Characteristics of α-Gal epitope, anti-Gal antibody, α1,3 galactosyltransferase and its clinical exploitation (Review)

作者：Guoli Huai, Ping Qi, Hongji Yang, Yi Wang · 发表于：International Journal of Molecular Medicine · 年份：2015 · DOI：10.3892/ijmm.2015.2397 · 被引用次数：84 · 研究领域：Xenotransplantation and immune response、Animal Genetics and Reproduction、Virus-based gene therapy research

The α-Gal epitope (Galα1,3Galα1,4GlcNAc‑R) is ubiquitously presented in non-primate mammals, marsupials and New World Monkeys, but it is absent in humans, apes and Old World monkeys. However, the anti-Gal antibody (~1% of immunoglobulins) is naturally generated in human, and is found as the immunoglobulin G (IgG), IgM and IgA isotypes. Owing to the specific binding of the anti‑Gal antibody with the α‑Gal epitope, humans have a distinct anti‑α‑gal reactivity, which is responsible for hyperacute rejection of organs transplanted from α‑gal donors. In addition, the α1,3 galactosyltransferases (α1,3GT) can catalyze the synthesis of the α‑Gal epitope. Therefore, the α1,3GT gene, which encodes the α1,3GT, is developed profoundly. The distributions of the α‑Gal epitope and anti‑Gal antibody, and the activation of α1,3GT, reveal that the enzyme of α1,3GT in ancestral primates is ineffective. Comparison of the nucleotide sequence of the human α1,3‑GT pseudogene to the corresponding different species sequence, and according to the evolutionary tree of different species, the results of evolutionary inactivation of the α1,3GT gene in ancestral primates attribute to the mutations under a stronger selective pressure. However, on the basis of the structure, the mechanism and the specificity of the α‑Gal epitope and anti‑Gal antibody, they can be applied to clinical exploitation. Knocking out the α1,3GT gene will eliminate the xenoantigen, Gal(α1,3)Gal, so that the transplantation of α1,3GT g...