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To cite this article: Benson AA, Toh JA, Vernon N, Jariwala SP. The role of vitamin D in the immunopathogenesis of allergic skin diseases. Allergy 2012; 67: 296-301. Abstract Vitamin D plays key roles in innate and adaptive immunity through the stimulation of Toll-like receptors, increasing pro-inflammatory cytokine production, and possibly enhancing T helper type 2 responses. These mechanisms may explain the growing body of evidence connecting vitamin D to allergic diseases, including asthma, food allergies, and allergic rhinitis. The data relating vitamin D to allergic skin diseases are equivocal with studies linking both high and low vitamin D levels to an increased risk of developing atopic dermatitis. In this paper, we describe the role of vitamin D in the immunopathogenesis of atopic dermatitis and other allergic skin diseases. [ABSTRACT FROM AUTHOR]

The role of cytokines in the accumulation of eosinophil granulocytes in inflamed tissue has been studied extensively during recent years, and these molecules have been found to participate throughout the whole process of eosinophil recruitment. Haematopoietic cytokines such as IL-3, IL-5 and GM-CSF stimulate the proliferation and differentiation of eosinophils in the bone marrow, and the release of mature eosinophils from the bone marrow into the blood is probably promoted by IL-5. Priming of eosinophils in the blood following, for example, allergen challenge is performed mainly by IL-3, IL-5 and GM-CSF. An important step in the extravasation of eosinophils is their adhesion to the vascular endothelium. Adhesion molecules are upregulated by, e.g. IL-1, IL-4, TNF- α and IFN- γ and the same cytokines may also increase the affinity of adhesion molecules both on eosinophils and endothelial cells. Finally, a number of cytokines have been shown to act as eosinophil chemotactic factors, attracting the cells to the inflammatory focus in the tissue. Some of the most important eosinophil chemoattractant cytokines are IL-5, IL-8, RANTES, eotaxin, eotaxin-2, eotaxin-3, MCP-3, MCP-4 and TNF- α. Th2 cells, mast cells and epithelial cells are important sources of proinflammatory cytokines, but in recent years, the eosinophils have also been recognized as cytokine-producing and thereby immunoregulatory cells. The aim of this paper is to review the role of cytokines in the process of eosinophil recruitment in asthma, allergy and ulcerative colitis. [ABSTRACT FROM AUTHOR]

This paper reports the presence of memory T cells in the nasal mucosa of allergic patients. The demonstration of CD4+/CD29+ (CD4+/CD45RO+) T lymphocytes, which are capable of interleukin-4 production, can indicate a complementary cell-mediated regulatory mechanism for mast cell proliferation and IgE synthesis in human nasal allergy. No substantial IgE production can be obtained in the absence of IL-4. Therefore, the existence of IL-4 producing cells on site in the nasal mucosa of allergic subjects probably implies a complementary interaction between cytokines and different immunocompetent nasal cells in the regulation of B cells and IgE synthesis. [ABSTRACT FROM AUTHOR]

The article presents information on abstracts of various research papers to be presented in a conference to be held on September 13, 1993. One of the abstract is on T Cell-derived Cytokines interleukin (IL)-3. IL-3 shares many biological activities with IL-3 induce immunoglobulin (Ig) G4 and IgE synthesis by naive surface human B cells, independently from IL-4. Another abstract is on activation of human neutrophils by airborne particulates. The study conducted in this regard shows that airborne particulates can directly lead to cell activation, shown by the increased release of proinflammatory mediators and by reactive oxygen species production. This study can therefore elucidate the pathomechanism underlying the increased prevalence of airway inflammatory reactions in highly polluted regions.

Symptoms and laboratory parameters of allergic diseases exhibit prominent ~24-h variations. For instance, in most allergic rhinitis patients, symptoms worsen overnight or early in the morning. Accordingly, there are benefits to nighttime dosing of anti-allergy medications in such patients. Although the circadian pathophysiology of allergic diseases is well documented, the biological basis of this phenomenon remains poorly understood. Recent studies have begun to reveal that the internal timekeeping system termed the circadian clock plays a key role in temporal regulation of allergic reaction, and may therefore underlie the circadian pathophysiology of allergic diseases. Here, we review new knowledge that highlights the emerging role of the circadian clock as a potent regulator of allergic reactions. Given the strong influence of circadian rhythms on allergic diseases, we believe that research on how the time of day impacts allergic reaction which we may call 'chronoallergology' will provide new insight into previously unknown aspects of the biology of allergies. Such knowledge should facilitate novel strategies for prevention and treatment of these diseases. [ABSTRACT FROM AUTHOR]

