1alpha,25-dihydroxyvitamin D3 potentiates the beneficial effects of allergen immunotherapy in a mouse model of allergic asthma: role for IL-10 and TGF-beta

Vitamin D constrains inflammation by modulating the expression of key genes on Chr17q12-21.1

Vitamin D possesses immunomodulatory functions and vitamin D deficiency has been associated with the rise in chronic inflammatory diseases, including asthma (Litonjua and Weiss, 2007). Vitamin D supplementation studies do not provide insight into the molecular genetic mechanisms of vitamin D-mediated immunoregulation. Here, we provide evidence for vitamin D regulation of two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, reliably associated with autoimmune and chronic inflammatory diseases. We demonstrate increased vitamin D receptor (Vdr) expression in mouse lung CD4+ Th2 cells, differential expression of Chr17q12-21.1 and Chr17q21.2 genes in Th2 cells based on vitamin D status and identify the IL-2/Stat5 pathway as a target of vitamin D signaling. Vitamin D deficiency caused severe lung inflammation after allergen challenge in mice that was prevented by long-term prenatal vitamin D supplementation. Mechanistically, vitamin D induced the expression of the Ikzf3-encoded protein Aiolos to suppress IL-2 signaling and ameliorate cytokine production in Th2 cells. These translational findings demonstrate mechanisms for the immune protective effect of vitamin D in allergic lung inflammation with a strong molecular genetic link to the regulation of both Chr17q12-21.1 and Chr17q21.2 genes and suggest further functional studies and interventional strategies for long-term prevention of asthma and other autoimmune disorders.

The Association between Vitamin D, Interleukin-4, and Interleukin-10 Levels and CD23+ Expression with Bronchial Asthma in Stunted Children

Children with stunted growth have an increased risk of wheezing, and studies have shown that low levels of vitamin D and interleukin (IL)-10, along with increased IL-4 levels and CD23+ expression, are present in stunted and asthmatic children. To date, it is not known whether these factors are related to the incidence of asthma in stunted children. This case-control study investigated the association between vitamin D, IL-4, and IL-10 levels and CD23+ expression with bronchial asthma in stunted children. The study included 99 children aged 24-59 months, i.e., 37 stunted-sthmatic children (cases), 38 stunted children without asthma, and 24 non-stunted children with asthma. All children were tested for their 25(OH)D levels using chemiluminescent immunoassay (CLIA), IL-4 and IL-10 levels were measured through enzyme-linked immunosorbent assay (ELISA) testing, and CD23+ expression was measured through flow cytometry bead testing. The data were analyzed using chi-squared, Kruskal-Wallis, and Mann-Whitney tests. The results showed that stunted asthmatic children had a higher incidence of atopic family members than those without asthma. Additionally, stunted asthmatic children had a higher prevalence of vitamin D deficiency (48.6%) than the control group (44.7% and 20.8%). Furthermore, stunted asthmatic children had significantly lower levels of 25(OH)D [20.55 (16.18-25.55), p = 0.042] and higher levels of IL-4 [1.41 (0.95-2.40), p = 0.038], although there were no significant differences in IL-10 levels and CD23+ expression. The study concluded that low vitamin D and high IL-4 levels are associated with bronchial asthma in stunted children, while IL-10 and CD23+ do not show a significant association.

Vitamin D Role in Childhood Mite Allergy and Allergen Immunotherapy (AIT)

The post hoc analysis presented here aimed to address the influence of endogenous vitamin D in the immunological mechanism underlying effective mite allergoid immunotherapy (AIT). Previously, we have shown that in allergic children, after 12 months of this immunoactive treatment, functionally potentiated memory regulatory T cells are identified. Indeed, AIT is the only known treatment that is able to reshape the detrimental immune response against the allergen into a non-noxious one. Besides, VD is widely considered an immunoregulatory molecule that is endogenously produced and exogenously provided by foods and supplements that might interact with the AIT mechanism, thus affecting its outcome. Therefore, a post hoc analysis of the clinical and immunological data from three different cohorts of allergic patients was performed. One cohort (N = 70) was on a standard symptom-controlling pharmacological treatment, while the other two (N = 60 and N = 35) were treated with AIT for 12 months. In the first cohort, a lower mean endogenous VD level (<22 ng/mL) was observed along with worse symptoms and a greater use of medications. Remarkably, the comparison between two sub-cohorts of patients with a serum VD level above (N = 32) or below (N = 28) a cut-off value set at the mean value (27 ng/mL) revealed that optimal improvement of all clinical and immune parameters was achieved (as expected from effective AIT), irrespective of the VD level. Notably, the third analysis, carried out on one cohort of AIT patients that were also concomitantly taking VD3 as a food supplement (N = 19), was distinguished by an uppermost overall treatment outcome (the amelioration of symptoms, the lowest medication requirements, and a reduction in the total and allergen-specific IgE levels), as well as an increase in the allergen-specific tolerogenic memory T regulatory cells. These findings suggest that the endogenous VD level affects the allergy severity and allergen immunotherapy effectiveness. In addition, VD3 might be investigated as an add-on supplement to obtain the best out of immunotherapy in VD-deficient/-insufficient allergic patients. The immunogenic, but low-allergenic, mite allergoid used as the bioactive agent might have contributed to minimizing the allergic response and highlighting the immunological effects described here.

Antioxidant Intake and Biomarkers of Asthma in Relation to Smoking Status-A Review

Asthma is considered a chronic inflammatory disorder associated with airway hyperresponsiveness (AHR). Increased oxidative stress (OS) is a clinical feature of asthma, which promotes the inflammatory responses in bronchial/airway epithelial cells. Smokers and nonsmokers with asthma have been shown to have increases in several OS and inflammatory biomarkers. However, studies suggest significant differences in OS and inflammation biomarkers between smokers and nonsmokers. A few studies suggest associations between antioxidant intake from diet/supplements and asthma in patients with different smoking status. Evidence is lacking on the protective role of antioxidant vitamin and/or mineral consumption against asthma by smoking status with respect to inflammation and OS biomarkers. Therefore, the aim of this review is to highlight current knowledge regarding the relations between antioxidant intake, asthma, and its associated biomarkers, according to smoking status. This paper can be used to guide future research directions towards the health consequences of antioxidant intake in smoking and nonsmoking asthmatics.

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.

The inhibitory mechanisms of losartan and vitamin D on amiodarone-induced lung inflammation in rats: Role of mitogen-activated protein kinases/activator protein-1

Amiodarone (AMD), an antiarrhythmic drug, is used cautiously due to its lung toxicity that is characterized by alveolar inflammation followed by fatal fibrosis. AMD induces lung inflammation via increasing the alveolar macrophages and disturbing the balance of T-helper-1 (Th1) and Th2 cells cytokines. In this study, the role of the mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway in AMD-induced lung inflammation was evaluated. Also, the anti-inflammatory and antifibrotic effects of losartan and/or vitamin D were investigated following 7, 14, and 28 days of AMD administration. AMD resulted in lung injury, inflammatory infiltration, and increased pulmonary levels of inflammatory cytokines starting from Week 1 of exposure. A significant increase in serum levels of interleukin-4 along with a significant reduction of interferon-gamma, in addition to strong expression of CD68, were reported after 14 and 28 days of AMD administration reflecting Th1/Th2 cytokines imbalance and the accumulation of alveolar macrophages, respectively. The phosphorylation of MAPKs (ERK1/2, JNK, p38) and AP-1 was significantly enhanced starting from Week 1 of exposure. Marked expression of transforming growth factor beta-1 and massive deposition of collagen were detected after 28 days reflecting late fibrosis. All these abnormalities were significantly mitigated by vitamin D and its combination with losartan. Losartan alone has less prominent anti-inflammatory effects particularly after 28 days; however, it efficiently prevented late fibrosis. This study concludes that MAPKs/AP-1 pathway is involved in AMD-induced lung inflammation and that vitamin D and/or losartan could be used as a prophylactic agent to prevent AMD-induced lung toxicity.

