The development of a vaccine delivery system through M-cells

在考虑疫苗策略时，重要的是研究通过人鼻咽淋巴组织（NALT）的M细胞的疫苗递送系统。虽然已经有关于疫苗和NALT在实验室啮齿动物中的相互作用的研究，但关于人NALT中的相互作用的报道很少。1）为了阐明M细胞是否可以作为流感病毒进入人鼻咽淋巴组织的通道，将切除的腺样组织分别在含有甲型流感病毒的培养基中孵育30、60和90分钟。透射电镜观察显示，许多流感病毒粘附在M细胞表面，孵育30 min后被吸收到M细胞的胞质囊泡中，孵育60 min后病毒被转运到包裹的淋巴样细胞中。通过用特异性识别唾液酸蛋白NeuAc α 2，6 Gal连接的接骨木凝集素（SNA）染色M细胞，也发现了M细胞中NeuAc α 2，6 Gal的表达。 ...更多信息 发现人流感病毒的大量受体存在于M细胞表面。我们的研究结果表明，人鼻咽扁桃体的M细胞作为一个主要的端口，流感病毒进入，并可以有效地转移到M细胞的包裹的巨噬细胞和淋巴细胞。M细胞将流感病毒转运至淋巴样细胞可能促进抗原递送至免疫系统，这些发现可能对于那些具有生产性感染呼吸道外细胞能力的流感病毒的全身递送很重要。2）为了通过电子显微镜和荧光显微镜阐明几种尺寸、浓度和表面涂层的荧光微粒在切除的腺样体组织的上皮中的摄取能力，将切除的腺样体组织在含有微粒的培养基中孵育120分钟。透射电子显微镜显示，所施用的微粒被NALT M细胞吸收。0.2 μm的最小颗粒显示出比0.5、1.0和2.0 μm的较大颗粒更大的摄取。随着浓度的增加，颗粒摄取增加，颗粒浓度的显著影响证明了这一点。用聚L-赖氨酸和壳聚糖包被的0.5 μm颗粒在人NALT中显示出比未包被的颗粒更大的摄取。总之，鼻腔施用涂覆有阳离子材料的较小微粒可能是经鼻接种针对人类呼吸道和肠道感染的有用方法。少

In considering vaccine strategies, it is important to investigate vaccine delivery systems through the M cells of human nasopharyngeal lymphoid tissue (NALT). Although there have been investigations regarding the interaction between vaccines and NALT in laboratory rodents, there have been few report on interaction in human NALT. 1)To clarify whether M cells could function as a gateway for influenza virus into human nasopharyngeal lymphoid tissue, excised adenoid tissue was incubated in the media containing influenza A virus for 30, 60, and 90 min, respectively. Transmission electron microscopic observation revealed that many influenza viruses adhered to M cell surfaces and were taken up into the cytoplasmic vesicles of M cells after 30 min incubation, and that the viruses had been transported into enfolded lymphoid cells after 60 min incubation. By staining M cells with Sambucus nigra (SNA) lectin, which specifically recognizes the NeuAc α 2,6 Gal linkage of sialoprotein, it was also f … More ound that abundant receptors for the human influenza virus are present on the M cell surface. Our findings indicated that M cells of human nasopharyngeal tonsils function as a major port for influenza A virus entry, and that the virus could be efficiently transferred to enfolded macrophages and lymphoid cells by M cells. The transport of influenza viruses to lymphoid cells by M cells may promote antigen delivery to the immune system, and these findings may be important for systemic delivery of those influenza viruses that have the capacity to productively infect cells outside of the respiratory tract. 2)To clarify the uptake capacity of fluorescent microparticles of several sizes, concentrations and surface coatings in the epithelium of removed adenoid tissue by electron microscopy and fluorescent microscopy, the excised adenoid tissue was incubated for 120 min in media containing particles. Transmission electron microscopy showed that the administered microparticles were taken up by NALT M cells. The smallest particles of 0.2 μm showed greater uptake than larger ones of 0.5, 1.0 and 2.0 μm. The particle uptake was increased as the concentrarion increased, as evidenced by a significant effect of particle concentration. The 0.5 μm particles, which were coated with poly L-lysin and chitosan, showed greater uptake in human NALT than uncoated particles. In conclusion, nasal administration of smaller microparticles coated with cationic materials might be a useful method of transnasal vaccination against respiratory and intestinal infections in humans. Less