Background: Several studies in mice have recently shown that basophils can act as antigen-presenting cells ( APC) inducing Th2-mediated immune responses against parasites or protease allergens. The aim of this study was to investigate whether human basophils function as APC for the major birch pollen allergen Bet v 1. Methods: Fluorescently labeled Bet v 1 was used to assess surface binding and internalization of allergen by basophils and different types of APC from birch pollen-allergic and nonallergic individuals. Sorted basophils were analyzed in terms of up-regulation of MHC class II and co-stimulatory molecules in the absence and presence of IL-3 and IFN-γ by flow cytometry. Expression of proteins crucial for antigen presentation, namely cathepsin S and invariant chain, was determined. Basophils were used as APC in co-culture experiments with Bet v 1-specific T-cell clones ( TCCs). Results: Basophils from birch pollen-allergic donors very efficiently bound Bet v 1 through Ig E/ Fcε RI complexes on their surface. In contrast to professional APC, basophils did not internalize allergen and expressed marginal levels of cathepsin S and invariant chain. HLA- DP, HLA- DQ, CD80/ CD86, and CD40 were absent from purified basophils even when stimulated with IL-3 plus IFN-γ. IL-3/ IFN-γ marginally up-regulated HLA- DR. Bet v 1-pulsed basophils failed to induce proliferative and cytokine responses in Bet v 1-specific, HLA- DR-restricted TCCs. Conclusion: Human basophils neither internalize, process nor present Bet v 1. Because Bet v 1 is a highly relevant allergen, we conclude that basophils play no role as APC in Ig E-mediated allergy in humans. [ABSTRACT FROM AUTHOR]

Background: Regulatory T cells ( Tregs) with stable FOXP3 expression are characterized by a specific demethylated region in the FOXP3 gene ( Treg-specific demethylated region, TSDR). The aim of this study was to analyse the influence of prenatal factors on cord blood Treg numbers, as detected by changes in the TSDR demethylation, and the subsequent risk for allergic diseases. Methods: Analyses were performed within the LINA study in blood samples from pregnant women (34th gestational week) and in cord blood ( n = 346 mother-child pairs). Treg numbers were detected via DNA demethylation in the FOXP3 TSDR. At age 1, total and specific Ig E was measured in children's blood. In addition, maternal cytokine production ( Th1/ Th2/ Th17) was analysed. Exposure and disease outcomes were assessed by questionnaires. Results: Boys had lower Treg numbers compared with girls ( P < 0.001). Parental atopy history, particularly maternal hay fever and paternal asthma were related to lower Treg numbers in cord blood (adj. MR = 0.81, 95% CI = 0.68-0.97; adj. MR = 0.60, 95% CI = 0.45-0.81). Maternal cytokines ( IL-13, IL-17 E and IFN-γ) and maternal smoking/exposure to tobacco smoke during pregnancy were also associated with decreased cord blood Treg numbers (adj. MR = 0.89, 95% CI = 0.97-1.00). Children with lower Treg numbers at birth had a higher risk to develop atopic dermatitis (adj. OR = 1.55, 95% CI = 1.00-2.41) and sensitization to food allergens (adj. OR = 1.55, 95% CI = 1.06-2.25) during the first year of life. Conclusions: These results indicate that both genetic and environmental factors presumably influence the development of foetal Tregs. Low cord blood Treg numbers may predict early atopic dermatitis. [ABSTRACT FROM AUTHOR]

Background: Co-vaccination with cellular pertussis vaccine down-regulates allergic sensitization to diphtheria and tetanus antigens. Using a murine model, we investigated whether vaccination with diphtheria/tetanus toxoids, administered separately or simultaneously with the whole cell vaccine of Bordetella pertussis, inhibits subsequent allergen-induced immune and inflammatory responses. Methods: BALB/c-mice were vaccinated intracutaneously with a combination of diphtheria and tetanus toxoids or a combination of diphtheria and tetanus toxoids with a whole cell vaccine of B. pertussis (three times, days −21 to −7) prior to systemic sensitization (days 1–14) and repeated airway challenges (days 28–30) with ovalbumin. Results: Compared with negative controls, systemic sensitization and airway allergen challenges induced high serum levels of allergen-specific IgE, predominant Th2-type cytokine production, airway inflammation and development of in vivo airway hyperreactivity. Vaccination with diphtheria and tetanus toxoids prior to sensitization suppressed IgE formation and development of eosinophilic airway inflammation. Co-vaccination with a whole cell pertussis vaccine inhibited allergen sensitization, airway inflammation and development of in vivo airway hyperreactivity. Prevention was due to an allergen-specific and general shift from a predominant Th2 towards a predominant Th1 immune response. Conclusion: Vaccination with diphtheria and tetanus toxoids alone or in combination with whole cell pertussis vaccine prior to allergen sensitization prevented allergen-induced Th2 immune responses. Vaccine antigens may down-regulate allergic responses to a range of common allergens. [ABSTRACT FROM AUTHOR]

