Binding of Griffonia simplicifolia 1 isolectin B4 (GS1 B4) to α‐galactose antigens

Abstract

SummaryGlycoconjugates with terminal Galα1-3Galβ1-4GlcNAc sequences (α-galactosyl epitopes, natural xenoreactive antigens) are present on various tissues in pigs and are recognized by human anti-αgalactosyl (αGal) antibodies 1 . Hence xenotransplantation (pig-to-human) would trigger immune reactions involving complement activation and lead to the hyperactute rejection of the graft. Xenoreactive antigens are often studied by using the lectin Griffonia simplicifolia 1 isolectin B4 (GS1 B4), which shows high affinity to galactose. We here estimate the specificity of GS1 B4 for detecting various galactosyl epitopes by measuring lectin binding to neoglycoproteins, thyroglobulin and pig skeletal muscle. Enzyme linked lectin assays confirmed that GS1 B4 was highly specific to α-galactosylated neoglycoproteins while the lectin did not detect a β-galactosylated ligand. The length of the sugar chains influenced the lectin-carbohydrate interaction. A monosaccharide linked to serum albumin showed higher lectin affinity than did neoglycoproteins with di-and tri-α-galactosyl epitopes. When the carbohydrate was extended, as in the xenoreactive pentasaccharide (Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glc), the carbohydratelectin interaction was meagre. Not only the terminal, but also the subterminal sugar affected the lectin binding because the GS1 B4 affinity to Galα1-3Gal was much stronger than to Galα1-3GalNAc. In bovine and porcine thyroglobulin most αGal epitopes appear to be cryptic, but are unmasked by a heat denaturation. In pig skeletal muscle there was lectin reaction not only in the muscle capillaries, but also in the connective tissue and intracellularly in muscle fibres. In Western blots of isolated proteins from pig muscle at least three bands were strongly stained after incubation with lectin.

Femtosecond laser-assisted conjunctival autograft preparation for pterygium surgery

“…In our ultra-thin 60 µm CAGs, we were able to demonstrate the persistence of small and midsize stromal vessels by immunohistochemistry ( Figure 5). While the isolectin-B4 glycoprotein originally isolated from the seeds of the tropical African legume Griffonia simplicifolia has proven high affinity to porcine perivascular and vascular endothelial cells, 22 it has also been shown to interact with other cell types such as neurons or epithelial cells, 35 which also occurred in our sections.…”

Levels of Cocaine- and Amphetamine-Regulated Transcript in Vagal Afferents in the Mouse Are Unaltered in Response to Metabolic Challenges

“…In the past, isolectin B4 binding to C-fiber neurons has been commonly used to trace the perikarya and central axons of C-fiber neurons (Fang et al, 2006; Fullmer et al, 2007; Solorzano et al, 2015). However, because of extraneuronal binding (Kirkeby and Moe, 2001), isolectin B4 does not permit the labeling of axons that innervate peripheral tissues. In addition, numerous developmental, biological, and inflammatory factors influence isolectin B4 binding to sensory neurons (Beland and Fitzgerald, 2001; Fullmer et al, 2007); Therefore, it is possible that isolectin B4 binding to C-fibers may vary in response to different physiological conditions.…”

Generation of GGTA1 biallelic knockout pigs via zinc-finger nucleases and somatic cell nuclear transfer

“…Isolectin B4 shows high affinity toward alpha galactose on cell membranes [22,23]. Hence, FITC-conjugated isolectin B4 was used to detect Gal epitopes of GGTA1 mutant porcine cells.…”