s a new epidemic of the 21st century1 causing growing selleck bio health problems, particularly in industrialized countries, atopic diseases such as hay fever, bronchial asthma, and atopic dermatitis call for the development of innovative primary prevention concepts. Pathophysiology of allergic diseases is based on extreme T helper 2 immune responses to commonly harmless environmental antigens. The key cytokines interleukin 4 and IL 13 induce immunoglobulin class switch in B cells, leading to excessive IgE production with subsequent mast cell activation and mediator release, and IL 5 contributes to development of eosinophilic inflam mation and enhances mucus production of the airway epithelia. The reasons for dysregulation and the resulting imbalance in cellular immune responses on allergens are still not certainly identified.

Genetic predisposition, especially genegene interactions,3 seems to be a fundamental factor but does not explain the extensive increase in the incidence and prevalence of atopic diseases within the last 40 years. Numerous environmental triggers Inhibitors,Modulators,Libraries might account for this increase, such as altered climate conditions with increasing global warming, resulting Inhibitors,Modulators,Libraries in lengthened pollen seasons and thus increased exposure to environmental allergens, or lifestyle factors, such as improved hygiene. 4 Simple allergen avoidance for primary prevention of allergy appeared not to be practical or sufficient,5 and present antiphlogistic therapies with antihistamines or steroids just diminish symptoms for a short time but potentially cause side effects and are not curative.

6 New immunomodulatory strategies aim to support naturally occurring regulatory mechanisms that may protect against predominant Th2 immune responses and maintain the immunologic balance, thus preventing the development of allergen sensitization as the first step of the atopic march in high risk children. 7 Most of these new methods are Inhibitors,Modulators,Libraries currently under experimental investigation, and only a few have already been employed in humans. The present review provides an overview of these various immunomodulatory strategies and their principal mechanisms. Th1Th2 Concept Center of Immunomodulatory Prevention Inhibitors,Modulators,Libraries Strategies Polarization of the adaptive cellular immune response Inhibitors,Modulators,Libraries is based on antigen presentation by dendritic cells or other antigen presenting cells that leads to differentiation of naive CD4 T cells into Th1 or Th2 effector cells. Immature 17-AAG skin or mucosa associated DCs phagocytize a foreign antigen on its entry site and migrate via blood and lymph to secondary lymphatic organs while they are differentiating to mature APCs.