动物实验,新冠患者 z-bo 2020-10-13 301

　　According to epidemiological data, patients infected with the new coronavirus (SARS-CoV-2) have a higher illness and mortality rate among the elderly. 80% of deaths in intensive care units are over 60 years old, 62% of hospitalized patients are over 55 years old, and 53% of patients are over 65 years old. Therefore, the elderly are now considered to be the most important risk factor for death from the new coronavirus infection. In the older red-spot monkey disease model, the new coronavirus infection is essential for studying the pathogenesis, etiology and treatment strategies of elderly patients with new coronary pneumonia.

　　Recently, the Kunming Institute of Zoology, Chinese Academy of Sciences established a SARS-CoV-2 infection model for Chinese macaques and compared their etiology. As a result, 1 week after infection, the lung virus load of juvenile red-tailed monkeys was significantly higher than that of juvenile red-tailed monkeys. Two weeks after infection, the lung virus load of juvenile red-tailed monkeys was significantly reduced, but the viral load of juvenile red-tailed monkeys was significantly reduced. The amount is reduced evenly. I have no pathological results of the lungs. Compared with the older mackerel, the young mackerel showed more obvious pulmonary hemorrhage and immune cell infiltration 1 week after infection, while the young mackerel showed 2 weeks after infection. Out of interstitial pneumonia. The old Makaku showed his trachea. A large number of immune cells penetrated into the surrounding blood vessels, indicating that the lung immune damage of adult red-tailed monkeys lasted up to two weeks after infection.

　　13 kinds of cytokines were detected in lung tissue, and one week after infection, the average concentration of most cytokines in the lungs of young red-tailed monkeys was higher than that of older red-bellied monkeys, but after infection, old age The red-tailed monkeys have higher lung cytokine concentrations. higher. The second week was significantly higher than the young Makaku. Compared with 1 week after infection, the lung cytokine concentration of young red-tailed monkeys decreased 2 weeks after infection, while the lung cytokine concentration of old red-tailed monkeys increased significantly. Therefore, the older Makaku developed a more severe cytokine storm two weeks after infection. Immunofluorescence experiments (Figure C) showed that the number of immune cells in the lungs of young red-tailed monkeys decreased 2 weeks after infection, and with the continuous infiltration of CD8 + T cells, the infiltration of CD11b + cells in the lungs of young red-tailed monkeys increased. It has been confirmed. Evaluation of T cell activation, regulation and function in peripheral blood (Figure D) showed that the two groups of animals increased T cell differentiation and expressed marker proteins related to immune activation after SARS-CoV-2 infection. It was found to increase. Compared with young red lizards, the proportion of IFN-γ+CD8+ T cells, TNFα+CD4+ T cells and TNFα+CD8+ T cells in the peripheral blood of old red lizards increased significantly 2 weeks after infection. many. Many pro-inflammatory cells enter the lungs and cause continuous immune damage.

　　The above results indicate that delayed but more severe cytokine storm and immune cell infiltration may be the reason for the poor prognosis of elderly patients newly infected with coronavirus.