Zeng Chuili, Tang Xiaoqian, Du Yang, Sheng Xiuzhen, Xing Jing, Zhan Wenbin
Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, 5 Yushan Road, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
Vet Immunol Immunopathol. 2018 May;199:53-60. doi: 10.1016/j.vetimm.2018.03.007. Epub 2018 Mar 23.
Intramuscular (i.m.) injection is one of the common delivery methods of vaccination in aquaculture, which could induce an ideal immune protection to fish. In the present study, the olive flounders (Paralichthys olivaceus) were injected intramuscularly with 200 μl of three concentrations of formalin-inactivated Edwardsiella tarda bacterin (10, 10, 10 CFU ml) to investigate the transportation and dynamic distribution of antigen uptake in tissues by absolute real-time quantitative PCR (qPCR). The amount of uptaken antigen increased firstly, and then decreased. The peak occurred first in the blood at 6-9 h after i.m. injection, and in the spleen and head kidney at 9-15 h, then in the liver, gill and muscle at 15-24 h, finally in the skin and intestine at 36 h. The amount of uptaken antigen was highest in the head kidney, followed by in the spleen, blood, gill, and liver, and lowest in the muscle, skin and intestine. Among the three dose groups, the amount of uptaken antigen in all tested tissues became higher with the increasing dose of injected bacterin. Moreover, the tissue distribution of antigen uptake was investigated by indirect immunofluorescence assay (IIFA) at 15 h after i.m. injection with 200 μl of 10 CFU mlE. tarda bacterin. The distribution of antigen was mainly observed in the head kidney, then in the spleen, blood, liver, gill and muscle, and least in the skin and intestine, which correlated with the results of absolute qPCR detection. Furthermore, the expression levels of MHC Iα, MHC IIα, CD4-1 and CD8α were detected by RT-qPCR. The expression of these four genes peaked highest in the head kidney, followed by in the spleen, liver, blood and gill, and lowest in the muscle, skin and intestine, and the levels increased in parallel with the increasing dose of injected vaccine. All these results provided an important insight into the dynamic transportation of antigen uptake, and also deepened the understanding of immune response to the i.m. injection.
肌肉注射是水产养殖中常见的疫苗接种方式之一，可诱导鱼类产生理想的免疫保护。在本研究中，给牙鲆（Paralichthys olivaceus）肌肉注射200 μl三种浓度（10⁷、10⁸、10⁹ CFU/ml）的福尔马林灭活迟缓爱德华氏菌菌苗，通过绝对实时定量PCR（qPCR）研究抗原摄取在组织中的转运和动态分布。摄取的抗原量先增加后减少。肌肉注射后，峰值首先出现在血液中，时间为6 - 9小时，然后在脾脏和头肾中，时间为9 - 15小时，接着在肝脏、鳃和肌肉中，时间为15 - 24小时，最后在皮肤和肠道中，时间为36小时。摄取的抗原量在头肾中最高，其次是脾脏、血液、鳃和肝脏，在肌肉、皮肤和肠道中最低。在三个剂量组中，所有测试组织中摄取的抗原量随着注射菌苗剂量的增加而升高。此外，在肌肉注射200 μl 10⁸ CFU/ml迟缓爱德华氏菌菌苗后15小时，通过间接免疫荧光分析（IIFA）研究抗原摄取的组织分布。抗原分布主要在头肾中观察到，其次是脾脏、血液、肝脏、鳃和肌肉，在皮肤和肠道中最少，这与绝对qPCR检测结果相关。此外，通过RT - qPCR检测MHC Iα、MHC IIα、CD4 - 1和CD8α的表达水平。这四个基因的表达在头肾中达到最高峰值，其次是脾脏、肝脏、血液和鳃，在肌肉、皮肤和肠道中最低，并且表达水平随着注射疫苗剂量的增加而平行升高。所有这些结果为抗原摄取的动态转运提供了重要见解，也加深了对肌肉注射免疫反应的理解。
