Laboratory of Microbiology and Immunology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-Ku, Chiba, 260-8675, Japan.
Sci Rep. 2023 Sep 21;13(1):15740. doi: 10.1038/s41598-023-43017-w.
Lymphocyte homing is mediated by the interaction between L-selectin on lymphocytes and its glycoprotein ligands modified with 6-sulfo sialyl Lewis x (6-sulfo sLe) glycans on high endothelial venules (HEVs) in peripheral lymph nodes (PLNs). However, the lack of specific antibodies reactive with both human and mouse 6-sulfo sLe has limited our understanding of its function in vivo. Here, we generated a novel monoclonal antibody, termed SF1, that specifically reacts with 6-sulfo sLe expressed on HEVs in both species in a manner dependent on sulfate, fucose, and sialic acid modifications. Glycan array and biolayer interferometry analyses indicated that SF1 specifically bound to 6-sulfo sLe with a dissociation constant of 6.09 × 10 M. SF1 specifically bound to four glycoproteins from PLNs corresponding to the molecular sizes of L-selectin ligand glycoproteins. Consistently, SF1 inhibited L-selectin-dependent lymphocyte rolling on 6-sulfo sLe-expressing cells ex vivo and lymphocyte homing to PLNs and nasal-associated lymphoid tissues in vivo. Furthermore, SF1 significantly attenuated ovalbumin-induced allergic rhinitis in mice in association with significant suppression of Th2 immune responses. Collectively, these results suggest that SF1 can be useful for the functional analysis of 6-sulfo sLe and may potentially serve as a novel therapeutic agent against immune-related diseases.
淋巴细胞归巢是由淋巴细胞上的 L-选择素与其在周围淋巴结（PLN）中的高内皮小静脉（HEV）上的 6-硫酸唾液酸 Lewis x（6-sulfo sLe）糖蛋白配体相互作用介导的。然而，缺乏与人和小鼠 6-硫酸 sLe 均反应的特异性抗体限制了我们对其体内功能的理解。在这里，我们生成了一种新型单克隆抗体，称为 SF1，它以依赖于硫酸盐、岩藻糖和唾液酸修饰的方式特异性地与两种物种的 HEV 上表达的 6-硫酸 sLe 反应。糖基阵列和生物层干涉分析表明，SF1 特异性地以 6.09×10 M 的解离常数结合 6-硫酸 sLe。SF1 特异性地与来自 PLN 的四种糖蛋白结合，对应于 L-选择素配体糖蛋白的分子量。一致地，SF1 特异性地抑制了体外表达 6-硫酸 sLe 的细胞上 L-选择素依赖性淋巴细胞滚动以及体内淋巴细胞归巢到 PLN 和鼻相关淋巴组织。此外，SF1 显著减轻了小鼠的卵清蛋白诱导的变应性鼻炎，同时显著抑制了 Th2 免疫反应。总之，这些结果表明 SF1 可用于 6-硫酸 sLe 的功能分析，并且可能潜在地用作针对免疫相关疾病的新型治疗剂。
