Zhu Shanshan, Zhang Chunyan, Wang Jing, Wei Li, Quan Rong, Yang Jiayu, Yan Xu, Li Zixuan, She Ruiping, Hu Fengjiao, Liu Jue
Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, No. 9 Shuguang Garden Middle Road, Haidian District, Beijing, 100097, People's Republic of China.
College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100197, People's Republic of China.
PLoS One. 2016 Feb 5;11(2):e0147432. doi: 10.1371/journal.pone.0147432. eCollection 2016.
In a recent study, we reported that a recombinant protein from fusion expression of flagellin to porcine circovirus type 2 (PCV2) Cap induced robust humoral and cell-mediated immunity that afforded full protection for PCV2 infection using BALB/c mice. Here, we further evaluated the immunogenicity and protection of the recombinant protein using specific pathogen free (SPF) pigs. Twenty-five 3-week-old piglets without passively acquired immunity were divided into 5 groups. All piglets except negative controls were challenged with a virulent PCV2 at 21 days after booster vaccination and necropsied at 21 days post-challenge. Vaccination of piglets with the recombinant protein without adjuvant induced strong humoral and cellular immune responses as observed by high levels of PCV2-specific IgG antibodies and neutralizing antibodies, as well as frequencies of PCV2-specific IFN-γ-secreting cells that conferred good protection against PCV2 challenge, with significant reduced PCV2 viremia, mild lesions, low PCV2 antigen-positive cells, as well as improved body weight gain, comparable to piglets vaccinated with a commercial PCV2 subunit vaccine. These results further demonstrated that the recombinant flagellin-Cap fusion protein is capable of inducing solid protective humoral and cellular immunity when administered to pigs, thereby becoming an effective PCV2 vaccine candidate for control of PCV2 infection.
在最近的一项研究中，我们报道了一种由鞭毛蛋白与猪圆环病毒2型（PCV2）Cap融合表达产生的重组蛋白，该重组蛋白在BALB/c小鼠中诱导了强大的体液免疫和细胞介导免疫，对PCV2感染提供了完全保护。在此，我们使用无特定病原体（SPF）猪进一步评估了该重组蛋白的免疫原性和保护作用。将25只3周龄无被动获得性免疫的仔猪分为5组。除阴性对照组外，所有仔猪在加强免疫后21天用强毒PCV2进行攻毒，并在攻毒后21天进行剖检。用无佐剂的重组蛋白对仔猪进行疫苗接种，可诱导强烈的体液免疫和细胞免疫反应，表现为高水平的PCV2特异性IgG抗体和中和抗体，以及PCV2特异性分泌IFN-γ细胞的频率，这些反应对PCV2攻毒提供了良好的保护，PCV2病毒血症显著降低，病变轻微，PCV2抗原阳性细胞数量减少，体重增加改善，与接种商业PCV2亚单位疫苗的仔猪相当。这些结果进一步证明，重组鞭毛蛋白-Cap融合蛋白在给猪接种时能够诱导强大的保护性体液免疫和细胞免疫，从而成为控制PCV2感染的一种有效的PCV2疫苗候选物。