Methods for Experimental Allergen Immunotherapy: Subcutaneous and Sublingual Desensitization in Mouse Models of Allergic Asthma

Allergic asthma is characterized by airway hyperresponsiveness, remodeling, and reversible airway obstruction. This is associated with an eosinophilic inflammation of the airways, caused by inhaled allergens such as house dust mite or grass pollen. The inhaled allergens trigger a type-2 inflammatory response with the involvement of innate lymphoid cells (ILC2) and Th2 cells, resulting in high immunoglobulin E (IgE) antibody production by B cells and mucus production by airway epithelial cells. As a consequence of the IgE production, subsequent allergen reexposure results in a classic allergic response with distinct early and late phases, both resulting in bronchoconstriction and shortness of breath. Allergen-specific immunotherapy (AIT) is the only treatment that is capable of modifying the immunological process underlying allergic responses including allergic asthma. Both subcutaneous AIT (SCIT) as well as sublingual AIT (SLIT) have shown clinical efficacy in long-term suppression of the allergic response. Although AIT treatments are very successful for rhinitis, application in asthma is hampered by variable efficacy, long duration of treatment, and risk of severe side effects. A more profound understanding of the mechanisms by which AIT induces tolerance to allergens in sensitized individuals is needed to be able to improve its efficacy. Mouse models have been very valuable in preclinical research for characterizing the mechanisms of desensitization in AIT and evaluating novel approaches to improve its efficacy. Here, we present a rapid and reproducible mouse model for allergen-specific immunotherapy. In this model, mice are sensitized with two injections of allergen adsorbed to aluminum hydroxide, followed by subcutaneous injections (SCIT) or sublingual administrations (SLIT) of allergen extracts as an immunotherapy treatment. Finally, mice are challenged by intranasal allergen administrations. We will also describe the protocols as well as the most important readout parameters for the measurements of invasive lung function, serum immunoglobulin levels, isolation of bronchoalveolar lavage fluid (BALF), and preparation of cytospin slides. Moreover, we describe how to perform ex vivo restimulation of lung single-cell suspensions with allergens, flow cytometry for identification of relevant immune cell populations, and ELISAs and Luminex assays for assessment of the cytokine concentrations in BALF and lung tissue.

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.

Vitamin D high doses supplementation could represent a promising alternative to prevent or treat COVID-19 infection

Although we lack enough evidence to justify supplementing with vitamin D in the prevention and treatment of COVID-19 infection, it is increasingly feasible that this hypothesis is valid. Two general underlying mechanisms should be considered. One would be the anti-infectious and immunomodulatory action that it exerts by improving intercellular barriers by stimulating innate immunity, as well as by modulating adaptive immunity. Also, vitamin D reduces the production of inflammatory cytokines, such as IL-2 and interferon-gamma (INFγ). More recently, multiple pleiotropic effects have been demonstrated on the actions of vitamin D at the anti-inflammatory and immunomodulatory level with positive results in studies with influenza, coronavirus, and other respiratory infections. An inverse relationship between serum vitamin D levels and the prevalence of the respiratory infectious disease has been described. Of interest, another mechanistic approach responds to considering the inhibition of the renin-angiotensin-aldosterone system (RAAS), which is exacerbated in COVID-19 infection because the virus binds to the enzyme ACE2, making more angiotensin II available to cause damage. Vitamin D inhibits mediators of RAAS – present in all cells of the body – and by inhibiting ACE activity and increasing ACE2, it lowers angiotensin II levels. We present studies with proposals for recommended doses of vitamin D, and although a single guideline is not specified, the possible benefits are promising. Finally, the purpose of this review is to share this idea with health professionals to ignite the debate and call for critical reflection, so that it can contribute to the undertaking of more and better clinical designs to validate the benefits of using high doses of vitamin D for the benefit of public health and especially in times of crisis for COVID-19.

Vitamin D high doses supplementation could represent a promising alternative to prevent or treat COVID-19 infection

Although we lack enough evidence to justify supplementing with vitaminD in the prevention and treatment of COVID-19 infection, it is increasingly feasible that this hypothesis is valid. Two general underlying mechanisms should be considered. One would be the anti-infectious and immunomodulatory action that it exerts by improving intercellular barriers by stimulating innate immunity, as well as by modulating adaptive immunity. Also, vitaminD reduces the production of inflammatory cytokines, such as IL-2 and interferon-gamma (INF-γ). More recently, multiple pleiotropic effects have been demonstrated on the actions of vitaminD at the anti-inflammatory and immunomodulatory level with positive results in studies with influenza, coronavirus, and other respiratory infections. An inverse relationship between serum vitaminD levels and the prevalence of the respiratory infectious disease has been described. Of interest, another mechanistic approach responds to considering the inhibition of the renin-angiotensin-aldosterone system (RAAS), which is exacerbated in COVID-19 infection because the virus binds to the enzyme ACE2, making more angiotensinII available to cause damage. VitaminD inhibits mediators of RAAS - present in all cells of the body - and by inhibiting ACE activity and increasing ACE2, it lowers angiotensinII levels. We present studies with proposals for recommended doses of vitaminD, and although a single guideline is not specified, the possible benefits are promising. Finally, the purpose of this review is to share this idea with health professionals to ignite the debate and call for critical reflection, so that it can contribute to the undertaking of more and better clinical designs to validate the benefits of using high doses of vitaminD for the benefit of public health and especially in times of crisis for COVID-19.

Vitamin D supplementation as a rational pharmacological approach in the COVID-19 pandemic

The COVID-19 pandemic has reached most of the countries worldwide causing death, which often results from an inflammatory storm associated with severe acute respiratory syndrome (SARS). This has prompted researchers to seek specific novel and definitive treatments urgently. In this context, it is interesting to evaluate the preventive and therapeutic effects of existing pharmacological agents that could be useful. In this regard, vitamin D supplementation, particularly in individuals likely to be deficient, may be a promising option. Vitamin D is a hormone that modulates many of the same inflammatory and oxidative signaling pathways triggered during COVID-19. For example, vitamin D suppresses the actions of the renin-angiotensin system, which has a determining role in the pathophysiology of the inflammatory response related to COVID-19. This paper analyzes the evidence that vitamin D supplementation might be a valuable preventive/therapeutic measure in groups at risk for or infected with COVID-19. It also discusses how clinical studies could be best designed to evaluate the possible advantages of vitamin D supplementation for the benefit of public health during the pandemic.

New and old adjuvants in allergen-specific immunotherapy: With a focus on nanoparticles

Allergic diseases have remarkably increased in recent years. Nowadays, efforts for curing and management of these disorders are an important concern worldwide. Allergen-specific immunotherapy (ASIT) has recently gained more attention as a means for the management of allergic diseases. Adjuvants or helper agents are materials applied for better stimulating and shifting of protective responses, and these belong to an extremely diverse collection of complexes. The main function of adjuvants includes acting as depot foundations, transferring vehicles, and immunostimulators. Immunostimulatory adjuvants have gained increasing attention for ASIT. In this regard, the present study provides a review of old and new adjuvants used in allergen immunotherapy.

COMMD8 changes expression during initial phase of wasp venom immunotherapy

BACKGROUND

Hymenoptera venom allergy (HVA) is of great concern because of the possibility of anaphylaxis, which may be fatal. Venom immunotherapy (VIT) is the only disease-modifying treatment in HVA and, although efficient, its mechanism remains partially unknown. Gene expression analysis may be helpful for establishing a proper model of tolerance induction during the build-up phase of VIT. The present study aimed to analyze how the start of VIT changes the expression of 15 selected genes.

METHODS

Forty-five patients starting VIT with a wasp venom allergy were enrolled. The diagnosis was established based on anaphylaxis history (third or fourth grade on the Mueller scale) and positive soluble immunoglobulin E and/or skin tests. Two blood collections were performed in the patient group: before and after 3 months of VIT. One sample was taken in the control group. Gene expression analysis was performed using a reverse transcriptase-polymerase chain reaction with microfluidic cards and normalized to the 18S housekeeping gene.

RESULTS

Commd8 was the only gene that changed expression significantly after the start of VIT (p = 0.012). Its expression decreased towards the levels observed in the healthy controls. Twelve out of 15 genes (commd8, cldn1, cngb3, fads1, hes6, hla-drb5, htr3b, prlr, slc16a4, snx33, socs3 and twist2) revealed a significantly different expression compared to the healthy controls.

CONCLUSIONS

The present study shows that commd8 changes significantly its expression during initial phase of VIT. This gene might be a candidate for VIT biomarker in future studies.

1,25(OH)2VitD3 supplementation enhances suppression of grass pollen-induced allergic asthma by subcutaneous and sublingual immunotherapy in a mouse model

Allergen specific immunotherapy (AIT) can provide long-term alleviation of symptoms for allergic disease but is hampered by suboptimal efficiency. We and others have previously shown that 1,25(OH)2-VitaminD3 (VitD3) can improve therapeutic efficacy of AIT. However, it is unknown whether VitD3 supplementation has similar effects in sublingual and subcutaneous immunotherapy. Therefore, we aimed to test VitD3 supplementation in both grass pollen (GP) subcutaneous-IT (SCIT) and sublingual-IT (SLIT) in a mouse model for allergic airway inflammation. To this end, GP-sensitized BALB/c mice received GP-SCIT or GP-SLIT with or without 10 ng VitD3, followed by intranasal GP challenges and measurement of airway hyperresponsiveness (AHR) and inflammation. VitD3 supplementation of GP-SCIT resulted in enhanced induction of GP-specific (sp)-IgG2a and suppression of spIgE after challenge. In addition, eosinophil numbers were reduced and levels of IL10 and Amphiregulin were increased in lung tissue. In GP-SLIT, VitD3 supplementation resulted in enhanced sp-IgG2a levels in serum, enhanced suppression of eosinophils and increased IL10 levels in lung tissue, as well as suppression of AHR to methacholine. These data show that VitD3 increases efficacy of both SCIT and SLIT, by enhancing induction of blocking antibodies and suppression of airway inflammation, underscoring the relevance of proficient VitD3 levels for successful AIT.

