IgE Protein, Human (322a.a, HEK293, His)

The IgE protein, a crucial component of immunoglobulins, functions in both the recognition and effector phases of humoral immunity. Serving as a membrane-bound receptor on B lymphocytes during the recognition phase, IgE plays a pivotal role in triggering clonal expansion and differentiation into immunoglobulin-secreting plasma cells upon specific antigen binding. In the effector phase, secreted IgE mediates immune responses through two Fc receptors, FCER1A:MS4A2:FCGR1A and FCER2, which, upon antigen cross-linking, initiate signaling pathways leading to immune cell activation. IgE facilitates immediate hypersensitivity responses against allergens and defends against helminth parasites, bacteria, and venom toxicity. Dysregulation can lead to harmful allergic reactions and anaphylaxis. IgE stimulates mast cells, basophils, and eosinophils to release inflammatory mediators, contributing to tissue remodeling and cytotoxicity against microbes. On macrophages, IgE induces intracellular killing of parasites and activates antitumor functions, including antibody-dependent cytotoxicity and proinflammatory responses. Additionally, IgE plays a role in B cell antigen uptake and presentation to T cells.