T淋巴细胞缺陷,动物模型,动物造模 z-bio 2021-11-06 825

　　The clinical manifestations of animals with T lymphocyte immune dysfunction are lack of hair and hypoplasia of thymus. In 1966, a mutant spontaneous hairless mouse was discovered in a group of Scottish mice. Mice grow poorly, reproduce poorly and are susceptible to severe infections. By 1968, hairless mice were continuously cut off in the mediastinum. The thymus allows the animal to receive transplantation of allogeneic or heterologous tissue. There are a variety of hereditary weakness animals, including nude mice, nude mice, nude guinea pigs, and genetic weakness mouse models. The most common animals with defective T lymphocyte function are nude mice and rats.

　　(1) nude mouse

　　nude mice are congenital athymic nude mice with defective T lymphocyte function. The naked gene (nu) that causes this abnormal condition is a stable mutant gene on chromosome 11. Naked genes have been introduced into multiple mouse strains with different genetic backgrounds through backcrossing, such as BALB/c-nu and C57BL/6-nu. Due to different genetic backgrounds, different nude mouse strains exhibit different cell-mediated immune responses and experimental laboratory indicators. The main characteristics of nude mice are hairlessness, nudity and adenopathy. As the mice age, the skin becomes thinner, the skin on the head and neck becomes wrinkled, and growth slows down. Due to the existence of the thymus, there are only thymus fragments or abnormal epithelium, which cannot differentiate T cells normally, and lacks the auxiliary, inhibitory and killing functions of mature T cells, resulting in low cell-mediated immunity. Due to the defects of T lymphocytes, T cell functions cannot be performed normally. The mixed lymphocyte reaction has no mitotic response to concanavalin A or plant lectin P, no cytotoxic effector cells, and no mitogen reaction. No exposure to hypersensitivity or transplant rejection. The B lymphocytes in nude mice are normal but not functional. Immunoglobulins are mainly IgM and only contain a small amount of IgG. Adult nude mice (6-8 weeks) have higher NK cell activity levels than normal mice, while young mice (3-4 weeks) have lower NK cell activity levels. Due to their low resistance and sensitivity to viral hepatitis and pneumonia, nude mice have relatively strict requirements for feed and reproduction, and can survive in an SPF environment. The cage, bedding, feed, drinking water, etc. used are indispensable. The bacteria are sterilized and stored in an isolator to ensure long-term survival and reproduction. Homozygous female nude mice nu/nu have a low conception rate, poor mammary gland development and feeding habits, so homozygous male mice and heterozygous female mice usually mate and reproduce to produce 1/2 homozygous offspring.

　　(2) Ratnuderat of nude mice) was first discovered in 1953 by the Rowtt Institute in the United Kingdom. The genetic symbol is rnu. When reared in a normal environment, it can only be maintained for 15 to 16 generations. In 1975, homozygous nude mice (rnu/rnu) were rediscovered and confirmed to belong to autosomal recessive inheritance. In 1977, the British MRC Laboratory Animal Center established a nude mouse seed group. In 1987, nude mice were described in detail for the first time, and human cancer xenotransplantation in nude mice was reported. In 1976, the University of Victoria in New Zealand discovered another naked mole rat. McNee Large reported in detail in 1979. The genetic symbol is Nznu. It was launched in China in 1983. The histology of the immune system of nude mice is very similar to that of nude mice. After 3 weeks, serial sections of the mediastinum of nude mice showed only thymus fragments and no lymphocytes. In fact, there are no lymphocytes in the paracortical area of the lymph node, and the function of T lymphocytes has been lost. The general characteristics of nude mice are similar to nude mice, but the hair on the torso is sparse. It is not completely hairless like a nude mouse. There is a lot of hair on the head and limbs. The method of reproduction is the same. Nude mouse. Hadakadebanezumi is susceptible to respiratory diseases (ulcerative tracheobronchitis and suppurative bronchopneumonia, the cause may be related to Sendai virus infection). The discovery of nude mice and the successful xenotransplantation of human cancer have added new methods to tumor immunology research. Using nude mice instead of nude mice has certain advantages over nude mice, because it has the advantages of large transplanted tumors, high blood volume, and fewer operations, but the maintenance cost is higher than that of nude mice, and the disadvantage is that it is expensive.