Lungs as target of COVID-19 infection: Protective common molecular mechanisms of vitamin D and melatonin as a new potential synergistic treatment

COVID-19 pandemic has a high mortality rate and is affecting practically the entire world population. The leading cause of death is severe acute respiratory syndrome as a consequence of exacerbated inflammatory response accompanied by uncontrolled oxidative stress as well as the inflammatory reaction at the lung level. Until now, there is not a specific and definitive treatment for this pathology that worries the world population, especially the older adults who constitute the main risk group. In this context, it results in a particular interest in the evaluation of the efficacy of existing pharmacological agents that may be used for overcoming or attenuating the severity of this pulmonary complication that has ended the lives of many people worldwide. Vitamin D and melatonin could be good options for achieving this aim, taking into account that they have many shared underlying mechanisms that are able to modulate and control the immune adequately and oxidative response against COVID-19 infection, possibly even through a synergistic interaction. The renin-angiotensin system exaltation with consequent inflammatory response has a leading role in the physiopathology of COVID-19 infection; and it may be down-regulated by vitamin D and melatonin in many organs. Therefore, it is also essential to analyze this potential therapeutic association and their relation with RAS as part of this new approach.

Optimal dietary curcumin improved growth performance, and modulated innate immunity, antioxidant capacity and related genes expression of NF-κB and Nrf2 signaling pathways in grass carp (Ctenopharyngodon idella) after infection with Aeromonas hydrophila

This study investigated the effects of dietary curcumin on growth performance, non-specific immunity, antioxidant capacity and related genes expression of NF-κB and Nrf2 signaling pathways in grass carp (Ctenopharyngodon idella). A total of 525 juvenile grass carps with mean initial body weight of (5.30 ± 0.10) g were randomly distributed into five groups with three replicates each, fed five diets containing graded levels of curcumin (0, 196.11, 393.67, 591.46 and 788.52 mg/kg diet) for 60 days. After feeding trial, fifteen fish per tank were challenged with Aeromonas hydrophila and the mortalities were recorded for 7 days. The results showed that optimal dietary curcumin (393.67 mg/kg diet) improved the weight gain (WG) and specific growth rate (SGR) of juvenile grass carp, reduced feed conversion ratio (FCR) and the mortalities after challenge (P < 0.05). Moreover, optimal dietary curcumin increased the activities of lysozyme (LYZ) and acid phosphatase (ACP), and complement 3 (C3) and C4 levels, decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum of grass carp after injection with A. hydrophila (P < 0.05). Meanwhile, optimal dietary curcumin up-regulated the mRNA levels of LYZ, C3 and antimicrobial peptides [hepcidin, liver-expressed antimicrobial peptide-2 (LEAP-2), β-defensin], and anti-inflammatory cytokines of interleukin-10 (IL-10) and transforming growth factor β1 (TGF-β1), and inhibitor of κBα (IκBα), whereas down-regulated pro-inflammatory cytokines of tumor necrosis factor-α (TNF-α), IL-1β, IL-6 and IL-8, and nuclear factor kappa B p65 (NF-κB p65), IκB kinases (IKKα, IKKβ and IKKγ) mRNA levels in the liver and blood of grass carp after injection with A. hydrophila (P < 0.05). In addition, optimal dietary curcumin increased the reduced glutathione (GSH) content and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR), reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels in the liver of grass carp after injection with A. hydrophila (P < 0.05). Meanwhile, optimal dietary curcumin up-regulated the mRNA levels of these antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2), whereas down-regulated Kelch-like ECH-associated protein (Keap) 1a and Keap 1b mRNA levels (P < 0.05) in the liver and blood of grass carp after injection with A. hydrophila. Thus, optimal dietary curcumin supplementation could promote growth of juvenile grass carp, reduce FCR, and enhance disease resistance, innate immunity and antioxidant capacity of fish, attenuating inflammatory response. However, dietary excessive curcumin had negative effect on fish. Based on second-order regression analysis between dietary curcumin contents and weight gain, the optimum requirement of dietary curcumin in juvenile grass carp was determined to be 438.20 mg/kg diet.

The role of vitamin D in increasing circulating T regulatory cell numbers and modulating T regulatory cell phenotypes in patients with inflammatory disease or in healthy volunteers: A systematic review

Background

The evidence for vitamin D and other agents that experimentally modulate T regulatory cells (Tregs) for the treatment of patients with autoimmune or allergic diseases has not been established.

Objective

We have undertaken a systematic review of randomised controlled trials to assess the efficacy of vitamin D, vitamin A, niacin and short-chain fatty acids in enhancing absolute Treg numbers and phenotypes in patients with inflammatory or autoimmune disease.

Methods

This systematic review was conducted using a predefined protocol (PROSPERO International prospective register of systematic reviews, ID = CRD42016048648/ CRD42016048646). Randomised controlled trials of patients with inflammatory or autoimmune disease or healthy participants which compared either oral vitamin D or vitamin A or short-chain fatty acids with control or placebo and measured the absolute concentration of proportion of Tregs were eligible for inclusion. Searches of electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PUBMED and Web of Science) identified eight eligible independent trials (seven autoimmune disease trials, one trial of healthy subjects). Data were extracted by two reviewers and the risk of study bias was assessed using Cochrane Collaboration methodology.

Results

Planned meta-analysis was not possible due to the heterogeneous nature of the studies. Nevertheless, in five trials of autoimmune disorders which measured the proportion of Tregs, a higher proportion was observed in the vitamin D group compared to controls at 12 months in all but one trial. In the trial of healthy subjects, a significant difference was reported, with a higher percentage of Tregs observed in the vitamin D group (at 12 weeks, mean 6.4% (SD 0.8%) (vitamin D) vs 5.5% (1.0%) (placebo). There were no trials to assess the efficacy of vitamin A, niacin and short-chain fatty acids in enhancing absolute Treg numbers.

Conclusions

Vitamin D supplementation may increase Treg/CD3 ratios in both healthy individuals and patients with autoimmune disorders and may increase Treg function. There remains a need for further suitably powered clinical studies aimed at enhancing Treg numbers and/or function.

[Analyses of Foxp3+ Treg cells and Tr1 cells in subcutaneous immunotherapy-treated allergic individuals in humans and mice]

Subcutaneous immunotherapy (SCIT) is a causative treatment for allergic diseases. More recently, it has become clear that regulatory T (Treg) cells are increased by SCIT. Treg cells are generally divided into two main groups: 1) CD25⁺ Foxp3⁺ CD4⁺ T cells (Foxp3⁺ Treg cells) and 2) IL-10-producing Foxp3^- CD4⁺ T cells (Tr1 cells). We demonstrated that the number of Tr1 cells in peripheral blood mononuclear cells in SCIT-treated pollinosis patients were significantly higher than that in non-SCIT-treated patients, but Foxp3⁺ Treg cells were not. Consistent with the results of human peripheral blood, Tr1 cells were increased in the lungs of asthmatic mice by SCIT, but Foxp3⁺ Treg cells were not. Moreover, in vitro-induced Tr1 cells were responded to the antigen to produce a large amount of IL-10 in in vitro and in vivo. Adoptive transfer of the induced Tr1 cells significantly suppressed the development of asthma. In any species of human and mouse, the increase in Tr1 cells rather than Foxp3⁺ Treg cells could be important for the effects of SCIT. The increased Tr1 cells by SCIT functionally suppressed allergic asthma probably via production of IL-10 in response to the specific antigen. Therefore, analyses of the induction mechanisms of Tr1 cells and search for compounds which induce Tr1 cells are thought to lead to development of more efficient SCIT.

Evaluation of the efficacy of isopathic immunotherapy in the treatment of allergic asthma in BALB/C mice

Introduction: Homeopathy is a therapeutic method based on the fundamental principle of "like cures like." Homeopathic remedies are extremely dilute but involve vigorous shaking at each dilution. Isopathy is one approach of homeopathy, in which the causative agents or products of a disease are used to treat the same disease. Allergen immunotherapy is the only potential disease-modifying treatment for allergic patients. Subcutaneous immunotherapy is more effective than sublingual immunotherapy. However, subcutaneous immunotherapy is ineffective at a low dose, whereas at high doses it can result in an unacceptably high frequency of systemic reactions. In the current study, we evaluated the efficacy of isopathic immunotherapy with highly diluted ovalbumin (HD OVA) in the treatment of OVA-induced allergic asthma in BALB/c mice.Methods: BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received HD OVA on days 21, 22, 32 and 41 (8 h after the last challenge) of the treatment. The mice were challenged with OVA (5%) aerosols on days 35, 38 and 41 for 20 minutes using an ultrasonic nebulizer and sacrificed the next day.Results: Isopathic immunotherapy significantly reduced lung tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and interleukin-4 production. It also insignificantly increased the production of transforming growth factor-beta and proliferation of regulatory T cells against the allergen.Conclusion: Isopathic immunotherapy may be a good candidate treatment for allergic asthma.

