function of these cell layers indicated by an 89% increase in transepithelial electrical resistance (TER) and 22% decrease in ¹⁴C-mannitol flux. A simultaneous, RA-induced 70% increase in claudin-4 attests to RA affecting the tight junctional (TJ) complex itself. RA was also effective in alleviating TNF-α-induced 16HBE barrier leak, attenuating 60% of the TNF-α-induced leak to ¹⁴C-mannitol and 80% of the leak to ¹⁴C-inulin. Interleukin-6-induced barrier leak was also reduced by RA. Treatment of 16HBE cell layers with TNF-α resulted in dramatic decrease in immunostaining for occludin and claudin-4, as well as a downward “band-shift” in occludin Western immunoblots. The presence of RA partially reversed TNF-α’s effects on these select TJ proteins. Lastly, RA completely abrogated the TNF-α-induced increase in ERK-1,2 phosphorylation without significantly decreasing the TNF-driven increase in total ERK-1,2. This study suggests RA could be effective as a prophylactic agent in minimizing airway barrier leak and as a therapeutic in preventing leak triggered by inflammatory cascades. Given the growing literature suggesting a “cytokine storm” may be related to COVID-19 morbidity, RA may be a useful adjuvant for use with anti-viral therapies.

High dose vitamin D3 empowers effects of subcutaneous immunotherapy in a grass pollen-driven mouse model of asthma

Allergen-specific immunotherapy (AIT) has the potential to provide long-term protection against allergic diseases. However, efficacy of AIT is suboptimal, while application of high doses allergen has safety concerns. The use of adjuvants, like 1,25(OH)2VitD3 (VitD3), can improve efficacy of AIT. We have previously shown that low dose VitD3 can enhance suppression of airway inflammation, but not airway hyperresponsiveness in a grass pollen (GP)-subcutaneous immunotherapy (SCIT) mouse model of allergic asthma. We here aim to determine the optimal dose and formulation of VitD3 for the GP SCIT. GP-sensitized BALBc/ByJ mice received three SCIT injections of VitD3-GP (30, 100, and 300 ng or placebo). Separately, synthetic lipids, SAINT, was added to the VitD3-GP-SCIT formulation (300 nmol) and control groups. Subsequently, mice were challenged with intranasal GP, and airway hyperresponsiveness, GP-specific IgE, -IgG1, and -IgG2a, ear-swelling responses (ESR), eosinophils in broncho-alveolar lavage fluid and lung were measured. VitD3 supplementation of GP-SCIT dose-dependently induced significantly enhanced suppression of spIgE, inflammation and hyperresponsiveness, while neutralizing capacity was improved and ESR were reduced. Addition of VitD3 further decreased Th2 cytokine responses and innate cytokines to allergens in lung tissue by GP-SCIT. However, addition of synthetic lipids to the allergen/VitD3 mixes had no additional effect on VitD3-GP-SCIT. We find a clear, dose dependent effect of VitD3 on GP-SCIT-mediated suppression of allergic inflammation and airway hyperresponsiveness. In contrast, addition of synthetic lipids to the allergen/VitD3 mix had no therapeutic effect. These studies underscore the relevance of VitD3 as an adjuvant to improve clinical efficacy of SCIT treatment regimens.

Dietary Vitamin D Supplementation Is Ineffective in Preventing Murine Cow's Milk Allergy, Irrespective of the Presence of Nondigestible Oligosaccharides

INTRODUCTION

Cow's milk allergy (CMA) is one of the most common food allergies especially early in life. A mixture of nondigestible short-chain galacto-oligosaccharides, long-chain fructo-oligosaccharides, and pectin-derived acidic-oligosaccharides (GFA) may reduce allergy development and allergic symptoms in murine CMA. Recently, vitamin D (VitD) has been suggested to have beneficial effects in reducing allergy as well.

OBJECTIVE

In this study, the immune modulatory effect on allergy prevention using the combination of GFA and VitD was investigated.

