Development of model system to analyze the antigen epitope to induce cell-mediated immunity in fish

FISH具有特异的抗原识别分子和B、T淋巴细胞，可激发针对多种抗原的特异性免疫反应。然而，在鱼类中，由于缺乏体内和体外模型系统，与体液免疫相比，关于细胞免疫的信息有限。尽管病毒性疾病是水产养殖中的严重问题，但针对病毒疾病的疫苗在鱼类中的应用有限。这种疫苗的开发需要识别和表征可诱导保护性免疫的病毒抗原。众所周知，细胞介导的杀伤是控制病毒疾病的最重要的防御机制。该研究项目的目标是开发实验模型系统，以分析细胞免疫中涉及的保护性抗原或表位，以开发鱼类疫苗。与东京水产大学的冈本博士和日本水产养殖研究所的…博士合作此外，我们还建立了几种用于特异性细胞免疫的检测系统，特别是利用克隆性人参和同基因细胞系对细胞毒T细胞功能的检测。这些包括移植物抗宿主反应(GVHR)和细胞介导的对异基因红细胞或细胞系的细胞毒性(CMC)。在本研究项目中，我们进一步进行了研究，建立了CMC对抗病毒感染细胞的模型体系，并结合鱼类病毒分析了同源人参和细胞系的保护机制。我们还广泛分析了虹鱼MHC基因的多态性，发现鲑鱼细胞系(RTG-2)与纯合子克隆性虹鱼(C25克隆)具有相同的MHC I类等位基因。我们用IHNV-G DNA免疫致敏的C25克隆鲑鱼淋巴细胞或以IHNV和RTG-2细胞感染为靶细胞，证明了MHC限制性细胞介导的细胞毒作用。本研究建立的实验模型系统可用于研究细胞免疫中的保护性抗原或表位，用于鱼类疫苗的研制，并可用于研究特异性细胞免疫的识别和杀伤机制。较少

Fish possess specific antigen recognition molecules as well as B and T lymphocytes and can evoke specific immune responses against a variety of antigens. In fish, however, information on cell-mediated immunity is limited when compared to those on humoral immunity due to the lack of in vivo and in vitro model systems. Vaccine against viral disease is limited in fish despite that viral diseases are serious problem in aquaculture. Development of such vaccines requires identification and characterization of viral antigens which induce protective immunity. It is well known that cell-mediated killing is most important defense mechanisms in the control of viral disease. The objective of this research project is to develop experimental model systems to analyze the protective antigens or epitopes involved in cell-mediated immunity for the development of fish vaccines.In collaboration with Dr. Okamoto at Tokyo University of Fisheries and Dr. Ototake at National Research Institute of Aquaculture … More we have established several assay systems for specific cell-mediated immunity, particularly on cytotoxic T-cell function employing clonal ginbuna and a syngeneic cell line. Those include the graft-versus host reaction (GVHR) and cell-mediated cytotoxicity (CMC) against allogeneic erythrocytes or cell lines. In the present research project we further pursued the studies and have established model systems for CMC against virus-infected cells and analyzed the protection mechanism using isogeneic ginbuna and cell lines together with fish viruses. We also extensively analyzed the MHC polymorphism in rainbow trout and found that trout cell line (RTG-2) shares the same MHC class I allele with homozygous clonal rainbow trout (C25 clone). We demonstrated MHC-restricted cell-mediated cytotoxicity against virus-infected cell lines using lymphocytes from C25 clonal trout sensitized by DNA immunization with IHNV-G or by infection with IHNV and RTG-2 cells as target. Experimental model systems established in the present study can be applied to investigate the protective antigens or epitopes involved in cell-mediated immunity for the development of fish vaccines as well as to investigate the recognition and killing g mechanism of specific cell-mediated immunity. Less