动物模型,EBV z-bo 2020-08-12 465

　　(1) The replication method mainly uses transgene and gene knockout technology to establish related animal models.

　　(2) Model features Latent membrane protein (LMP): including LMP-1, 2A, 28. LMP-1 gene is currently the only confirmed EB virus malignant transformation gene. EBV-related animal models There are not many EBV-related animal models established so far, and they mainly focus on the study of LMP-1. Wilson et al. used the immunoglobulin gene promoter Eμ specifically expressed in B lymphocytes to construct a BNLF-1 (LMP-1 gene) transgene. The resulting transgenic mice have epithelial proliferative lesions similar to oral mucosa autoplaque. And most of them died during the developmental period, and no experimental evidence that BNLF-1 gene causes tumors in transgenic animals has been obtained. The most important reason for its failure may be that it did not use a suitable promoter. Kulwichit et al. used immunoglobulin heavy chain promoters and enhancers to construct LMP-1 gene transgenic mice. B-cell lymphoma was induced in 42% of transgenic mice, and the incidence of B-cell lymphoma increased with age. There is only high expression of LMP-1 in transgenic mice, indicating that LMP-1 oncoprotein plays a key role in the occurrence and development of EBV-related lymphoma. The most important thing to establish an EBV-related nasopharyngeal carcinoma animal model is to find a tissue-specific promoter. The EBV ED-L promoter is located in the untranslated region of the 3'end of the LMP-1 gene. It is a keratinocyte-specific promoter. Chemical substances such as TPA can increase its activity by 40 times. Nakagaw et al. constructed cyclin D1 (Cyclin-D1) transgenic animals using ED-L2, a weak promoter that exists within the EBV genome. As a result, the squamous epithelium in the oral cavity, esophagus, and fore stomach of the transgenic animals proliferated abnormally, and Lead to abnormal cell cycle, epidermal growth factor receptor, p53 protein activity. Taking advantage of the characteristic of ED-L2 as a relatively specific promoter of squamous epithelium, the construction of CR2 tissue-specific transgenic mice to express specifically in the mouth and nasopharynx can prepare a mouse model of almost natural infection with EBV. In addition, Huen et al. constructed transgenic mice of EBNA-LP, but did not find that its expression has an effect on the incidence of tumors, and the toxic effect of LP protein may eventually lead to heart failure and death of transgenic animals. Tornell et al. used the SV40 promoter to obtain transgenic animals expressing EBNA-2, and renal tubular proliferative lesions occurred in these animals, which then developed into renal adenocarcinoma. Wilson et al. used the immunoglobulin gene promoter Eμ to obtain EBNA-1 transgenic mice, and lymphomas developed in these mice. Recently, Caldwell et al. constructed transgenic mice expressing LMP2A. Studies have shown that LMP2A can provide B cell receptor-negative B cell survival signals. Kearns-Jonker et al. used immunoglobulin gene promoters to prepare transgenic mice expressing human CR2, and found that less than 5% of peripheral blood B lymphocytes in transgenic mice can be infected with EBV, indicating that EBV can indeed enter through human CR2 In mouse cells. Knockout animals related to EBV receptor CR2 were prepared by Ahearn et al. The B cell function in mice lacking the Cr2 gene locus is extremely impaired, which shows that CR2/1 is essential for B cell function.

　　(3) The research results of comparative medicine serology, epidemiology and molecular biology all show that Epstein-Barr virus is closely related to a variety of human diseases. These diseases mainly include infectious mononucleosis, Burkitt’s lymphoma, and nasopharyngeal disease. Cancer, Hodgkin’s disease, gastric cancer, lymphoproliferative syndrome in immunocompromised hosts, Epstein-Barr virus-associated hematopoietic syndrome, chronic active Epstein-Barr virus infection, T cell lymphoma, natural killer cell leukemia/lymphoma , Empyema-related B-cell lymphoma, smooth muscle tumors, autoimmune diseases, etc. Among them, nasopharyngeal carcinoma (NPC) is a common tumor in China and a tumor with Chinese characteristics. Several southern provinces of China, including Guangdong, Guangxi, Fujian, Hunan and other places, are the high-incidence areas of nasopharyngeal carcinoma in the world. The incidence rate ranks first in the world. With the deepening of research, the role of EBV in the occurrence of NPC has been paid more and more attention. Therefore, the study of EB virus gene structure and function has become the focus of attention in the field of NPC etiology and pathogenesis, and the mechanism of virus entry into cells and The establishment of related animal models has also become a hot topic of research. With the emergence of more and more new methods and the in-depth study of the Epstein-Barr virus, it will be possible to use its relationship to carry out effective gene therapy for these malignant diseases.