疫苗添加剂：聚乙烯亚胺能加强免疫应答
一个国际团队的最新研究结果显示，在针对流感等疾病的疫苗中添加一种名为聚乙烯亚胺的物质，可增强疫苗效果，实验鼠如果注射了这种疫苗后，身体可有效对抗大剂量的流感病毒。
机体免疫系统对抗原刺激所产生的以排除抗原为目的的生理过程。这个过程是免疫系统各部分生理功能的综合体现，包括了抗原递呈、淋巴细胞活化、免疫分子形成及免疫效应发生等一系列的生理反应。通过有效的免疫应答，机体得以维护内环境的稳定。
疫苗起作用的原理是“训练”免疫系统抗击入侵的病毒和细菌，有些添加剂能增强这种应答，因此许多疫苗都含有被称为“辅助剂”的药品添加剂。英国牛津大学等机构的研究人员在新一期《自然—生物技术》（Nature Biotechnology）杂志上发表报告说，聚乙烯亚胺这种添加剂可增强多种疫苗的效果，包括流感疫苗、疱疹疫苗和艾滋病疫苗等。
实验显示，老鼠只需注射一次含有这种添加剂的流感疫苗，接下来即使接触通常情况下会致死的大剂量流感病毒，体内免疫系统仍能有效对抗，效果好于没有添加剂的疫苗，以及使用其他添加剂的疫苗。
研究人员说，接下来将在雪貂身上进行相关实验，雪貂的呼吸系统与老鼠相比更接近人类。
据介绍，聚乙烯亚胺作为疫苗添加剂的另一个优点是可以通过黏膜组织起作用，能够加入那些采用鼻腔吸入方式的疫苗中，使用这些疫苗无需打针，只要深吸一口气即可。由于流感等疾病的病毒也是通过呼吸系统黏膜入侵人体，使用这样的疫苗防治流感也许更有效。
Polyethyleneimine is a potent mucosal adjuvant for viral glycoprotein antigens
Frank Wegmann, Kate H Gartlan, Ali M Harandi, Sarah A Brinckmann, Margherita Coccia, William R Hillson, Wai Ling Kok, Suzanne Cole, Ling-Pei Ho, Teresa Lambe, Manoj Puthia, Catharina Svanborg, Erin M Scherer, George Krashias, Adam Williams, Joseph N Blattman, Philip D Greenberg, Richard A Flavell, Amin E Moghaddam, Neil C Sheppard & Quentin J Sattentau
Protection against mucosally transmitted infections probably requires immunity at the site of pathogen entry1, yet there are no mucosal adjuvant formulations licensed for human use. Polyethyleneimine (PEI) represents a family of organic polycations used as nucleic acid transfection reagents in vitro and DNA vaccine delivery vehicles in vivo2, 3. Here we show that diverse PEI forms have potent mucosal adjuvant activity for viral subunit glycoprotein antigens. A single intranasal administration of influenza hemagglutinin or herpes simplex virus type-2 (HSV-2) glycoprotein D with PEI elicited robust antibody-mediated protection from an otherwise lethal infection, and was superior to existing experimental mucosal adjuvants. PEI formed nanoscale complexes with antigen, which were taken up by antigen-presenting cells in vitro and in vivo, promoted dendritic cell trafficking to draining lymph nodes and induced non-proinflammatory cytokine responses. PEI adjuvanticity required release of host double-stranded DNA that triggered Irf3-dependent signaling. PEI therefore merits further investigation as a mucosal adjuvant for human use.
文献链接：Polyethyleneimine is a potent mucosal adjuvant for viral glycoprotein antigens
