The Oettgen lab research is centered on three main areas 1) Regulation of Immune Responses by IgE Antibodies: We and others have recently observed that IgE antibodies can exert effects on many other aspects of the immune response. We aim to define the biological effects of monomeric IgE and understand their implications for allergic pathogenesis. 2) Immunobiology of Eczema Vaccinatum: Eczema vaccinatum (EV) is a severe, overwhelming infection to the vaccine strain, vaccinia virus, contained in small pox vaccine which can occur in patients with eczema (atopic dermatitis). Recent concerns regarding the potential use of small pox as a bioterror agent have led the National Institutes of Allergy and Infectious Diseases of the National Institutes of Health to convene a consortium of researchers to study the mechanisms whereby allergic inflammation of the skin predisposes to such an abnormal response to the virus. 3) Basophils in Early Responses to Allergens: IgE production and tissue inflammation in allergic individuals is driven by the cytokine, IL-4. IL-4 is produced by Th2 T helper cells present at allergic sites. The expansion of Th2 cells during allergic responses is IL-4 driven itself raising a ?chicken and egg? Dilemma of where the first IL-4 comes from in allergic tissues. We have recently observed that a rare circulating leukocyte, the basophil, is rapidly recruited immediately following allergen exposure and produces abundant IL-4. We are now testing whether IL-4 producing basophils are the key instigators of Th2-driven allergic responses following mold inhalation in a mouse asthma model.