Beta-1,4-半乳糖基转移酶-3 (B4GALT3) 属于 β-1,4-半乳糖基转移酶 (B4GALT) 家族，负责将 UDP-半乳糖转移至末端 N-乙酰葡糖胺。 B4GALT3 在肿瘤和邻近正常组织中差异表达，并且与神经母细胞瘤、宫颈癌和膀胱癌等多种癌症的临床预后相关。然而，B4GALT3 在肿瘤免疫微环境 (TIME) 中的确切作用仍不清楚。在这里，我们的目的是阐明 B4GALT3 在 TIME 中的功能。为了研究 B4GALT3 在癌症免疫中的功能，将弱或强免疫原性肿瘤细胞皮下移植到野生型 (WT) 和 B4galt3 敲除 (KO) 小鼠中。进行骨髓移植和 CD8 T 细胞耗竭实验，以阐明免疫细胞在抑制 B4galt3 KO 小鼠肿瘤生长中的作用。使用流式细胞术和 RNA 测序分析肿瘤区域和浸润 CD8 T 细胞的细胞类型和基因表达。使用基于液相色谱串联质谱 (LC-MS/MS) 的糖蛋白组学方法比较 WT 和 B4galt3 KO 小鼠的 N-糖基化蛋白。B4galt3 KO 小鼠表现出强免疫原性肿瘤的生长受到抑制，CD8 T 细胞浸润显着增加肿瘤内。值得注意的是，B4galt3 缺陷导致多种蛋白质 N-聚糖修饰发生变化，包括参与 T 细胞活性和增殖的整合素 α L (ITGAL)。体外实验表明，B4galt3 KO CD8 T 细胞更容易被激活，并且与 ITGAL 相关的 FAK 下游磷酸化增加。我们的研究表明，B4galt3 缺陷可以潜在地增强抗肿瘤免疫反应，主要是通过增强 CD8 T 细胞的流入。 B4GALT3 可能通过在 CD8 T 细胞表面合成分子的聚糖结构来抑制癌症免疫，免疫细胞中 ITGAL 聚糖结构的变化证明了这一点。重要的是，B4galt3 KO 小鼠没有表现出对生长、发育或繁殖的不利影响，这强调了 B4GALT3 作为癌症治疗的有前景且安全的治疗靶点的潜力。版权所有 © 2023 Wei, Naruse, Takakura, Sugihara, Pan, Ikeda, Kawasaki and浅野。

Beta-1,4-galactosyltransferase-3 (B4GALT3) belongs to the family of beta-1,4-galactosyltransferases (B4GALTs) and is responsible for the transfer of UDP-galactose to terminal N-acetylglucosamine. B4GALT3 is differentially expressed in tumors and adjacent normal tissues, and is correlated with clinical prognosis in several cancers, including neuroblastoma, cervical cancer, and bladder cancer. However, the exact role of B4GALT3 in the tumor immune microenvironment (TIME) remains unclear. Here, we aimed to elucidate the function of B4GALT3 in the TIME.To study the functions of B4GALT3 in cancer immunity, either weakly or strongly immunogenic tumor cells were subcutaneously transplanted into wild-type (WT) and B4galt3 knockout (KO) mice. Bone marrow transplantation and CD8+ T cell depletion experiments were conducted to elucidate the role of immune cells in suppressing tumor growth in B4galt3 KO mice. The cell types and gene expression in the tumor region and infiltrating CD8+ T cells were analyzed using flow cytometry and RNA sequencing. N-glycosylated proteins from WT and B4galt3 KO mice were compared using the liquid chromatography tandem mass spectrometry (LC-MS/MS)-based glycoproteomic approach.B4galt3 KO mice exhibited suppressed growth of strongly immunogenic tumors with a notable increase in CD8+ T cell infiltration within tumors. Notably, B4galt3 deficiency led to changes in N-glycan modification of several proteins, including integrin alpha L (ITGAL), involved in T cell activity and proliferation. In vitro experiments suggested that B4galt3 KO CD8+ T cells were more susceptible to activation and displayed increased downstream phosphorylation of FAK linked to ITGAL.Our study demonstrates that B4galt3 deficiency can potentially boost anti-tumor immune responses, largely through enhancing the influx of CD8+ T cells. B4GALT3 might be suppressing cancer immunity by synthesizing the glycan structure of molecules on the CD8+ T cell surface, as evidenced by the changes in the glycan structure of ITGAL in immune cells. Importantly, B4galt3 KO mice showed no adverse effects on growth, development, or reproduction, underscoring the potential of B4GALT3 as a promising and safe therapeutic target for cancer treatment.Copyright © 2023 Wei, Naruse, Takakura, Sugihara, Pan, Ikeda, Kawasaki and Asano.