Huang Huai-Ying, Silva Benji Brayan I, Tsai Shen-Pang, Tsai Ching-Yi, Tyan Yu-Chang, Lin Tzu-Che, Flores Ronilo Jose D, Chuang Kuo-Pin
International Degree Program in Animal Vaccine Technology, International College, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
Graduate School, University of the Philippines Los Baños, Laguna 4031, Philippines.
Vaccines (Basel). 2021 Jan 28;9(2):98. doi: 10.3390/vaccines9020098.
Pigeon circovirus (PiCV) is the most recurrent virus diagnosed in pigeons and is among the major causative agents of young pigeon disease syndrome (YPDS). Due to the lack of an established laboratory protocol for PiCV cultivation, development of prophylaxis is hampered. Alternatively, virus-like particles (VLPs), which closely resemble native viruses but lack the viral genetic material, can be generated using a wide range of expression systems and are shown to have strong immunogenicity. Therefore, the use of VLPs provides a promising prospect for vaccine development. In this study, transfected human embryonic kidney (HEK-293) cells, a mammalian expression system, were used to express the PiCV capsid protein (Cap), which is a major component of PiCV and believed to contain antibody epitopes, to obtain self-assembled VLPs. The VLPs were observed to have a spherical morphology with diameters ranging from 12 to 26 nm. Subcutaneous immunization of pigeons with 100 µg PiCV rCap-VLPs supplemented with water-in-oil-in-water (W/O/W) adjuvant induced specific antibodies against PiCV. Observations of the cytokine expression and T-cell proliferation levels in spleen samples showed significantly higher T-cell proliferation and IFN- γ expression in pigeons immunized with VLPs compared to the controls ( < 0.05). Experimentally infected pigeons that were vaccinated with VLPs also showed no detectable viral titer. The results of the current study demonstrated the potential use of PiCV rCap-VLPs as an effective vaccine candidate against PiCV.
鸽圆环病毒（PiCV）是在鸽子中诊断出的最常见病毒，也是幼鸽疾病综合征（YPDS）的主要病原体之一。由于缺乏用于PiCV培养的既定实验室方案，预防措施的开发受到阻碍。另外，病毒样颗粒（VLP）与天然病毒非常相似，但缺乏病毒遗传物质，可以使用多种表达系统产生，并且显示具有很强的免疫原性。因此，VLP的使用为疫苗开发提供了一个有前景的前景。在本研究中，转染的人胚肾（HEK-293）细胞，一种哺乳动物表达系统，被用于表达PiCV衣壳蛋白（Cap），它是PiCV的主要成分，并且被认为含有抗体表位，以获得自组装的VLP。观察到VLP具有球形形态，直径范围为12至26nm。用补充有水包油包水（W/O/W）佐剂的100μg PiCV rCap-VLP对鸽子进行皮下免疫诱导了针对PiCV的特异性抗体。对脾脏样品中细胞因子表达和T细胞增殖水平的观察表明，与对照组相比，用VLP免疫的鸽子中T细胞增殖和IFN-γ表达显著更高（<0.05）。用VLP接种疫苗的实验感染鸽子也未检测到病毒滴度。本研究结果证明了PiCV rCap-VLP作为抗PiCV有效疫苗候选物潜在用途。
