LIFE SCIENCE

Detailed explanation-1: -The low-affinity IgE receptor, FcRII (CD23), is a Ca-dependent lectin that is expressed on B cells, as well as T cells, Langerhan cells, macrophage, monocytes, eosinophils, and platelets.

Detailed explanation-2: -Allergen-specific TH2 cells produce IL-4 and IL-13, which drive allergen-specific B cells to produce IgE. The specific IgE produced in response to the allergen binds to the high-affinity receptor for IgE on mast cells, basophils, and activated eosinophils.

Detailed explanation-3: -IgE binds to two types of Fc receptors, called Fc epsilon R1 (or high-affinity Fc epsilon R) and Fc epsilon R2 (or low-affinity Fc epsilon R). The Fc epsilon R1 is composed of four polypeptide chains, one alpha, one beta, and two gamma chains.

Detailed explanation-4: -Omalizumab binds to serum free IgE and reduces IgE serum concentration, but does not bind to high-or low-affinity IgE receptors on inflammatory cells. However, it blocks IgE binding to these receptors and the IgE effector cells of inflammation are “disarmed”.