Abstract
The α-Gal epitope is an immunogen trisaccharide structure consisting of N-acetylglucosamine (GlcNAc)β1,4-galactose (Gal)α1,3-Gal. It is presented as part of complex-type glycans on glycoproteins or glycolipids on cell surfaces of non-primate mammalians. About 1% of all antibodies in human sera are specific toward α1,3-Gal and are therefore named as anti-α-Gal antibodies. This work comprises the purification and characterization of anti-α-Gal antibodies from human immunoglobulin G (IgG). A synthetically manufactured α Gal epitope affinity resin was used to enrich anti-α-Gal antibodies. Selectivity experiments with purified antibodies were carried out using enzyme-linked immunosorbent assays (ELISA), Western blotting, and erythrocyte agglutination. Furthermore, binding affinities toward α-Gal were determined by surface plasmon resonance (SPR) and the IgG distribution of anti α Gal antibodies (83% IgG2, 14% IgG1, 2% IgG3, 1% IgG4) was calculated applying ELISA and immunodiffusion. A range of isoelectric points from pH 6 to pH 8 was observed in 2D gel electrophoresis. Glycan profiling of anti α Gal antibodies revealed complex biantennary structures with high fucosylation grades (86%). Additionally, low amounts of bisecting GlcNAc (15%) and sialic acids (13%) were detected. The purification of anti-α-Gal antibodies from human IgG was successful, and their use as detection antibodies for α Gal-containing structures was evaluated.
Highlights
The α-Gal epitope is an immunogen glycan antigen composed of the structure Nacetylglucosamine (GlcNAc)β1,4-galactose-(Gal)α1,3-Gal [1,2]
Up to 1% of all immunoglobulin G (IgG) antibodies in human sera show selectivity toward α1,3-Gal on glycoproteins [10,11,12,13] and glycolipids [14,15,16]
After washing with phosphate-buffered saline (PBS), bound anti-α-Gal antibodies were competitively eluted by 500 mM Gal
Summary
The α-Gal epitope is an immunogen glycan antigen composed of the structure Nacetylglucosamine (GlcNAc)β1,4-galactose-(Gal)α1,3-Gal [1,2]. Galili et al conducted pioneer research in terms of purification and selectivity analysis of anti-α-Gal antibodies They discovered anti-α-Gal producing B-cells in lymphoid tissue along the gastrointestinal tract [19]. The location of patients with high titers of anti-cetuximab IgE antibodies geographically overlapped with regions of reported “red meat allergy” [31,32,33,34]. This allergy could be linked to tick bites by Amblyomma americanum, known as Lone Star tick [35,36,37,38,39]. Increased activity of the immune system has already been identified on the mouse model using α-Gal-coated influenza virus [40]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