Nicotine, as a novel tolerogenic adjuvant, enhances the efficacy of immunotherapy in a mouse model of allergic asthma

An increasing trend in the incidence of allergic diseases including asthma and related morbidity and mortality is observed worldwide during the last decades. Allergen-specific immunotherapy is suggested for the treatment of some allergic diseases; nevertheless, there is always a menace of uncommon, but life-treating reactions due to increasing the administration of allergen extract doses. Hence, improving its efficacy may reduce the required doses as well as the risk of such reactions. The current study aimed at examining the effects of nicotine (NIC), as a tolerogenic adjuvant, on the improvement of immunotherapy efficacy in a mouse model of allergic asthma. BALB/c mice were sensitized using alum and ovalbumin (OVA) on the days 0 and 7. Mice received OVA either alone or together with NIC (1 or 10 mg/kg) on the days 21, 23, and 25. Then, the mice were challenged with OVA 5% using a nebulizer on the days 35, 38, and 41 and sacrificed the next day. Co-administration of OVA and NIC decreased the inflammation of the lung tissue, eosinophils count in the bronchoalveolar lavage (BAL) fluid, the serum level of OVA-specific immunoglobulin E, as well as interleukin (IL)-4 production, while increasing the population of antigen-specific regulatory T-cells (Treg cells) and transforming growth factor-β/IL-4 (TGF-β/IL-4) ratio compared to the OVA and control groups in a dose-dependent manner. Collectively, the findings suggest that administration of NIC plus the allergen increased immunotherapy efficacy through decreasing allergic inflammation and allergic responses intensity, and increasing Treg cells population.

Allergen-specific immunotherapy induces regulatory T cells in an atopic dermatitis mouse model

BACKGROUND

Several studies have demonstrated that allergen-specific immunotherapy (SIT) can be an effective treatment for atopic dermatitis (AD). However, there is no relevant mouse model to investigate the mechanism and validate the novel modality of SIT in AD.

METHODS

NC/Nga mice with induced AD-like skin lesions received a subcutaneous injection of SIT (an extract of the house dust mite Dermatophagoides farinae [DfE]) or placebo for 5 weeks). Clinical and histological improvements of AD-like skin lesions were examined. The responses of local and systemic regulatory T (Treg) cells, natural killer (NK) cells, B cells, serum immunoglobulin, and T-cell cytokine response to DfE were evaluated to determine the underlying mechanism of the observed results.

RESULTS

Specific immunotherapy significantly improved AD-like skin lesions. Histologically, SIT decreased epidermal thickness and reduced inflammatory cell infiltration, especially that of eosinophils. Concomitantly, SIT suppressed Th2 responses and induced local infiltration of Treg cells into the skin. Also, SIT induced the immunoglobulin G4 and attenuated allergen-specific immunoglobulin E. Furthermore, SIT induced local and systemic IL-10-producing Treg cells and regulatory NK cells.

CONCLUSION

We established a SIT model on AD mice and showed that our model correlates well with previous reports about SIT-treated patients. Also, we revealed NK cells as another possible resource of IL-10 in SIT. Based on our results, we suggest our SIT model as a useful tool to investigate mechanism of action of SIT and to validate the efficacy of new SIT modalities for the treatment of AD.

Evaluation of the efficacy of nicotine in treatment of allergic asthma in BALB/c mice

Nicotine, an nAChR agonist, shows prominent anti-inflammatory properties, and some studies have illustrated its suppressive effects on inflammation. Here, we have examined whether nicotine as a medicine may have beneficial effects on the treatment of asthma in a mouse model of allergic asthma. BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received nicotine with concentrations of 1 and 10 mg/kg three times every other day. After 10 days, the mice were challenged with OVA (5%) using an ultrasonic nebulizer and died the next day. Our results showed that the administration of nicotine reduced lung-tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and IL-4 production, while it increased the TGF-β/IL-4 ratio and the number of Treg cells. Our results showed that nicotine applies its suppressive effects in a dose-dependent manner: administration of 10 mg/kg of nicotine showed more suppressive effects than 1 mg/kg. Such data suggested that nicotine might be a good candidate to be used as a medicine in the treatment of allergic asthma by decreasing allergic inflammation severity and potentiating Treg cells proliferation against the allergen.

Phenotype analyses of IL-10-producing Foxp3- CD4+ T cells increased by subcutaneous immunotherapy in allergic airway inflammation

INTRODUCTION

The mechanisms of allergen immunotherapy are not fully elucidated. Here, we sought to develop a murine model to demonstrate the effectiveness of subcutaneous immunotherapy (SCIT) for allergic responses. As excessive antigen dosages may induce immune tolerance in sensitized mice, the effects of SCIT were assessed by varying the antigen dosage. The mechanisms of SCIT were analyzed by focusing on the induction of Foxp3⁺ Treg cells and IL-10-producing Foxp3^- CD4⁺ T cells, as well as on the phenotype of the latter cells.

METHODS

Ovalbumin (OVA) + Al(OH)₃-sensitized mice received subcutaneous dosages of OVA at 0.01, 0.1 or 1 mg/animal for SCIT, followed by intratracheal challenges with OVA at 5, 50 or 500 μg/animal.

RESULTS

The maximum effects of SCIT were observed with 1 mg/animal of OVA for airway inflammation induced by 5 μg/animal of OVA, in which airway eosinophilia and Th2 cytokine production were markedly suppressed. The increase in the OVA-specific IgE level was significantly suppressed by SCIT. The development of bronchial epithelial thickening and mucus accumulation were also suppressed by SCIT. Concomitantly, IL-10-producing Foxp3^- CD4⁺ T cells were increased in the lungs by SCIT, but Foxp3⁺ Treg cells were not. Most of the induced IL-10-producing Foxp3^- CD4⁺ T cells were negative for either IL-5 or LAG-3, but positive for CD49b.

CONCLUSION

We successfully developed an airway allergic model for SCIT. It was suggested that most of IL-10-producing Foxp3^- CD4⁺ regulatory T cells increased by SCIT in the lungs were CD49b⁺ CD4⁺ regulatory T cells, but neither Th2 cells nor Tr1 cells.

Budesonide and Calcitriol Synergistically Inhibit Airway Remodeling in Asthmatic Mice

Background and Objective

While calcitriol can inhibit airway remodeling in asthmatic mice, the mechanism remains unclear. The purpose of this study was to explore the mechanism of action of calcitriol on airway remodeling in asthma and its interaction with budesonide.

Methods

A mouse model of asthma was established by allergic sensitization and challenge with ovalbumin. The mice were treated with budesonide, calcitriol, or budesonide plus calcitriol. The expression of airway remodeling-related proteins, transforming growth factor β (TGFβ) signaling pathway-related proteins, the glucocorticoid receptor, and vitamin D receptor (VDR) was determined by immunohistochemical staining and Western blot analysis. Quantitative real-time PCR was used to determine the expression of microRNA-21 (miR-21) in the lung tissue of mice.

Results

Monotherapy with budesonide or calcitriol inhibited the high expression of collagen type I protein and upregulated the low expression of Smad7 in asthmatic mice. There was a synergistic interaction between budesonide and calcitriol in combined treatment. The expression of miR-21 in the combined treatment group was significantly lower than that in the calcitriol treatment group. VDR expression in the combined treatment group was significantly higher than that of the calcitriol treatment group.

Conclusion

Budesonide and calcitriol have a synergistic effect on airway remodeling in asthmatic mice.

Differential effects of phototherapy, adalimumab and betamethasone-calcipotriol on effector and regulatory T cells in psoriasis

BACKGROUND

Psoriasis is a chronic T-cell-mediated skin disease with marked social and economic burdens. Current treatments are unsatisfactory, with unpredictable remission times and incompletely understood modes of action. Recent advances in our understanding of the pathogenesis of psoriasis have identified the imbalance between CD4⁺ T effector cells, particularly the T helper (Th)17 subset, and regulatory T cells (Tregs) as key to the development of psoriatic lesions, and therefore a novel therapeutic target.

OBJECTIVES

To quantify in patients the effects of three commonly used psoriasis treatment modalities on the Th1, Th2, Th17 and Treg subsets, and to test whether any change correlates with clinical response.

METHODS

Flow cytometry was used to enumerate Th1, Th2, Th17 and Treg subsets in blood and skin of patients with psoriasis before and after receiving any of the following treatments: narrowband ultraviolet B (NB-UVB), adalimumab and topical betamethasone-calcipotriol combination (Dovobet^® ) RESULTS: All patients responded clinically to the treatments. NB-UVB significantly increased the numbers of circulating and skin Tregs, while, by contrast, adalimumab reduced Th17 cells in these compartments, and Dovobet had dual effects by both increasing Tregs and reducing Th17 cells.

CONCLUSIONS

The differential effects reported here for the above-mentioned treatment modalities could be exploited to optimize or design therapeutic strategies to overcome the inflammatory drivers more effectively and restore the Th17-Treg balance in psoriasis.

