Immunoglobulin E (IgE) is an immunoglobulin, which plays a central role in acute allergic reactions and chronic inflammatory allergic diseases. Specifically, it is one of the five immunoglobulins (A, G, M, D, and E). IgE monomer contains two heavy chains: ε and two light chains. Besides, IgE is an important component of the immune response to certain parasitic infections. Moreover, IgE is also used for immune defense against some protozoan parasites, such as Plasmodium falciparum. Furthermore, IgE also plays an important role in the reaction to allergens.

Particularly, IgE can be expressed in mast cells and basophils by a protein FCε The high-affinity receptor of RI binds to effector cells. Interestingly, it mediates allergic reactions by interacting with its two receptors, FC, the high-affinity receptor of FcϵRI and low-affinity receptor CD23. CD23 plays a role in the feedback regulation of IgE mediated antigen presentation and IgE antibody production. After contact with a specific antigen, the allergen binds to IgE and crosslinks IgE/FcϵRI complex. Then trigger the release of inflammatory mediators, and then induce a variety of allergic symptoms. One way to control allergic diseases is to develop monoclonal antibodies that bind to IgE. Then, we will introduce a humanized, monoclonal antibody against human IgE, Omalizumab.

Omalizumab is an Antibody against human IgE for Persistent Allergic Asthma Research.

In the first place, Omalizumab is a recombinant, humanized, monoclonal antibody against human IgE with a K_D of 0.393 nM. Meanwhile, Omalizumab binds to the human FcγRIIb receptors with a K_D of 6.37 uM. Nonetheless, Omalizumab has the potential for persistent allergic asthma research.

Next in importance, Omalizumab with 0.1-2.0 μg/mL has a direct effect on the B cells. Obviously, Omalizumab can reduce the number of membrane IgE+ cells present in IL-4 plus anti-CD40 treated B cell cultures. Importantly, Omalizumab alone has no effect on the viable cell number. Omalizumab reduces IL-6 secretion in human B cells. Additionally, Omalizumab does not induce apoptosis in human B cells

Once more, Omalizumab with 10 mg/kg/day by ip on day 8 to 42 increases IgE levels in human PBMC-engrafted severe combined immunodeficiency (huSCID) mice.

All in all, Omalizumab is a monoclonal antibody against human IgE for persistent allergic asthma research.

References:

Peipei Liu, et al. Front Immunol. 2020 Nov 27;11:596908.

Marcia A Chan, et al. Clin Transl Allergy. 2013 Sep 2;3(1):29.