METHODS

Female C3H/HeOuJ mice were fed a control or GFA-containing diet with depleted, standard (1,000 IU/kg), or supplemented (5,000 IU/kg) VitD content for 2 weeks before and during whey sensitization (n = 10-15). Mice were sensitized 5 times intragastrically with PBS as a control, whey as cow's milk allergen, and/or cholera toxin as adjuvant on a weekly interval. One week after the last sensitization, mice were intradermally challenged in both ear pinnae and orally with whey, subsequently the acute allergic skin response and shock symptoms were measured. After 18 h, terminal blood samples, mesenteric lymph nodes, and spleens were collected. Whey-specific immunoglobulin (Ig) E and IgG1 levels were measured by means of ELISA. T cell subsets and dendritic cells (DCs) were studied using flow cytometry.

RESULTS

Additional VitD supplementation did not lower the allergic symptoms compared to the standard VitD diet. CMA mice fed the GFA diet supplemented with VitD (GFA VitD+) significantly decreased the acute allergic skin response of whey sensitized mice when compared to the CMA mice fed VitD (VitD+) group (p < 0.05). The effect of GFA was not improved by extra VitD supplementation even though the CMA mice fed the GFA VitD+ diet had a significantly increased percentage of CD103+ DCs compared to the VitD+ group (p < 0.05). The VitD-deprived mice showed a high percentage of severe shock and many reached the humane endpoint; therefore, these groups were not further analyzed.

CONCLUSIONS

High-dose VitD supplementation in mice does not protect against CMA development in the presence or absence of GFA.

Polarization of protease-activated receptor 2 (PAR-2) signaling is altered during airway epithelial remodeling and deciliation

Protease-activated receptor 2 (PAR-2) is activated by secreted proteases from immune cells or fungi. PAR-2 is normally expressed basolaterally in differentiated nasal ciliated cells. We hypothesized that epithelial remodeling during diseases characterized by cilial loss and squamous metaplasia may alter PAR-2 polarization. Here, using a fluorescent arrestin assay, we confirmed that the common fungal airway pathogen Aspergillus fumigatus activates heterologously-expressed PAR-2. Endogenous PAR-2 activation in submerged airway RPMI 2650 or NCI-H520 squamous cells increased intracellular calcium levels and granulocyte macrophage-colony-stimulating factor, tumor necrosis factor α, and interleukin (IL)-6 secretion. RPMI 2650 cells cultured at an air-liquid interface (ALI) responded to apically or basolaterally applied PAR-2 agonists. However, well-differentiated primary nasal epithelial ALIs responded only to basolateral PAR-2 stimulation, indicated by calcium elevation, increased cilia beat frequency, and increased fluid and cytokine secretion. We exposed primary cells to disease-related modifiers that alter epithelial morphology, including IL-13, cigarette smoke condensate, and retinoic acid deficiency, at concentrations and times that altered epithelial morphology without causing breakdown of the epithelial barrier to model early disease states. These altered primary cultures responded to both apical and basolateral PAR-2 stimulation. Imaging nasal polyps and control middle turbinate explants, we found that nasal polyps, but not turbinates, exhibit apical calcium responses to PAR-2 stimulation. However, isolated ciliated cells from both polyps and turbinates maintained basolateral PAR-2 polarization, suggesting that the calcium responses originated from nonciliated cells. Altered PAR-2 polarization in disease-remodeled epithelia may enhance apical responses and increase sensitivity to inhaled proteases.

Molecular approaches to allergen-specific immunotherapy: Are we so far from clinical implementation?

Conventional allergen-specific immunotherapy (AIT), based on administrations of allergen extracts, represents up to now the unique protocol for the desensitization of allergic patients. Whereas the effectiveness of AIT was evidenced for the treatment of allergic rhinitis and allergic asthma, such strategy remains experimental for food allergies up to now. However, important issues are commonly associated with AIT as the quality of natural allergen extracts, the long duration and adverse side-effects which negatively affect successful desensitization together with the patient compliance. The rapid progression of molecular allergology made possible the quest of safer, shorter and more effective immunotherapeutic approaches. The aim of this review was to provide an update on these different innovative recombinant derivatives including their efficacy but also their limitations. Despite promising preclinical and early clinical studies, the absence of convincing data in large phase III trials precludes so far the translation of these immunotherapeutic candidates into the clinic.