Background: Allergic diseases have become a major public health problem in developed countries; yet, no reliable, safe and consistently effective treatment is available. DNA immunization has been shown to prevent and balance established allergic responses, however, the high dose of conventional DNA vaccines necessary for the induction of anti-allergic reactions and their poor immunogenicity in primates require the development of new allergy DNA vaccines. We evaluated protective and therapeutic effects of a Semliki-Forest Virus replicase-based vs a conventional DNA vaccine in BALB/c mice using the model allergen β-galactosidase. Methods: Immunoglobulin (Ig)E suppression was determined by a basophil release assay as an in vitro correlate for allergen-specific crosslinking capacity of IgE reflecting the in vivo situation in an allergic individual. Th1 memory responses were measured by cytokine detection via enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT). Results: Nanogram amounts of a replicase-based vector triggered a Th1 response comparable with that achieved with the injection of 20 000-times more copies of a conventional DNA plasmid, and induced IgE suppression in both a protective and a therapeutic setting. Conclusions: Replicase-based DNA vaccines fulfill the stringent criteria for an allergy DNA vaccine, i.e. low dose, strong Th1 immunogenicity and memory, lack of ‘therapy-induced’ IgE production and anaphylactic side effects. Moreover, by triggering apoptosis in transfected cells, their unique ‘immunize and disappear’ feature minimizes the hypothetical risks of genomic integration or induction of autoimmunity. [ABSTRACT FROM AUTHOR]

We have entered a new phase in the evolution of our understanding of the role of the eosinophil with a greater appreciation of novel potential functions that may be ascribed to this enigmatic cell type. This review not only provides an update to our current understanding of the various immunobiological roles for the eosinophil, but also attracts attention to some novel observations predicting functions beyond its putative effector role. These observations include the intriguing possibility that the eosinophil may posses the capacity to regulate the immune and inflammatory responses in diseases such as asthma. [ABSTRACT FROM AUTHOR]

Background: Hydrolyzed milk formulas are recommended to feed infants at high risk of atopy if breast-feeding is not possible. We studied the specific cellular and humoral immune response to cow's milk proteins and occurrence of atopic dermatitis under different feeding regimens: two hydrolyzed infant milk formulas (partially [pHF] and extensively hydrolyzed [eHF]) and under exclusive breast-feeding (BF). Methods: Seventy-two infants from families with atopic symptoms were randomized in the pHF and eHF groups, respectively. At 6 and 12 months of age, peripheral blood mononuclear cell proliferation along with specific IgG and IgE to cow's milk proteins was determined in infants fed pHF or eHF, respectively, and those who had not yet received any formula at 6 months of age (BF). Cases of atopic dermatitis were recorded throughout the first 12 months of life, and their severity was evaluated with SCORAD points. Results: A significantly decreased proliferation to cow's milk caseins was found in the pHF group compared to the exclusively breast-fed group. Medians of stimulation indexes for CAS at 6 months were as follows: pHF 1.18; n=24; BF 1.70; n=24 (P=0.033, Mann-Whitney U-test). Higher levels of plasma IgG antibodies to BCAS were found in infants fed pHF than in those fed eHF at 12 months. Optical density (OD): (25th percentile; median; 75th percentile): pHF: 0.00; 0.14; 0.38; n=30; eHF: 0.00; 0.03; 0.14; n=28; P=0,089, Mann-Whitney U-test. Cow's milk-specific IgE was detected at 6 months as follows: BF: 3 of 24; eHF: 2 of 21; pHF: 0 of 23. The number of cases of atopic dermatitis and their severity did not differ among the groups during the first 12 months. Conclusions: Feeding pHF appears to suppress cow's milk-specific cellular responses and stimulate specific IgG production. Specific IgE sensitization can occur also with breast-feeding. [ABSTRACT FROM AUTHOR]

In 4 inbred strains of guinea pig the tendency to develop peripheral high-eosinophilia was shown to be genetically controlled. The development of eosinophilia with age and following immunization was examined in high- and low-eosinophilic parental strains, in F1-hybrids and in backcross offspring. The results show that probably only one or a very few segregating genes control eosinophilia, and they also indicate that different genes are involved in the determination of spontaneous (age-related) and immunization-induced eosinophilia. [ABSTRACT FROM AUTHOR]

