mutations in filaggrin) that render the host susceptible to allergen contact and entry and elicit direct or indirect stress in the epithelial barrier, particularly in the skin or intestinal mucosa. Open in a separate window Figure 1 The barrier regulation hypothesis of allergic disease(A) In healthy individuals, both food allergen specific and bacteria-induced Tregs cooperate with ILC-derived IL-22 dependent effector functions (e.g. approaches to prevention and treatment. Intro The prevalence of allergic disease offers climbed steadily during the past fifty years BDA-366 (Asher et al., 2006; Okada et al., 2010). Its medical demonstration often follows an ordered developmental progression (atopic dermatitis, food allergy, asthma, allergic rhinitis) referred to as the allergic march (Alduraywish et al., 2015). Epidemic raises in asthma prevalence were the first to gain notice (Eder et al., 2006; Masoli et al., 2004). More recently, potentially life-threatening allergic reactions to food have become an important public health concern (Prescott and Allen, 2011; Sicherer and Sampson, 2014). Nut-free classrooms, virtually unheard of in earlier decades, BDA-366 are now commonplace. In developed countries worldwide, as many as 10% of preschool children currently suffer from food allergies (Prescott et al., 2013). Recent reports estimate that there are 15 million children and adults with food allergies in the United States only (Branum and Lukacs, 2008; Jackson et al., 2013). While hundreds of foods can elicit an allergic response (Hefle et al., 1996), eight in particularnamely, milk, eggs, peanuts, tree nuts, wheat, soy, fish and shellfishaccount for most instances (Sicherer and Sampson, 2014). Genetic susceptibility cannot clarify a marked increase in prevalence in such a short time framework, suggesting that something about our modern environment is advertising allergic disease. We begin this review with a brief history of allergy, focusing on IgE-mediated hypersensitivity, and describe emerging concepts concerning its potential physiologic functions. We then discuss recent data that point to early existence as an important time where environmental contextparticularly with regard to the microbiotainfluences susceptibility to allergic disease. We end with some remarks on how recent findings will inform the development of novel therapeutic strategies to prevent or treat food allergy along with other allergic diseases. Why does allergy exist? The term allergy was coined in 1906 from the Viennese pediatrician Baron Clemens von Pirquet from your Greek allos indicating other or modified and ergon indicating works or reaction. Von Pirquet observed that changes in Rabbit polyclonal to ubiquitin reactivity occurred on subsequent exposures to an antigen. In some instances, re-exposure resulted in diminished reactivity whereas in others reactivity improved (Igea, 2013). A major advance in the understanding of food allergy occurred in 1921, when Prausnitz and Kustner identified that hypersensitivity to an antigen could be passively transferred with serum from one individualnamely, Kustner, who was allergic to fishto anothernamely, Prausnitz, who was not allergic to fishby intradermal injection. When Prausnitz consequently ate fish, the injection site became sizzling, red, and inflamed (Prausnitz and Kustner, 1921). The antigens responsible for this reaction were called atopens, and the plasma element that conferred level of sensitivity was known as atopic reagin (Paul, 2013). In 1966, Teruko and Kimishige Ishizaka showed that a novel class of immunoglobulin (Ig), which they designated E-globulin, or IgE, was responsible for reaginic activity (Ishizaka and Ishizaka, 1966). Since the finding of IgE, much concerning the molecular and cellular mechanisms by which allergens elicit medical symptoms has been elucidated. However, little insight has been gained into why allergies exist in the first place. One hypothesis common in the current literature suggests that Th2 immunity developed to facilitate the removal of worms and parasites and that allergy represents a misfiring of this response to normally innocuous substances (Fitzsimmons and Dunne, 2009; Pulendran and Artis, 2012; Stetson et al., 2004). The mind-boggling majority of allergens are not, however, helminths or their products. The major allergens are a varied group for which nobody structural or biological activity appears to dominate, and include proteins associated with shellfish, nuts, venoms, BDA-366 pollens, animal dander, and penicillin (Erwin and Platts-Mills, 2005). It is hard to conceptualize, that within an immune system.