Clinical and immunological effects of vitamin D supplementation during the pollen season in children with allergic rhinitis

INTRODUCTION

Vitamin D deficiency has been proposed as a potential contributing factor in patients with allergic diseases. We compared the clinical and immunological effects of vitamin D supplementation to placebo during the pollen season in children with allergic rhinitis.

MATERIAL AND METHODS

Thirty-eight children aged 5-12, sensitive to grass pollen, participated in a prospective, randomized, double-blind, placebo-controlled trial. Children received either vitamin D 1000 IU daily supplementation or placebo. We studied symptoms/medication score, lung function, exhaled nitric oxide concentration (FENO), methacholine bronchial provocation test and serum level of 25(OH)D, as well as; CD4+CD25+Foxp3+ cells, TLR4, IL-1, IL-6, TNF and the IL-10 and transforming growth factor β1 (TGF-β1) levels in cell culture supernatants.

RESULTS

Vitamin D therapy was effective in reduction of the symptoms/medication score (p = 0.0371). In vitamin D group an increase in the CD4+CD25+Foxp3+ cells (7.06 vs. 10.5%; p = 0.0013) and serum 25(OH)D concentration (49.6 vs. 96.6 ng/ml; p = 0.0001) and in control group an increase in FENO (15.6 vs. 21 ppb; p = 0.0331) and serum 25(OH)D level were observed (82.9 vs. 100.3 ng/ml; p = 0.0003).We revealed a higher increase from baseline in the percentage of CD4+CD25+Foxp3+ cells in the vitamin D group compared to the control group (p = 0.0058). A significant correlation between CD4+CD25+Foxp3+ cell induction and FENO reduction in the vitamin D group was observed (p = 0.0217).

CONCLUSIONS

Vitamin D 1000 IU as a supplementary treatment of grass pollen allergy in children with allergic rhinitis during the pollen season significantly reduced the symptoms/medication score. The study revealed an immunological effect of vitamin D.

Generation of regulatory dendritic cells after treatment with paeoniflorin

Regulatory dendritic cells are a potential therapeutic tool for assessing a variety of immune overreaction diseases. Paeoniflorin, a bioactive glucoside extracted from the Chinese herb white paeony root, has been shown to be effective at inhibiting the maturation and immunostimulatory function of murine bone marrow-derived dendritic cells. However, whether paeoniflorin can program conventional dendritic cells toward regulatory dendritic cells and the underlying mechanism remain unknown. Here, our study demonstrates that paeoniflorin can induce the production of regulatory dendritic cells from human peripheral blood monocyte-derived immature dendritic cells in the absence or presence of lipopolysaccharide (LPS) but not from mature dendritic cells, thereby demonstrating the potential of paeoniflorin as a specific immunosuppressive drug with fewer complications and side effects. These regulatory dendritic cells treated with paeoniflorin exhibited high CD11b/c and low CD80, CD86 and CD40 expression levels as well as enhanced abilities to capture antigen and promote the proliferation of CD4(+)CD25(+) T cells and reduced abilities to migrate and promote the proliferation of CD4(+) T cells, which is associated with the upregulation of endogenous transforming growth factor (TGF)-β-mediated indoleamine 2,3-dioxygenase (IDO) expression. Collectively, paeoniflorin could program immature dendritic cells (imDCs) and imDCs stimulated with LPS toward a regulatory DC fate by upregulating the endogenous TGF-β-mediated IDO expression level, thereby demonstrating its potential as a specific immunosuppressive drug.

Enhancing Allergen-Presentation Platforms for Sublingual Immunotherapy

Sublingual immunotherapy (SLIT) relies on high doses of allergens to treat patients with type I allergies. Although SLIT is commonly performed without any adjuvant or delivery system, allergen(s) could be further formulated with allergen-presentation platforms to better target oral dendritic cells eliciting regulatory immune responses. Improving the availability of allergens to the immune system should enhance SLIT efficacy, while allowing to decrease allergen dosing. Herein, we present an overview of adjuvants and vector systems that have been, or could be, considered as candidate allergen-presentation platforms for the sublingual route. Such platforms encompass adjuvants capable of stimulating allergen-specific T_H1 and/or regulatory CD4⁺ T-cell responses, including 1,25-dihydroxy vitamin D₃, glucocorticoids, Toll-like receptor ligands as well as selected bacterial probiotic strains. A limiting factor for SLIT efficacy is the number of dendritic cells capturing the allergens in the upper layers of oral tissues. Thus, adsorption or encapsulation of the allergen(s) within mucoadhesive particulate vector (or delivery) systems also has the potential to significantly enhance SLIT efficacy due to a facilitated allergen uptake by tolerogenic oral dendritic cells.

1&#945;,25-dihydroxyvitamin D3 Attenuates TGF-&#946;-Induced Pro-Fibrotic Effects in Human Lung Epithelial Cells through Inhibition of Epithelial-Mesenchymal Transition

Pulmonary fibrosis is a progressive fibrotic lung disease of persisting lung injury and ineffective wound repair, with poor prognosis. Epithelial-mesenchymal transition (EMT) of alveolar epithelia cells is an early event in the development of pulmonary fibrosis, and transforming growth factor β (TGF-β) is an acknowledged inducer of EMT. Epidemiological studies demonstrated that serum levels of 25-hydroxy-vitamin D were associated with the presence of fibrosis diseases. We investigated whether vitamin D attenuated TGF-β-induced pro-fibrotic effects through inhibiting EMT in human alveolar epithelia A549 cells. A549 cells were cultured with TGF-β alone or in combination with 1α,25-dihydroxyvitamin D3 (1α,25(OH)₂D₃). TGF-β increased the expression of the mesenchymal markers (N-cadherin and Vimentin), and decreased the expression of epithelial markers (E-cadherin). 1α,25(OH)₂D₃ attenuated these TGF-β-induced alterations. Furthermore, the EMT-related transcription factors (Snail and β-catenin) and the extracellular matrix genes (Collagen I and fibronectin) were inhibited by 1α,25(OH)₂D₃, while the expression of vitamin D receptor (VDR) was elevated. In addition, 1α,25(OH)₂D₃ alleviated the cell migration and the invasion abilities in TGF-β-stimulated A549 cells, determined by the scratch wound healing and transwell assays. Our findings suggested that 1α,25(OH)₂D₃ inhibited the pro-fibrotic phenotype of lung epithelial cells under TGF-β stimulation and provided new clues in the clinical management of pulmonary fibrosis.

Vitamin D and the lung

Vitamin D metabolism is complex and its deficiency has proven to be deleterious in bone health, and to have significant effects on the immune and cardiovascular systems. Vitamin D has also been associated with pulmonary diseases outcomes. This review will focus on vitamin D metabolism, and studies performed mostly in children with asthma or Cystic Fibrosis.

Effect of Prenatal versus Postnatal Vitamin D Deficiency on Pulmonary Structure and Function in Mice

Epidemiologic studies have linked gestational vitamin D deficiency to respiratory diseases, although mechanisms have not been defined. We hypothesized that antenatal vitamin D deficiency would impair airway development and alveolarization in a mouse model. We studied the effect of antenatal vitamin D deficiency by inducing it in pregnant mice and then compared lung development and function in their offspring to littermate controls. Postnatal vitamin D deficiency and sufficiency models from each group were also studied. We developed a novel tracheal ultrasound imaging technique to measure tracheal diameter in vivo. Histological analysis estimated tracheal cartilage total area and thickness. We found that vitamin D-deficient pups had reduced tracheal diameter with decreased tracheal cartilage minimal width. Vitamin D deficiency increased airway resistance and reduced lung compliance, and led to alveolar simplification. Postnatal vitamin D supplementation improved lung function and radial alveolar count, a parameter of alveolar development, but did not correct tracheal narrowing. We conclude that antenatal vitamin D deficiency impairs airway and alveolar development and limits lung function. Reduced tracheal diameter, cartilage irregularity, and alveolar simplification in vitamin D-deficient mice may contribute to increased airways resistance and diminished lung compliance. Vitamin D supplementation after birth improved lung function and, potentially, alveolar simplification, but did not improve defective tracheal structure. This mouse model offers insight into the mechanisms of vitamin D deficiency-associated lung disease and provides an in vivo model for investigating preclinical preventive and therapeutic strategies.

