Xiao Yongle, Zhang Huan, Chen Jianlin, Chen Yi, Li Jinghai, Song Tingyu, Zeng Guangzhi, Chen Xiaohui, Lü Xuebin, Fang Pengfei, Gao Rong
College of Life Sciences, Sichuan University, Chengdu 610065, China.
School of Basic Medical Sciences, North Sichuan Medical College, Nanchong 637000, China.
Vaccines (Basel). 2020 May 26;8(2):250. doi: 10.3390/vaccines8020250.
Vaccines against Porcine circovirus type 2 (PCV2) have been studied intensely and found to be effective in decreasing mortality and improving growth in swine populations. In this study, interleukin-23 (IL-23) gene was cloned from peripheral blood mononuclear cells (PBMCs) of Tibetan pigs and inserted into a eukaryotic VR1020 expression vector-VRIL23. Coated with chitosan (CS), the VRIL23-CS was intramuscularly injected into 3-week-old piglets with PCV2 vaccine. The blood was collected after vaccination at 0, 1, 2, 4, 8, and 12 weeks, respectively, to detect the immunological changes. The IgG2a and specific PCV2 antibodies were detected using ELISA, and blood CD4+ and CD8+ T cells were quantified by flow cytometry. Quantitative fluorescence PCR was used to evaluate the expression of immune genes. The results indicate that leukocytes, erythrocytes, and CD4+ and CD8+ T cells increased significantly in the blood of VRIL23-CS inoculated piglets in comparison with the control ( < 0.05 and so did the IgG2a and PCV2 antibodies. In addition, the expressions of Toll-like receptor (TLR) 2, TLR7, cluster of differentiation (CD) 45, IL-15, IL-12, signal transducer and activator of transcription (STAT1, STAT2, STAT3, STAT4, and B-cell lymphoma (Bcl)-2 genes were also obviously higher in the VRIL23-CS inoculated pigs at different time points ( < 0.05. Overall, the results demonstrated that VRIL23-CS can enhance the comprehensive immune responses to PCV2 vaccine in vivo and has the promising potential to be developed into a safe and effective adjuvant to promote the immunity of pig against PCV disease.
针对猪圆环病毒2型（PCV2）的疫苗已得到深入研究，并发现其在降低猪群死亡率和促进生长方面有效。在本研究中，从藏猪外周血单个核细胞（PBMCs）中克隆白细胞介素-23（IL-23）基因，并将其插入真核VR1020表达载体-VRIL23中。用壳聚糖（CS）包被后，将VRIL23-CS肌肉注射到接种PCV2疫苗的3周龄仔猪体内。分别在接种疫苗后的0、1、2、4、8和12周采集血液，以检测免疫变化。使用ELISA检测IgG2a和特异性PCV2抗体，通过流式细胞术对血液中的CD4+和CD8+ T细胞进行定量。采用定量荧光PCR评估免疫基因的表达。结果表明，与对照组相比，接种VRIL23-CS的仔猪血液中的白细胞、红细胞以及CD4+和CD8+ T细胞显著增加（<0.05），IgG2a和PCV2抗体也增加。此外，在不同时间点，接种VRIL23-CS的猪中Toll样受体（TLR）2、TLR7、分化簇（CD）45、IL-15、IL-12、信号转导和转录激活因子（STAT1、STAT2、STAT3、STAT4）以及B细胞淋巴瘤（Bcl）-2基因的表达也明显更高（<0.05）。总体而言，结果表明VRIL23-CS可增强体内对PCV2疫苗的综合免疫反应，具有开发成为安全有效的佐剂以促进猪对PCV疾病免疫的潜在前景。
