It is not clear why some individuals with allergen-specific IgE suffer from allergies, while others do not. It is
likely that multiple factors contribute, including differences in IgE affinity or epitope diversity for allergens, mast
cell numbers, FceRI expression levels, Syk signaling, allergen-specific IgG antibodies, and anti-IgE antibodies.
An addition factor that has not been considered is the contribution of glycosylation to IgE. Our long-term goal is
to understand how glycosylation of antibodies regulates, and is regulated, by immune responses. Our central
hypothesis is that IgE effector function is regulated differentially by defined glycans at distinct positions.
Indeed, this is supported by preliminary data shown in this application. The rationale that underlies the
proposed research is that understanding the contribution of specific IgE glycans to allergic inflammation will
enable new and innovative allergic therapies. We will test our central hypothesis and, thereby, attain the
objective of this application by pursuing the following three specific aims: 1) Define the IgE glycan
requirements for FceRI binding; 2) Determine how sialic acid regulates IgE-mediated anaphylaxis; 3) Examine
the regulation of IgE glycosylation in vivo. Using an approach that combines biophysics, cellular and molecular
immunology, and glycobiology, we will determine glycans a essential for IgE-FceRI interactions, define a novel
anti-anaphylactic pathway, establish pathogenic IgE glycosylation patterns, and attenuate anaphylaxis by
modulating IgE glycans. In addition to enabling discovery of biomarkers marking allergy-causing IgE, the
studies here will potentially result in identification of novel therapeutic targets for allergic disease. Finally, these
studies will have impact beyond allergy in diseases in which IgE is involved, including systemic lupus
erythematosus (SLE) and helminth infection.