Subcutaneous and Sublingual Immunotherapy in a Mouse Model of Allergic Asthma

Allergic asthma, caused by inhaled allergens such as house dust mite or grass pollen, is characterized by reversible airway obstruction, associated with an eosinophilic inflammation of the airways, as well as airway hyper responsiveness and remodeling. The inhaled allergens trigger a type-2 inflammatory response with involvement of innate lymphoid cells (ILC2) and Th2 cells, resulting in high production of immunoglobulin E (IgE) antibodies. Consequently, renewed allergen exposure results in a classic allergic response with a distinct early and late phase, both resulting in bronchoconstriction and shortness of breath. Allergen specific immunotherapy (AIT) is the only treatment that is capable of modifying the immunological process underlying allergic responses including allergic asthma and both subcutaneous AIT (SCIT) as well as sublingual AIT (SLIT) have proven clinical efficacy in long term suppression of the allergic response. Although these treatments are very successful for rhinitis, application of AIT in asthma is hampered by variable efficacy, long duration of treatment, and the risk of severe side-effects. A more profound understanding of the mechanisms by which AIT achieves tolerance to allergens in sensitized individuals is needed to improve its efficacy. Mouse models have been very valuable as a preclinical model to characterize the mechanisms of desensitization in AIT and to evaluate novel approaches for improved efficacy. Here, we present a rapid and reproducible mouse model for allergen-specific immunotherapy. In this model, mice are sensitized with two injections of allergen absorbed to aluminum hydroxide to induce allergic sensitization, followed by subcutaneous injections (SCIT) or sublingual administrations (SLIT) of the allergen as immunotherapy treatment. Finally, mice are challenged by three intranasal allergen administrations. We will describe the protocols as well as the most important read-out parameters including measurement of invasive lung function measurements, serum immunoglobulin levels, isolation of broncho-alveolar lavage fluid (BALF), and preparation of cytospins. Moreover, we describe how to restimulate lung single cell suspensions, perform flow cytometry measurements to identify populations of relevant immune cells, and perform ELISAs and Luminex assays to measure the cytokine concentrations in BALF and lung tissue.

Control of Circulating IgE by the Vitamin D Receptor In Vivo Involves B Cell Intrinsic and Extrinsic Mechanisms

Vitamin D deficiency is associated with the development of asthma and allergy. The active form of vitamin D [1,25(OH)₂D] regulates B cells in vitro and mice without the vitamin D receptor (VDR knockout [KO]) have high serum IgE. Whole-body VDR KO, T cell-specific VDR (T-VDR) KO, B cell-specific VDR (B-VDR) KO, and vitamin D deficient mice were used to determine the targets of vitamin D in the regulation of IgE in vivo. Vitamin D deficient, VDR KO, and B-VDR KO mice developed hyper-IgE, whereas T-VDR KO mice did not. The data show that IL-10 secretion by B cells and CD1d expression on IL-10 secreting B cells was lower in VDR KO mice. Mesenteric lymph node cultures from VDR KO and B-VDR KO mice secreted higher IgE ex vivo than wild-type (WT) cultures, and the addition of IL-10 eliminated the difference in IgE production between VDR KO and WT cultures. The increase in IgE in VDR KO mice was 2-fold greater than in the B-VDR KO mice, suggesting that VDR deficiency in non-B cells contributes to hyper-IgE in vivo. Antibiotic depletion of the microbiota raised serum IgE 4-fold in both WT and VDR KO mice. The VDR directly and indirectly regulates IgE production in B cells. Through the VDR, vitamin D is an environmental factor that helps to maintain low serum IgE responses.

Vitamin D3 improves the effects of low dose Der p 2 allergoid treatment in Der p 2 sensitized BALB/c mice

BACKGROUND

Airborne allergens can induce an immunological chronic disease characterized by airway hyper responsiveness and inflammation, mediated by exaggerated Th2 immune response. Allergen-specific immunotherapy (AIT) is effective for treating this condition because it is able to modify its natural course by opposing the underlying pathogenic mechanisms and determining immune suppression, immune deviation and tolerance. The rational for the present study was to investigate the possibility of improving allergoid-based IT in terms of efficacy and safety. Recently, 1α,25-dihydroxyvitamin D3 (VD3), the active metabolite of vitamin D3, was described to be a potent inducer of T regulatory cells and to be a good adjuvant in AIT settings.

METHODS

We investigated whether the co-administration of VD3 could potentiate the effect of AIT even when added to a low dose of chemically-modified monomeric allergoid of Der p 2 (d2-OID), in a Derp p 2 (d2)-sensitized BALB/c mice model. Control groups where treated with sham, VD3 alone or d2-OID only.

RESULTS

The d2-OID alone was not fully successful, as expected for a low dose. VD3 administration was associated with some valuable, although limited, changes in the immunological parameters in the lung. On the contrary, the VD3 adjuvated allergoid vaccine induced the most prominent reduction of airway eosinophilia and Th2 cytokines and concomitant increase of T regulatory cells and IL-10 in the lung and Der p 2-specific IgG2a in the serum.

CONCLUSIONS

The addition of VD3 to a conventional AIT protocol would allow the reduction of allergoid dose needed and therefore, the production costs. Moreover, beneficial immunomodulatory effects have been achieved by the oral administration which might favour the management of the therapy by the patients and their adherence, possibly enhancing the efficacy of the treatment.

Adalimumab ameliorates OVA-induced airway inflammation in mice: Role of CD4(+) CD25(+) FOXP3(+) regulatory T-cells

Asthma is a chronic inflammatory heterogeneous disorder initiated by a dysregulated immune response which drives disease development in susceptible individuals. Though T helper 2 (TH2) biased responses are usually linked to eosinophilic asthma, other Th cell subsets induce neutrophilic airway inflammation which provokes the most severe asthmatic phenotypes. A growing evidence highlights the role of T regulatory (Treg) cells in damping abnormal Th responses and thus inhibiting allergy and asthma. Therefore, strategies to induce or augment Treg cells hold promise for treatment and prevention of allergic airway inflammation. Recently, the link between Tumor necrosis factor-α (TNF-α) and Treg has been uncovered, and TNF-α antagonists are increasingly used in many autoimmune diseases. Yet, their benefits in allergic airway inflammation is not clarified. We investigated the effect of Adalimumab, a TNF-α antagonist, on Ovalbumin (OVA)-induced allergic airway inflammation in CD1 mice and explored its impact on Treg cells. Our results showed that Adalimumab treatment attenuated the OVA-induced increase in serum IgE, TH2 and TH1 derived inflammatory cytokines (IL-4 and IFN-γ, respectively) in bronchoalveolar lavage (BAL) fluid, suppressed recruitment of inflammatory cells in BAL fluid and lung, and inhibited BAL fluid neutrophilia. It also ameliorated goblet cell metaplasia and bronchial fibrosis. Splenocytes flow cytometry revealed increased percentage of CD4(+) CD25(+) FOXP3(+) Treg cells by Adalimumab that was associated with increase in their suppressive activity as shown by elevated BAL fluid IL-10. We conclude that the beneficial effects of Adalimumab in this CD1 neutrophilic model of allergic airway inflammation are attributed to augmentation of Treg cell number and activity.

Dietary vitamin C deficiency depresses the growth, head kidney and spleen immunity and structural integrity by regulating NF-κB, TOR, Nrf2, apoptosis and MLCK signaling in young grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary vitamin C on the growth, and head kidney, spleen and skin immunity, structural integrity and related signaling molecules mRNA expression levels of young grass carp (Ctenopharyngodon idella). A total of 540 grass carp (264.37 ± 0.66 g) were fed six diets with graded levels of vitamin C (2.9, 44.2, 89.1, 133.8, 179.4 and 224.5 mg/kg diet) for 10 weeks. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila and the survival rate recorded for 14 days. The results indicated that compared with optimal vitamin C supplementation, vitamin C deficiency (2.9 mg/kg diet) decreased lysozyme (LA) and acid phosphatase (ACP) activities, and complement 3 and complement 4 (C4) contents (P < 0.05), down-regulated the mRNA levels of antimicrobial peptides [liver expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, hepcidin, β-defensin] and anti-inflammatory cytokines-related factors, interleukin (IL) 4/13A, IL-4/13B (only in head kidney), IL-10, IL-11, transforming growth factor (TGF) β1, TGF-β2, inhibitor of κBα and eIF4E-binding protein 1 (P < 0.05), and up-regulated pro-inflammatory cytokines-related factors, tumor necrosis factor α, interferon γ2, IL-1β, IL-6, IL-8, IL-12 P35 (only in spleen), IL-12 P40, IL-15, IL-17D, nuclear factor κB p65, IκB kinases (IKKα, IKKβ, IKKγ), target of rapamycin and ribosomal protein S6 kinase 1 mRNA levels (P < 0.05) in the head kidney and spleen under injection fish of A. hydrophila, suggesting that vitamin C deficiency could decrease fish head kidney and spleen immunity and cause inflammation. Meanwhile, compared with optimal vitamin C supplementation, vitamin C deficiency decreased the activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase, glutathione S-transferases and glutathione reductase (P < 0.05), and down-regulated zonula occludens (ZO) 1, ZO-2, Claudin-b, -c, -3c, -7a, -7b, B-cell lymphoma-2, inhibitor of apoptosis protein, NF-E2-related factor 2 mRNA levels (P < 0.05), increased reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl contents (P < 0.05), and up-regulated Claudin-12, 15a, -15b, Fas ligand, mitogen-activated protein kinase kinase 6, p38 mitogen-activated protein kinase, B-cell lymphoma protein 2 associated X protein, apoptotic protease activating factor-1, caspase-3, -7, -8, -9, Kelch-like ECH-associating protein (Keap) 1a and Keap 1b mRNA levels (P < 0.05) in the head kidney and spleen under injection fish of A. hydrophila, suggesting that vitamin C deficiency could decrease fish head kidney and spleen structural integrity through depression of antioxidative ability, induction of apoptosis and disruption of tight junctional complexes. In addition, except the activities of ACP and MnSOD, and mRNA expression levels of TGF-β1, Occludin and MnSOD, the effect of vitamin C on fish head kidney, spleen and skin immunity and structural integrity other indicators model are similar under infection of A. hydrophila. Finally, the vitamin C requirement for the growth performance (PWG) of young grass carp was estimated to be 92.8 mg/kg diet. Meanwhile, the vitamin C requirement for against skin lesion morbidity of young grass carp was estimated to be 122.9 mg/kg diet. In addition, based on the biochemical indices [immune indices (LA activity in the head kidney and C4 content in the spleen) and antioxidant indices (MDA content in the head kidney and ROS content in the spleen)] the vitamin C requirements for young grass carp were estimated to be 131.2, 137.5, 135.8 and 129.8 mg/kg diet, respectively.

