牙鲆免疫相关组织特征及抗体阳性细胞的免疫组化定位

应用抗牙鲆免疫球蛋白单克隆抗体(2D8、1H1)对牙鲆外周血系统、肾、脾、肝、胰、肠道组织中抗体阳性细胞进行了定位观察，并对其组织学特征进行了描述。两株单抗均能在外周血滴片和组织切片中成功地检测到抗体阳性细胞。外周血系统中的抗体阳性细胞主要为淋巴细胞，没有发现抗体阳性的巨噬细胞；牙鲆头肾中没有肾单位，肾小管、肾小球等主要存在于后肾中，脾脏和肾脏都含有巨噬细胞、粒细胞、淋巴细胞等免疫相关细胞，抗体阳性细胞存在方式也极为相似，成簇或单独分布于黑色素巨噬细胞中心和血管周围；牙鲆的胰组织镶嵌在肝上，形成肝胰脏，也参与免疫应答，抗体阳性细胞单个存在，分布于肝组织中，胰组织中没有发现抗体阳性细胞；肠道抗体阳性细胞主要存在于固有层中，有成簇存在现象，在上皮层也可见到单个存在的抗体阳性细胞。

Studies on immunogiobulin-positive cells and immunologic tissues in Japanese flounder (Paralichthys olivaceus) using histological and immunohistochemical methods

Knowledge about the cells and organs involved in the fish immune system is important to improve fish immunoprophylaxis. Teleosts lack bone marrow and lymph nodes and the major lymphoid organs are thymus, kidney, spleen and gut-associated lymphoid tissue (GALT). In this paper, monoclonal antibodies (mabs, 2D8 and 1H1) raised against Japanese flounder (Paralichthys olivaceus) serum IgM were applied as probes. Histological, immunocytochemical and immunohistochemical detection of immunoglobulin-positive cells in the peripheral blood cells, kidney, liver-pancreas, spleen and gut associated lymphoid tissues of the Japanese flounder were successfully performed. Results showed that immunoglobulin-positive cells were found in all the sampled tissues. Immunoglobulin-positive cells with diffusely stained cytoplasmic were observed in the peripheral blood, but immunoglobulin-positive macrophages were not found. There were many macrophages, granulocytes, lymphocytes and other immune-related cells in spleen and kidney, immunoglobulin-positive cells were mostly present around the melanomacrophage centers (MMCs) and blood vessels in the spleen; the lymphoid immunoglobulin-positive cells in the kidney were also closely associated with the MMCs and existed in groups or dispersedly. The pancreas was surrounded with liver in flounder and formed liver-pancreas, immunoglobulin-positive cells were separately distributed in the hepatic tissue, but not in the pancreas tissue. Additionally, immunoglobulin-positive cells in the gut associated lymphoid tissue were rarely detected in the epithelial layer although many lymphocytes were observed, yet they were frequently present in the lamina propria in groups or separately, presumably as a part of the intestine involved in mucosal immune responses. The thymus of Japanese flounder degenerates with age and no thymus could be found about 12 months old in this study.