淋巴囊肿病毒27.8ku受体蛋白在牙鲆组织中的分布

Distribution of lymphocystis disease virus receptor-27.8 ku in flounder(Paralichthys olivaceus)

应用抗牙鲆淋巴囊肿病毒(lymphocystis disease virus,LCDV)受体蛋白(27.8 ku)的单克隆抗体(2G11和3D9)定位LCDV受体蛋白在牙鲆组织中的分布。通过对牙鲆外周血、白细胞、鳃、胃、肠、表皮、肝脏、头肾、体肾、脾、性腺、脑、心脏等进行LCDV受体蛋白的间接免疫荧光与免疫组织化学定位观察,发现在牙鲆外周血白细胞的细胞膜、鳃上皮细胞、表皮、胃黏膜上皮细胞顶端、肠上皮细胞、肝细胞、脾表层结缔组织细胞及头肾后端的肾小管上皮细胞内均有较强的阳性信号,表明这些部位分布有LCDV的27.8 ku受体蛋白,但在体肾、性腺、脑、心脏及外周血红细胞中未观察到阳性信号。推测LCDV通过与鳃、表皮及消化道上皮的受体结合进入牙鲆体内,通过与外周血白细胞上的受体结合侵染白细胞而进入血液循环,进而感染肝脏、脾脏、头肾等器官。

Lymphocystis disease virus（LCDV）is the causative agent of lymphocystis disease,which has infected more than 140 species of marine and freshwater fish belonging to 42 families worldwide and caused great economic losses.Determination of the receptor molecules on the surface of susceptible cells will contribute to the understanding of viral infection,pathogenesis and tissue tropism in hosts,which will also benefit the development of anti-viral therapeutic agents.In this paper,monoclonal antibodies（Mabs）2G11 and 3D9 against 27.8 ku receptor protein of LCDV were applied to detect LCDV receptor in the peripheral blood,leukocyte,gill,stomach,intestine,skin,liver,head-kidney,body kidney,spleen,gonad,brain and heart tissues in flounder（Paralichthys olivaceus）by indirect immunofluorescence assay and immunohistochemical experiment.Results showed that receptor-positive signals were found in cell membranes of leukocytes,gill,gastric mucosal cells,intestinal epidermal cells,epidermis,liver,connective tissue cells in the spleen surface and tubular epithelium behind the head-kidney,which indicated that LCDV 27.8 ku receptor protein existed in these tissues.No receptor-positive signals were observed in the body kidney,gonad,brain,heart tissues and red blood cells of P.olivaceus.We deduced that LCDV entered the fish＇s body through binding to the receptor molecules in gill,epidermis and gastrointestinal epithelium,or entered the peripheral blood and infected the leucocyte and then transmitted to other tissues（liver,spleen,head-kidney,etc.）through blood circulation.