Zhang Aiguo, Lai Hanzhang, Xu Jiahua, Huang Wenke, Liu Yufu, Zhao Dawei, Chen Ruiai
College of Veterinary Medicine, South China Agricultural University, Tianhe District, Guangzhou, Guangdong Province, China.
Guangdong Enterprise Key Laboratory of Biotechnology R&D of Veterinary Biologics, Guangdong, Zhaoqing, Guangdong Province, China.
PLoS One. 2017 Jan 30;12(1):e0170681. doi: 10.1371/journal.pone.0170681. eCollection 2017.
Current commercial H9 avian influenza vaccines cannot provide satisfactory protective immunity against antigenic variant influenza viruses in ducks. Poly I:C, when used as an adjuvant, improves humoral and cellular immunity in many animals but has not been tested in ducks. In this study, we investigated the protective efficacy of Poly I:C as an adjuvant for an inactivated H9N2 Avian influenza vaccine in ducks. We found that an H9N2 vaccine administered with poly I:C (H9-PIC vaccine) induced a significantly more rapid response with higher anti-influenza antibody titers than those of the vaccine alone (H9 vaccine). Moreover, virus shedding was reduced in ducks immunized with the H9-PIC vaccine after challenge with an H9 subtype antigenic variant viruses. IFN-α, IFN-γ, IL-6 and MHC-II mRNA levels were all elevated in ducks receiving the H9-PIC vaccine. In addition, lower expression level of MHC-I may be a reason for inefficient protective ability against heterologous influenza viruses in H9-PIC vaccination of ducks. In conclusion, poly I:C adjuvant enhanced both humoral and cellular immune responses in ducks induced by immunization of inactivated H9N2 vaccine.
目前的商业化H9禽流感疫苗无法对鸭体内的抗原变异流感病毒提供令人满意的保护性免疫。聚肌胞苷酸（Poly I:C）用作佐剂时，可增强许多动物的体液免疫和细胞免疫，但尚未在鸭身上进行过测试。在本研究中，我们调查了Poly I:C作为灭活H9N2禽流感疫苗佐剂在鸭体内的保护效果。我们发现，与单独使用疫苗（H9疫苗）相比，添加Poly I:C的H9N2疫苗（H9-PIC疫苗）诱导产生的抗流感抗体滴度更高，反应速度明显更快。此外，用H9亚型抗原变异病毒攻击后，接种H9-PIC疫苗的鸭体内病毒排出量减少。接受H9-PIC疫苗的鸭体内IFN-α、IFN-γ、IL-6和MHC-II mRNA水平均升高。此外，MHC-I表达水平较低可能是鸭接种H9-PIC疫苗后对异源流感病毒保护能力不佳的原因之一。总之，Poly I:C佐剂增强了灭活H9N2疫苗免疫诱导的鸭体液免疫和细胞免疫反应。