Vitamin D and asthma: current perspectives

PURPOSE OF REVIEW

To review the current evidence on the relationship between vitamin D and asthma.

RECENT FINDINGS

The rising morbidity and tremendous socioeconomic burden of asthma have prompted efforts to seek modifiable environmental and nutritional factors that contribute to the asthma epidemic. The association between low levels of vitamin D and asthma has been supported by many, but not all observational and epidemiologic studies. Recently, several controlled clinical trials have been undertaken to explore the effect of vitamin D supplementation on asthma control and respiratory tract infections. While some trials support the beneficial role of vitamin D supplementation in reducing asthma severity in children, several trials have found no beneficial role in adults.

SUMMARY

Given the high prevalence of vitamin D insufficiency in children and adults worldwide and recent randomized controlled trials of vitamin D in asthma, supplementation with vitamin D cannot be recommended as adjunctive therapy for asthma.

Vitamin D Supplementation Reduces Induction of Epithelial-Mesenchymal Transition in Allergen Sensitized and Challenged Mice

Asthma is a chronic disease of the lung associated with airway hyperresponsiveness (AHR), airway obstruction and airway remodeling. Airway remodeling involves differentiation of airway epithelial cells into myofibroblasts via epithelial-mesenchymal transition (EMT) to intensify the degree of subepithelial fibrosis. EMT involves loss in E-cadherin with an increase in mesenchymal markers, including vimentin and N-cadherin. There is growing evidence that vitamin D has immunomodulatory and anti-inflammatory properties. However, the underlying molecular mechanisms of these effects are still unclear. In this study, we examined the contribution of vitamin D on the AHR, airway inflammation and expression of EMT markers in the airways of mice sensitized and challenged with a combination of clinically relevant allergens, house dust mite, ragweed, and Alternaria (HRA). Female Balb/c mice were fed with vitamin D-sufficient (2000 IU/kg) or vitamin D-supplemented (10,000 IU/kg) diet followed by sensitization with HRA. The density of inflammatory cells in the bronchoalveolar lavage fluid (BALF), lung histology, and expression of EMT markers by immunofluorescence were examined. Vitamin D-supplementation decreased AHR, airway inflammation in the BALF and the features of airway remodeling compared to vitamin D-sufficiency in HRA-sensitized and -challenged mice. This was accompanied with increased expression of E-cadherin and decreased vimentin and N-cadherin expression in the airways. These results indicate that vitamin D may be a beneficial adjunct in the treatment regime in allergic asthma.

Deficiency of dietary niacin impaired intestinal mucosal immune function via regulating intestinal NF-κB, Nrf2 and MLCK signaling pathways in young grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary niacin on intestinal mucosal immune and physical barrier, and relative mRNA levels of signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp (255.63 ± 0.41 g) were fed six diets containing graded levels of niacin (3.95, 14.92, 24.98, 35.03, 44.97 and 55.01 mg/kg diet) for 8 weeks. Results observed that niacin deficiency decreased lysozyme (LA) and acid phosphatase (ACP) activities, and complement 3 (C3) content in the intestine (P < 0.05), down-regulated mRNA levels of liver expressed antimicrobial peptide 2 (LEAP-2), hepcidin, interleukin 10, transforming growth factor β1 and inhibitor of κBα (IκBα) (P < 0.05), up-regulated tumor necrosis factor α, interleukin 1β, interferon γ2, interleukin 8, nuclear factor kappa B P65 (NF-κB P65), IκB kinase α (IKKα), IκB kinase β (IKKβ) and IκB kinase γ (IKKγ) in all intestinal segments of young grass carp (P < 0.05). In addition, niacin deficiency increased reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC) contents, decreased glutathione content, and copper/zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferases (GST) and glutathione reductase (GR) activities in the intestine of young grass carp (P < 0.05). Additionally, niacin deficiency decreased mRNA levels of CuZnSOD, MnSOD, GPx, CAT, GST, GR, Claudin b, Claudin 3, Claudin c, Occludin, ZO-1, Claudin 15 and NF-E2-related factor 2 (Nrf2) (P < 0.05), and increased Claudin 12, Kelch-like ECH-associating protein 1a (Keap1a), myosin light-chain kinase (MLCK) and p38 mitogen-activated protein kinase (p38 MAPK) mRNA expression levels in the intestine of young grass carp (P < 0.05), while the mRNA level of Kelch-like ECH-associating protein 1b (Keap1b) did not change (P > 0.05). In conclusion, niacin deficiency decreased intestinal mucosal immune and intestinal physical function, as well as regulated mRNA levels of NF-κB P65, IκBα, IKKα, IKKβ, IKKγ, Nrf2, Keap1a, p38 MAPK and MLCK in the intestine of young grass carp. Based on the broken-line model analysis of intestinal lysozyme activity, the requirement of niacin for young grass carp (255.63 ± 0.41 g) were estimated to be 39.80 mg/kg diet.

Association of myelin peptide with vitamin D prevents autoimmune encephalomyelitis development

Multiple sclerosis is a chronic, inflammatory and demyelinating disease of the central nervous system (CNS). As there is no cure for this disease, new therapeutic strategies and prophylactic measures are necessary. We recently described the therapeutic activity of the association between myelin oligodendrocyte glycoprotein peptide (MOG) and active vitamin D3 (VitD) against experimental autoimmune encephalomyelitis (EAE). The objective of this work was to evaluate the prophylactic potential of this association in EAE. C57BL/6 mice were vaccinated with MOG in the presence of VitD and then subjected to EAE induction. Animals were euthanized 7 and 19days after disease induction and the following parameters were evaluated: body weight, clinical score, inflammatory process in the CNS, amount of dendritic cells (DCs) and regulatory T cells in the spleen and cytokine production by spleen and CNS cell cultures. Vaccination with MOG associated with VitD determined a drastic reduction in clinical score, body weight loss, CNS inflammation, DCs maturation and also in the production of cytokines by CNS and spleen cell cultures. Collectively, our data indicate that this association prevents EAE development. A similar effect from specific self-antigens associated with VitD is expected in other autoimmune conditions and deserves to be experimentally appraised.

Dietary pantothenic acid depressed the gill immune and physical barrier function via NF-κB, TOR, Nrf2, p38MAPK and MLCK signaling pathways in grass carp (Ctenopharyngodon idella)

This study explored the effects of pantothenic acid (PA) on the immune and physical barrier function, and relative mRNA levels of signaling molecules in the gill of grass carp (Ctenopharyngodon idella). The results indicated that compared with optimal PA supplementation, PA deficiency (1.31 mg/kg diet) decreased gill interleukin 10, transforming growth factor β1, inhibitor of κBα (IκBα), eIF4E-binding protein 2, Claudin b and ZO-1 mRNA levels; anti-superoxide anion activity, and activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase, glutathione peroxidase, glutathione reductase and NF-E2-related factor (P < 0.05). Additionally, PA deficiency and excess (75.08 mg/kg diet) decreased gill complement 3 and glutathione contents, lysozyme and acid phosphatase, anti-hydroxy radical, catalase and glutathione S-transferases activities, and liver-expression antimicrobial peptide 2, hepcidin, Claudin 3, Claudin c and Occludin mRNA levels (P < 0.05). Conversely, PA deficiency increased gill reactive oxygen species and protein carbonyl contents, and interferon γ2, interleukin 8, nuclear factor kappa B P65, Claudin 15a, Kelch-like ECH-associating protein 1a and Kelch-like ECH-associating protein 1b mRNA levels (P<0.05). Moreover, PA deficiency and excess increased gill malondialdehyde content, and tumor necrosis factor α, interleukin 1β, IκB kinase α, IκB kinase β, IκB kinase γ, target of rapamycin and ribosomal S6 protein kinase1 p38 mitogen-activated protein kinases and myosin light-chain kinase mRNA levels (P<0.05). In conclusion, PA deficiency decreased immune and physical barrier function, and regulated relative mRNA levels of signaling molecules in fish gill. Based on the quadratic regression analysis of gill lysozyme activity, the optimal PA levels in grass carp (253.44-745.25 g) were estimated to be 36.97 mg/kg diet.

