动物造模,诺如病毒 z-bio 2022-04-27 507

　　Objective To study the changes of total IgG antibody and neutralizing antibody after infection with mouse norovirus in 5 strains of mice including KM, BALB/c, NIH, C57BL/6J and BALB/c-nu.

　　Methods Five strains of mice, KM, BALB/c, NIH, C57BL/6J and BALB/c-nu, were collected, and each strain was divided into control group and infection group. volume of normal saline (ie, 0.9% NaCl solution). Blood was collected from 1 to 9 weeks after infection to separate serum, ELISA was used to determine the level of total IgG antibody (i.e. absorbance value), and RAW264.7 cytopathic method was used to determine the neutralizing antibody titer (i.e. the median protective dose, PD50). The t test was used to compare the difference in the mean absorbance of total IgG antibody between the infection group and the control group at each time point; one-way analysis of variance was used to compare the total antibody and neutralizing antibody titers of the infection groups of each strain of mice, and to analyze the change rule of the antibodies of each strain of mice .

　　Results By t test, the mean absorbance of total IgG antibody in KM, BALB/c, NIH, C57BL/6J and BALB/c-nu mice on the 21st, 35th, 14th, 14th and 28th days in the infection group was significantly higher than that in the control group ( P < 0.01). Compared with the total IgG antibody levels of each line of mice, NIH>C57BL/6J>KM>BALB/c>BALB/c-nu, and the mean absorbance of BALB/c and BALB/c-nu total antibodies was significantly lower than NIH and C57BL /6J mice (P＜0.05); NIH, C57BL/6J, KM and BALB/c mice increased rapidly at the 6th week of infection, and the NIH mice entered the plateau on the 49th day, and the remaining 3 strains were small The total IgG antibody level of mice was still on an upward trend in the experimental period, and the total antibody level of BALB/c-nu mice was the lowest. Comparison of neutralizing antibody titers of various strains of mice, C57BL/6J > NIH > KM > BALB/c > BALB/c-nu, the mean values of lgPD50 were 3.881, 3.819, 3.746, 3.146 and 2.338 respectively; The neutralizing antibody titers of BALB/c and BALB/c-nu mice were significantly lower than those of C57BL/6J, NIH and KM mice (P＜0.01). Except for BALB/c-nu mice, the neutralizing antibody titers of the other four strains of mice increased rapidly at the second week of infection, and the neutralizing antibody level of BALB/c-nu mice was always at a low level.

　　Conclusion The humoral immune response of NIH, C57BL/6J and KM mice infected with MNV is stronger, while the humoral immune response of BALB/c and BALB/c-nu mice is weaker.