The Multitest CMI system consists of a disposable multiple puncture device that simultaneously applies seven standardized recall antigens for assessment of cell-mediated immunity (CMI). The seven antigens included were toxoid from Clostridium tetani and Corynebacterium diphtheriae, tuberculin, plus antigens from streptococcus (group C), Candida albicans, Trichophyton mentagrophytes, and Proteus mirabilis. A population of 352 healthy Danish adults, aged between 17 and 90 years, was tested to determine the incidence and size of delayed-type hypersensitivity (DTH) responses. All but six healthy adults (98%) responded to one or more antigens, the median number of positive responses being four in males and three in females. The incidence of positive responses ranged from 91% for tuberculin to 11% for trichophyton. The number of positive responses declined with age, being somewhat faster in females than males. Six of the seven antigen response rates were significantly lower in the over 65-years-olds, the only exception being trichophyton, and for four of the seven antigens significantly lower in females compared to males. When correlated to age and sex no major differences were found with regard to the size of response to the seven antigens except that the tuberculin response was larger in males. A scoring system based on both number and size of positive responses revealed significant age and sex related differences. The median "score" in 17-65-year-old males and females were, respectively, 17 mm and 14 mm compared to 13 mm and 8 mm in those over 65 years old (P < 0.001 for both comparisons). [ABSTRACT FROM AUTHOR]

A number of studies, primarily in animals, corroborate clinical experience that the allergic inflammatory reaction is more complicated from an immunological point of view than previously appreciated. Allergic inflammation is a consequence of an interplay between various components of the immune system including IgE antibody formation and regulation thereof. IgG antibodies and complement, cell-mediated immune reactions and lymphokines as well as immune regulation of the proliferation and differentiation of mast cells, basophils and mucous cells.

Rats of BNxWi/Fu strain were immunized by daily subcutaneous (s.c.) injections of antigen without the use of adjuvant for two 2-week periods with a 4-week interval. The bronchial responses to airway and intravenous (i.v.) antigen challenge were measured during and after the immunization period. These responses were compared with both the humoral and the cell-mediated immune response of the animals, immunization induced bronchial reactivity of the animals to antigen after airway and i.v. challenge. This reactivity persisted for 7 weeks following the second immunization period. Specific IgE antibodies were detected in serum, bronchial fluid and in supernatants from cultured peripheral lymph node cells. The immunisation also resulted in an IgG antibody response. Neither the amount of IgE. IgG2a, nor of any other isotype. correlated with the bronchial reactivity in the animals. Antigen stimulation of lymph node cells mixed with syngeneic spleen cells induced proliferation. This procedure also resulted in a maturation of mast cells in 3-week cultures. The immunization also resulted in some increase in the number of mast cells around vessels in the lung. There was no correlation between these parameters of cell-mediated immunity and either antibody responses or bronchial reactivity. [ABSTRACT FROM AUTHOR]

Dong dander and hair (DDHP specific IgA and IgG antibodies form serum samples of 202 asthmatic children aged from 4 to 15 years were measured by enzyme-linked immunosorbend assay. The results were compared with clinical history, and with allergy tests (skin prick test, provocation test and RAST) using the same DDH extract. A blood sample for the in vitro lymphocyte stimulation test was obtained from 40 children, and a nasal secretion sample for analysis of the local DDH-specific IgA, IgG and IgE antibody levels was collected from 35 of them. In children of dog-keeping families, higher serum levels of DDH-specific antibodies, especially IgE antibodies, were observed if the dog had been in the home already during the first years of the child's life. The serum levels of DDH-specific antibodies, however, did not correlate with the degree of the present exposure to dogs. The serum levels of DDH-specific IgA and IgG antibodies did not correlate with each other with the levels of specific or total IgE, or with the results of skin prick or provocation test. The serum levels of DDH-specific IgE correlated positively with serum specific IgE levels. The correlation was weaker between nasal and serum titers of specific IgG, and not significant between nasal and serum IgA antibody levels. Specific IgE antibody levels were higher, while specific IgA and IgG antibody levels were lower in nasal secretion from subjects with nasal symptoms on contact with dogs, when compared with subjects with other complaints (asthma, conjunctival or skin reactions). DDH-specific IgG levels correlated negatively with specific IgE level in the nasal secretion from subjects with a positive provocation test. The in vitro lymphocyte responses to DDH did not correlate with the results of allergy tests, or with the levels of DDH-specific antibodies in serum or in nasal secretion. [ABSTRACT FROM AUTHOR]

The principle of treating allergic diseases by injection of increasing amounts of the allergen causing the symptoms has been used for almost a century (1). Specific immunotherapy (SIT) for IgE-mediated allergy has been shown to be effective in reducing symptoms of hay fever and asthma in selected patients and even more so in venom anaphylaxis (2). The study of the mechanisms of SIT has served as a model to gain insight into the immunologic changes associated with allergic diseases, and is also a prerequisite for improving the efficacy and safety of SIT. For many years, the focus has been on the changes in the specific immunoglobulins IgE and IgG during SIT, but the last decade has directed attention to the changes in T-cell responses and cytokines (3-8). [ABSTRACT FROM AUTHOR]