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） M细胞的疫苗递送系统。虽然已有关于疫苗与实验室啮齿动物NALT相互作用的研究，但很少有关于人类NALT相互作用的报道。1)为了弄清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，我们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30min、60min和90min。透射电镜观察发现，许多流感病毒粘附在M细胞表面，在孵育30分钟后被带入M细胞的细胞质囊泡中，在孵育60分钟后被转运到包膜淋巴样细胞中。用特异性识别唾液蛋白NeuAc α 2,6 Gal链的SNA凝集素对M细胞进行染色，发现M细胞表面存在丰富的人流感病毒受体。我们的研究结果表明，人鼻咽扁桃体的M细胞是甲型流感病毒进入的主要通道，并且病毒可以通过M细胞有效地转移到包裹的巨噬细胞和淋巴样细胞中。流感病毒通过M细胞转运到淋巴样细胞可能促进抗原向免疫系统的传递，这些发现可能对那些具有有效感染呼吸道外细胞能力的流感病毒的全身传递具有重要意义。2)为了在电镜和荧光显微镜下明确不同大小、浓度和表面涂层的荧光微粒在切除腺样组织上皮中的摄取能力，将切除的腺样组织在含颗粒的培养基中孵育120 min。透射电镜显示给药颗粒被NALT M细胞吸收。0.2 μm的小颗粒吸收量大于0.5、1.0和2.0 μm的大颗粒。颗粒吸收量随浓度的增加而增加，颗粒浓度的影响显著。包被聚l -溶酶和壳聚糖的0.5 μm颗粒比未包被的颗粒对人体NALT的吸收更大。综上所述，经鼻给药包被阳离子材料的更小的微颗粒可能是一种有效的经鼻预防呼吸道和肠道感染的方法。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