Rabies lyssavirus (RABV) neutralizing IgG antibodies confer protection after rabies vaccination, although how the RABV-specific antibodies neutralize the virus is still unknown. As changes in the antibody‘s carbohydrate chain can interfere with its effector functions, we compared the glycosylation patterns of both neutralizing and non-neutralizing IgG1 induced by pre-exposure prophylaxis to human rabies and analyzed their influence on in vitro antibody neutralizing activities. Specific IgG1 were purified from human serum using affinity chromatography. Purity and avidity were analyzed by SDS-PAGE and indirect ELISA using NH₄SCN respectively. The N-linked oligosaccharide chain of the purified IgG antibody was evaluated using a lectin-based ELISA assay with a panel of seven lectins. The activity of purified IgG1 and neutralizing IgG1 deglycosylated by PNGase F enzyme were analyzed using the rapid fluorescent focus inhibition test. The purified IgG1 showed an electrophoretic pattern compatible with human IgG. All of the antibodies recognized RABV, although neutralizing IgG1 had a higher avidity (RAI = 80%) than non-neutralizing IgG1 (RAI = 30%). The neutralizing IgG1 also showed higher binding to WFA, ECA, WGA, and ConA lectins, indicating possible different N-acetylgalactosamine, galactose, N-acetylglucosamine, and mannose contents. Non-neutralizing IgG1, on the other hand, showed strong binding at UEA-1 and SNA, which bind to fucose and sialic acid residues respectively. Different glycosylation profiles were also observed in Fab and Fc fragments from neutralizing and non-neutralizing IgG1, although the deglycosylated IgG1 lost its neutralizing activity. Our results suggest that antibody glycosylation is important for neutralizing RABV in vitro, since neutralizing IgG1 has a different glycosylation profile than non-neutralizing IgG1. Further research will be needed to better evaluate the differential glycosylation patterns between IgG1 antibodies following vaccination.

狂犬病狂犬病病毒(RABV) 中和 IgG 抗体可在狂犬病疫苗接种后提供保护，尽管 RABV 特异性抗体如何中和病毒仍不清楚。由于抗体碳水化合物链的变化会干扰其效应器功能，我们比较了人类狂犬病暴露前预防诱导的中和和非中和 IgG1 的糖基化模式，并分析了它们对体外抗体中和活性的影响。使用亲和层析从人血清中纯化特异性 IgG1。纯度和亲合力分别通过 SDS-PAGE 和使用 NH ₄ SCN 的间接 ELISA 分析。N _使用基于凝集素的ELISA测定法对一组七种凝集素评估纯化的IgG抗体的连接寡糖链。使用快速荧光聚焦抑制试验分析纯化的 IgG1 和被 PNGase F 酶去糖基化的中和 IgG1 的活性。纯化的 IgG1 显示出与人 IgG 相容的电泳图谱。尽管中和性 IgG1 比非中和性 IgG1 (RAI = 30%) 具有更高的亲和力 (RAI = 80%)，但所有抗体都识别 RABV。中和 IgG1 还显示出与 WFA、ECA、WGA 和 ConA 凝集素的更高结合，表明可能存在不同的N-乙酰半乳糖胺、半乳糖、N-乙酰氨基葡萄糖和甘露糖含量。另一方面，非中和性 IgG1 在 UEA-1 和 SNA 处显示出强结合，它们分别与岩藻糖和唾液酸残基结合。在来自中和和非中和 IgG1 的 Fab 和 Fc 片段中也观察到不同的糖基化谱，尽管去糖基化的 IgG1 失去了中和活性。我们的结果表明，抗体糖基化对于体外中和 RABV 很重要，因为中和 IgG1 具有与非中和 IgG1 不同的糖基化特征。需要进一步的研究来更好地评估疫苗接种后 IgG1 抗体之间的差异糖基化模式。