Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States.
Glycobiology. 2023 Dec 25;33(11):879-887. doi: 10.1093/glycob/cwad083.
Protein-carbohydrate interactions are essential in maintaining immune homeostasis and orchestrating inflammatory and regulatory immune processes. This review elucidates the immune interactions of macrophage galactose-type lectin (MGL, CD301) and Tn carbohydrate antigen. MGL is a C-type lectin receptor (CLR) primarily expressed by myeloid cells such as macrophages and immature dendritic cells. MGL recognizes terminal O-linked N-acetylgalactosamine (GalNAc) residue on the surface proteins, also known as Tn antigen (Tn). Tn is a truncated form of the elongated cell surface O-glycan. The hypoglycosylation leading to Tn may occur when the enzyme responsible for O-glycan elongation-T-synthase-or its associated chaperone-Cosmc-becomes functionally inhibited. As reviewed here, Tn expression is observed in many different neoplastic and non-neoplastic diseases, and the recognition of Tn by MGL plays an important role in regulating effector T cells, immune suppression, and the recognition of pathogens.
蛋白质-碳水化合物相互作用对于维持免疫稳态以及调控炎症和调节性免疫过程至关重要。本综述阐明了巨噬细胞半乳糖凝集素（MGL，CD301）和 Tn 碳水化合物抗原的免疫相互作用。MGL 是一种 C 型凝集素受体（CLR），主要表达于髓样细胞，如巨噬细胞和未成熟树突状细胞。MGL 识别表面蛋白上的末端 O-连接 N-乙酰半乳糖胺（GalNAc）残基，也称为 Tn 抗原（Tn）。Tn 是细胞表面 O-聚糖延长形式的截断形式。当负责 O-聚糖延长的酶-T-合成酶或其相关伴侣-Cosmc-功能受到抑制时，导致 Tn 的低聚糖化可能会发生。正如本文所综述的，Tn 的表达在许多不同的肿瘤性和非肿瘤性疾病中都观察到，并且 MGL 对 Tn 的识别在调节效应 T 细胞、免疫抑制和病原体识别方面发挥着重要作用。