Dietary pantothenic acid deficiency and excess depress the growth, intestinal mucosal immune and physical functions by regulating NF-κB, TOR, Nrf2 and MLCK signaling pathways in grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary pantothenic acid (PA) on the growth, intestinal mucosal immune and physical barrier, and relative mRNA levels of signaling molecules in the intestine of grass carp (Ctenopharyngodon idella). A total of 540 grass carp (253.44 ± 0.69 g) were fed six diets with graded levels of PA (PA1, PA15, PA30, PA45, PA60 and PA75 diets) for 8 weeks. The results indicated that compared with PA deficiency (PA1 diet) and excess (PA75 diet) groups, optimal PA supplementation increased (P < 0.05): (1) percent weight gain (PWG), feed intake and feed efficiency; (2) lysozyme activity, complement 3 content, liver-expressed antimicrobial peptide 2 and hepcidin, interleukin 10, transforming growth factor β1 and inhibitor of κBα mRNA levels in some intestinal segments; (3) activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferases and glutathione reductase, and NF-E2-related factor 2 (Nrf2) mRNA level in the whole intestine; (4) Claudin b, Claudin 3, Claudin c, Occludin and ZO-1 mRNA levels in some intestinal segments of grass carp. Conversely, optimal PA supplementation decreased (P < 0.05): (1) tumor necrosis factor α, interleukin 1β, interferon γ2, interleukin 8, nuclear factor κB P65 (NF-κB P65), IκB kinase α, IκB kinase β, IκB kinase γ and target of rapamycin (TOR) mRNA expression levels in some intestinal segments; (2) reactive oxygen species, malondialdehyde and protein carbonyl contents, and Kelch-like ECH-associating protein 1a, Kelch-like ECH-associating protein 1b in the intestine; (3) Claudin 12, Claudin 15a and myosin light-chain kinase (MLCK) mRNA levels in some intestinal segments of grass carp. In conclusion, optimum PA promoted growth, intestinal mucosal immune and physical function, as well as regulated mRNA levels of signaling molecules NF-κB P65, TOR, Nrf2 and MLCK in grass carp intestine. Based on the quadratic regression analysis of PWG and intestinal lysozyme activity, the optimal PA levels in grass carp (253.44-745.25 g) were estimated to be 37.73 mg/kg and 41.38 mg/kg diet, respectively.

Association of serum 25-hydroxyvitamin D with serum IgE levels in Korean adults

OBJECTIVE

Studies about the association between vitamin D and allergic disease and the immune-modulatory function of vitamin D have increased in the recent years. However, not enough studies have been conducted for concrete conclusion about the association vitamin D and allergy. We investigate the association between serum immunoglobulin E (IgE) and serum 25-hydroxyvitamin D (25(OH)D) levels in Korean adults.

METHODS

We used data of 1969 subjects from the 2010 Korean National Health and Nutrition Examination Survey. Total IgE, Dermatophagoides farinae (Df)-specific IgE, and serum 25(OH)D levels were analyzed. Other variables included sex, age, body mass index, smoking history, and economic status. Adjusted regression analysis was used to examine the independent association of 25(OH)D with serum IgE levels.

RESULTS

When we divided all subjects into four groups according to the serum 25(OH)D level: Q1 (lowest), Q2, Q3, and Q4 (highest), the median TIgE level increased with higher quartiles in the Kruskal-Wallis test (p<0.001). Also, the prevalence of Df sensitization was highest in Q4. Serum vitamin D was positively associated with logarithmic transformed total IgE with base of 10 (LogTIgE) (coefficient (B), 0.011; 95% confidence interval, 0.001-0.021). Furthermore, a positive association between 25(OH)D and LogTIgE was found only in men with Df sensitization, but not in men without Df sensitization and women with/without Df sensitization. However, the mean serum 25(OH)D level was significantly lower in participants who were clinically diagnosed with asthma or atopic dermatitis than participants without a history of asthma or atopic dermatitis, respectively.

CONCLUSION

Serum 25(OH)D levels were positively associated with total IgE levels. Furthermore, the association between serum 25(OH)D and total IgE levels could vary depending on sex or allergic sensitization. But, the mean serum 25(OH)D level was lower in participants with asthma or atopic dermatitis history than participants without history of asthma or atopic dermatitis. Prospective further studies will be required to verify this discrepancy.

Vitamin D and 1,25(OH)2D regulation of T cells

Vitamin D is a direct and indirect regulator of T cells. The mechanisms by which vitamin D directly regulates T cells are reviewed and new primary data on the effects of 1,25 dihydroxyvitamin D (1,25(OH)2D) on human invariant natural killer (iNK)T cells is presented. The in vivo effects of vitamin D on murine T cells include inhibition of T cell proliferation, inhibition of IFN-γ, IL-17 and induction of IL-4. Experiments in mice demonstrate that the effectiveness of 1,25(OH)2D requires NKT cells, IL-10, the IL-10R and IL-4. Comparisons of mouse and human T cells show that 1,25(OH)2D inhibits IL-17 and IFN-γ, and induces T regulatory cells and IL-4. IL-4 was induced by 1,25(OH)2D in mouse and human iNKT cells. Activation for 72 h was required for optimal expression of the vitamin D receptor (VDR) in human and mouse T and iNKT cells. In addition, T cells are potential autocrine sources of 1,25(OH)2D but again only 48-72 h after activation. Together the data support the late effects of vitamin D on diseases like inflammatory bowel disease and multiple sclerosis where reducing IL-17 and IFN-γ, while inducing IL-4 and IL-10, would be beneficial.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

IL-10 and regulatory T cells cooperate in allergen-specific immunotherapy to ameliorate allergic asthma

Human studies demonstrated that allergen-specific immunotherapy (IT) represents an effective treatment for allergic diseases. IT involves repeated administration of the sensitizing allergen, indicating a crucial contribution of T cells to its medicinal benefit. However, the underlying mechanisms of IT, especially in a chronic disease, are far from being definitive. In the current study, we sought to elucidate the suppressive mechanisms of IT in a mouse model of chronic allergic asthma. OVA-sensitized mice were challenged with OVA or PBS for 4 wk. After development of chronic airway inflammation, mice received OVA-specific IT or placebo alternately to airway challenge for 3 wk. To analyze the T cell-mediated mechanisms underlying IT in vivo, we elaborated the role of T-bet-expressing Th1 cells, T cell-derived IL-10, and Ag-specific thymic as well as peripherally induced Foxp3(+) regulatory T (Treg) cells. IT ameliorated airway hyperresponsiveness and airway inflammation in a chronic asthma model. Of note, IT even resulted in a regression of structural changes in the airways following chronic inhaled allergen exposure. Concomitantly, IT induced Th1 cells, Foxp3(+), and IL-10-producing Treg cells. Detailed analyses revealed that thymic Treg cells crucially contribute to the effectiveness of IT by promoting IL-10 production in Foxp3-negative T cells. Together with the peripherally induced Ag-specific Foxp3(+) Treg cells, thymic Foxp3(+) Treg cells orchestrate the curative mechanisms of IT. Taken together, we demonstrate that IT is effective in a chronic allergic disease and dependent on IL-10 and thymic as well as peripherally induced Ag-specific Treg cells.

Vitamin D deficiency is related to thyroid antibodies in autoimmune thyroiditis

INTRODUCTION

It has been known that vitamin D has some immunomodulatory effects and in autoimmune thyroid diseases, vitamin D deficiency was more prevalent. In this study, our aim was to investigate the relationship between thyroid autoantibodies and vitamin D.

MATERIAL AND METHODS

Group 1 and 2 consisted of 254 and 27 newly diagnosed Hashimoto's thyroiditis (HT) and Graves' disease (GD) cases, respectively; age-matched 124 healthy subjects were enrolled as controls (group 3). All subjects (n = 405) were evaluated for 25OHD and thyroid autoantibody [anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-tg)] levels.

RESULTS

Group 2 and group 1 patients had lower 25OHD levels than group 3 subjects 14.9 ±8.6 ng/ml, 19.4 ±10.1 ng/ml and 22.5 ±15.4 ng/ml, respectively (p < 0.001). Serum 25OHD levels inversely correlated with anti-tg (r = -0.136, p = 0.025), anti-TPO (r = -0.176, p = 0.003) and parathormone (PTH) (r = -0.240, p < 0.001). Group 2 patients had higher anti-tg and anti-TPO levels than group 1 and 3 (p < 0.001).

CONCLUSIONS

In this study, we found that patients with autoimmune thyroid disease (AITD) present with lower vitamin D levels and GD patients have higher prevalence. Since we found an inverse correlation between vitamin D levels and thyroid antibody levels, we may suggest that vitamin D deficiency is one of the potential factors in pathogenesis of autoimmune thyroid disorders.