Laboratory of Vaccine Materials, Center for Vaccine and Adjuvant Research and Laboratory of Gut Environmental System, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Ibaraki, Osaka, 567-0085, Japan.
Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, 565-0871, Japan.
Sci Rep. 2018 Feb 13;8(1):2904. doi: 10.1038/s41598-018-21120-7.
Vaccine delivery is an essential element for the development of mucosal vaccine, but it remains to be investigated how physical barriers such as mucus and cilia affect vaccine delivery efficacy. Previously, we reported that C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) targeted claudin-4, which is expressed by the epithelium associated with nasopharynx-associated lymphoid tissue (NALT), and could be effective as a nasal vaccine delivery. Mice lacking tubulin tyrosine ligase-like family, member 1 (Ttll1-KO mice) showed mucus accumulation in nasal cavity due to the impaired motility of respiratory cilia. Ttll1-KO mice nasally immunized with C-CPE fused to pneumococcal surface protein A (PspA-C-CPE) showed reduced PspA-specific nasal IgA responses, impaired germinal center formation, and decreased germinal center B-cells and follicular helper T cells in the NALT. Although there was no change in the expression of claudin-4 in the NALT epithelium in Ttll1-KO mice, the epithelium was covered by a dense mucus that prevented the binding of PspA-C-CPE to NALT. However, administration of expectorant N-acetylcysteine removed the mucus and rescued the PspA-specific nasal IgA response. These results show that the accumulation of mucus caused by impaired respiratory cilia function is an interfering factor in the C-CPE-based claudin-4-targeting nasal vaccine.
疫苗传递是黏膜疫苗发展的一个重要因素，但物理屏障（如黏液和纤毛）如何影响疫苗传递效率仍有待研究。此前，我们报道了产气荚膜梭菌肠毒素 C 端片段（C-CPE）靶向 Claudin-4，Claudin-4 由与鼻咽相关淋巴组织（NALT）相关的上皮细胞表达，可作为鼻用疫苗传递的有效载体。微管酪氨酸连接酶样家族成员 1（Ttll1-KO）缺失的小鼠由于呼吸纤毛运动受损而导致鼻腔内黏液积聚。用与肺炎球菌表面蛋白 A（PspA-C-CPE）融合的 C-CPE 对 Ttll1-KO 小鼠进行鼻腔免疫接种，会导致 PspA 特异性鼻腔 IgA 反应减少、生发中心形成受损以及 NALT 中的生发中心 B 细胞和滤泡辅助 T 细胞减少。尽管 Ttll1-KO 小鼠的 NALT 上皮细胞中 Claudin-4 的表达没有变化，但上皮细胞被致密的黏液覆盖，阻止了 PspA-C-CPE 与 NALT 的结合。然而，给予化痰剂 N-乙酰半胱氨酸可去除黏液并恢复 PspA 特异性鼻腔 IgA 反应。这些结果表明，呼吸纤毛功能受损引起的黏液积聚是 C-CPE 靶向 Claudin-4 的鼻用疫苗的干扰因素。