Vitamin D, Autoimmune Disease and Rheumatoid Arthritis

Vitamin D has been reported to influence physiological systems that extend far beyond its established functions in calcium and bone homeostasis. Prominent amongst these are the potent immunomodulatory effects of the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The nuclear vitamin D receptor (VDR) for 1,25-(OH)2D3 is expressed by many cells within the immune system and resulting effects include modulation of T cell phenotype to suppress pro-inflammatory Th1 and Th17 CD4+ T cells and promote tolerogenic regulatory T cells. In addition, antigen-presenting cells have been shown to express the enzyme 1α-hydroxylase that converts precursor 25-hydroxyvitamin D3 (25-OHD3) to 1,25-(OH)2D3, so that immune microenvironments are able to both activate and respond to vitamin D. As a consequence of this local, intracrine, system, immune responses may vary according to the availability of 25-OHD3, and vitamin D deficiency has been linked to various autoimmune disorders including rheumatoid arthritis (RA). The aim of this review is to explore the immune activities of vitamin D that impact autoimmune disease, with specific reference to RA. As well as outlining the mechanisms linking vitamin D with autoimmune disease, the review will also describe the different studies that have linked vitamin D status to RA, and the current supplementation studies that have explored the potential benefits of vitamin D for prevention or treatment of RA. The overall aim of the review is to provide a fresh perspective on the potential role of vitamin D in RA pathogenesis and treatment.

Safety and value of skin test to sex hormones and sex hormone sensitivity desensitization in women with premenstrual syndrome

Background

Hypersensitivity to one's own sex hormones is not a new concept but it is an underappreciated one. Such a phenomenon may explain a large proportion of symptoms related to the menstrual cycle (such as premenstrual syndrome, PMS), cyclic pain syndromes or unexplained infertility. In this study we propose a novel diagnostic tool of hormonal skin testing which reveals sex hormones sensitivity with high clinical correlation, and a subsequent successful desensitization technique.

Methods

A group of 35 women with confirmed diagnosis of PMS were enrolled in the study in which they underwent a hormonal skin diagnostic skin testing procedure by intradermal injections of Progesterone (P), Estradiol (E2), Estrone (E1) and Estriol (E3). Skin reaction was monitored, and according to the reaction the patients were treated by serial desensitization by similar serial injections or placebo solvent. Response to treatment was monitored by assessing the change in the severity of PMS related symptoms.

Results

We show a positive correlation between PMS severity and skin sensitivity to sex hormones. Subsequent desensitization procedure led to a significant improvement in the severity of PMS related symptoms.

Conclusions

The testing and desensitization procedure is safe, sensitive and bares a high therapeutic potential in approach to resistant hormonal cycle related syndromes.

ClinicalTrials.gov Identifier

NCT00873262: Evaluation of Safety/Efficacy of Diagnostic Skin Test Panel and Desensitization Hormone Kit for Treatment of Premenstrual Syndrome (PMS) 2009.

Does a carrot a day keep the allergy away?

Vitamin A is an important micronutrient, from plants diet taken up as carotenoids, from animal food sources as retinol. Its active metabolite retinoic acid (RA) binds to nuclear hormone receptors, thereby regulating gene transcription programs in various cells. Adequate nutritional intake of vitamin A is essential for pre- and postnatal development, eyesight and reproduction, and it contributes to the maintenance and regulation of the immune system. Recent molecular studies indicate that lipocalins play an important role in the bioavailability of RA and its immune modulation against Th2 responses. There is emerging evidence that supply with vitamin A determines the susceptibility to allergic diseases: significantly reduced serum vitamin A levels are commonly observed in allergic patients compared to healthy controls. In line, findings from nutritional and clinical trials suggest that sufficient vitamin A supplementation in pregnancy prevents the development of allergic diseases in the offspring, and helps in controlling symptoms in adult asthmatics. Overall, retinoids have a key role in regulating immune homeostasis on mucosal surfaces because they are able to interfere with inflammatory signalling pathways. In this mini-review we will concentrate on the current knowledge about the influence of dietary and supplementary vitamin A on allergic diseases in humans from infancy to adulthood.