疾病动物模型,类风湿性关节炎 z-bio 2021-03-11 239

　　(1) Human tumor necrosis factor transgenic mouse model

　　[Modeling mechanism] Tumor necrosis factor-α (TNF-α) is mainly secreted by activated macrophages, and a small amount of activated T cells, NK cells and mast cells are also secreted. The TNF-α specific membrane receptors are present in almost all cell types. TNF was first discovered to be related to tumors, and it is now clear that it is an immune modulator of normal and chronic inflammation.

　　"It has been found that the levels of TNF-α, IL-1 and IL-6 in the synovial fluid of RA patients are elevated, indicating that the pathogenesis of RA is related to TNF-α. The expression of human TNF-α gene in mice can partially mimic the clinical manifestations of RA.

　　【Modeling method】Contains the complete human TNF-α gene and the 5'end 0.6kb sequence to recombine with the 3'untranslated region and polyadenylation site of the human β-globin gene to form a TNF-globin recombinant DNA fragment. This modification provides the necessary polyadenylation signal and does not interfere with the normal translation of wild-type human TNF. This recombinant DNA fragment was microinjected into (CBA×C57B1/6) F1 mouse fertilized eggs, and the RA transgenic mouse model was obtained after screening in the first established mouse.

　　【Characteristics of the model】The main clinical manifestations of this model are swelling of the ankle joint and dyskinesia, and it is 100% inherited to the next generation. At the age of 3 to 4 weeks, the symptoms began to be obvious, the ankle joint swelled, and synovial hyperplasia was observed at this time. Before 5 weeks of age, the ankle joint was swollen, and the synovial membrane under the microscope was obviously hyperplasia and inflammation. At 9 to 10 weeks of age, the limb dyskinesia develops to the complete loss of movement of the hind limbs. Weight loss is a common feature of these mice.

　　Histopathological examination showed that the lesion showed bilateral symmetrical polyarthritis, synovial hyperplasia from 3 weeks of age, polymorphonuclear nucleus and lymphocyte infiltration in the synovial space were obvious in all joints at different stages of development. In addition, the formation of pannus, the destruction of articular cartilage, and the formation of fibrous tissue are all very similar to human RA.

　　However, no rheumatoid factor or rheumatic nodules were found in the serum at all stages of the disease in this model mouse, which is different from human RA.

　　【Model Evaluation and Application】The TNF model can be used to study the pathogenesis of rheumatoid arthritis, autoimmune pathology, and the pharmacodynamics of rheumatoid arthritis drugs.

　　(2) Human IgGFc receptor transgenic RA mouse model

　　[Modeling mechanism] The human FCGR2A gene encodes the Fc receptor of IgG. The human FCGR2A gene is introduced into the mouse. The product of the human FcgRIIA R131 gene encoding human FcgRIIA R131 can bind to various subclasses of mouse IgG. This strain of mice expresses human FCGR2A on platelets and macrophages, and the expression level is similar to that of humans.

　　[Modeling method] A 72kb DNA fragment was screened from the human P1 genome library by PCR, of which 20kb is the FCGR2A gene, 45kb is the 5'flanking region containing the promoter, and 7kb is the 3'flanking region. This DNA fragment was microinjected to prepare transgenic mice, and the foreign genes were randomly integrated into the mouse genome.

　　【Features of the model】About 32% of mice of this strain develop spontaneous arthritis at 20-50 weeks of age. It is characterized by stiffness of the joints, narrowing of the joint space, and formation of new bone around the joint; synovial hyperplasia, cartilage corrosion, pannus formation, and joint space infiltration. Such strains of mice are immunized with collagen or injected with anti-collagen antibodies, which can prematurely develop disease and increase the proportion of diseased mice.

　　Progressive glomerulonephritis develops as the age of the mice grows. Severe glomerulonephritis develops in all mice at 40 weeks. Immune complex deposits in the kidney, glomerulus enlargement, and mesangial matrix proliferation. But as long as the kidney function is not damaged, glomerulonephritis is self-limiting.

　　12-40 weeks old mice develop interstitial pneumonia as they age, and severely ill patients with lung structure obstruction. In response to the aggregation of globulin, the production of TNF-α increased by 6.5 times in macrophages.

　　[Model Evaluation and Application] This model can be used for the pathogenesis of rheumatoid arthritis, autoimmune pathological regulation, and pharmacodynamic research of rheumatoid arthritis drugs. In addition, it can also be used for research on the pathophysiology of macrophages and antibody-mediated thrombocytopenia.

　　TNF-α transgenic and human IgGFc receptor transgenic RA mouse model was established to simulate the pathogenesis of human RA, and its pathological changes are similar to RA. However, human RA is a systemic autoimmune disease controlled by multiple genes, and the introduction of a single gene only partially mimics the clinical manifestations of human RA.

　　"In addition, as the F1 generation of NZB and NZW mice, NZBWF1/J mice can also spontaneously develop arthritis and produce IgM and IgG autoantibodies similar to human RA.