Study On Immune Memory Induced By Echinococcus Granulosus Infection

Objective The dynamic changes of immune memory in mice infected with Echinococcus granulosus were detected by ELISA and flow cytometry,and the immune memory in the whole process of infection and reinfection was evaluated,which provided research basis and new methods for the prevention and treatment of zoonotic parasitic diseases,including the development of new diagnostic reagents and the search for new treatment strategies.Methods Using random number table method,mice were randomly divided into 3 groups:secondary infection group,infection group and negative control group,with 36 mice in each group.The mice in the negative control group were not treated,and the mice in the secondary infection group and the infection group were injected intraperitoneally with fresh1500/200?l PBS.In the secondary infection group,cysts were removed surgically 6months after infection.Observed 2 months after the surgery and re-infected the protozoan in the same way.Sampled at 6 time points:0,2,4,8,16 and 32 weeks after the reinfection.The infected group was sampled after the infection.Sampling was performed at 6 time points:0,2,4,8,16 and 32 weeks.At each time point,6 mice were randomly sacrificed in each group.ELISA and flow cytometry were performed to observe the mice.Changes in immune memory in the body.The experimental data were analyzed by SPSS 25.0.Results 1 The expressions of Ig G and Ig M in the secondary infection group and the infection group increased rapidly in the initial period and then gradually decreased.The negative control group was relatively stable.There was a significant difference between the three groups?P<0.001?;2 Peripheral blood CD4+T_Mand CD8+T_Mincreased sharply in the early stage of infection and formed a statistical difference with the negative control group?P<0.05?,but there was no statistical difference between the two groups?P>0.05?.With time,the two groups gradually began to decline.However,the secondary infection group continued to have a higher level,which was statistically significant compared with the other two groups?P<0.001?,while the infection group gradually decreased to a statistically significant difference from the negative control group?P>0.05?;3 Peripheral blood T_CMgradually increased during the infection process,with a statistical difference?P<0.05?.Although the nodes at different time periods fluctuated significantly,the expression level of the secondary infection group was always higher than that of the infection group and the negative control group;4 The peripheral blood T_EMincreased rapidly at the beginning of infection.The two groups were significantly different from the negative control group?P<0.001?,and could be maintained for a longer period of time without statistical differences between the two groups?P>0.05?.They all started to decline gradually until there was no significant difference compared with the negative control group?P>0.05?;5 The expression of T_RMin peripheral blood fluctuated to varying degrees between the three groups,although transient statistical differences between groups occurred at different time points?P<0.05?,but the level of expression in the three groups was relatively stable;6 Peripheral blood memory B cells showed a gradual upward trend in the secondary infection group and maintained at a higher level,which was significantly different from the negative control group?P<0.001?.In the early stage,it gradually increased,until there was no significant difference with the secondary infection group?P>0.05?,and then gradually decreased to no statistical difference with the negative control group?P>0.05?;7 Peripheral blood NK cells showed a rapid rise in the early stage of infection There was a statistically significant difference between the second infection and the infected group and the negative control group?P<0.001?,but there was no statistical difference between the two groups?P>0.05?.In the late stage of infection,the second infection group and the infection group showed a gradual increase.Decrease trend until there is no statistical difference with the negative control group?P>0.05?;8 Compared with peripheral blood,the level of changes in flow cytometry in the spleen,lymph nodes,liver,abdominal cavity and other tissues is significantly stable.And no significant differences between organizations.The peripheral blood concentrations of CD4+T_M,CD8+T_M,and T_CMin the secondary infection group,infection group,and negative control group were significantly greater than those in the spleen,lymph nodes,liver,and abdominal cavity,while the concentrations of NK cells in the spleen,lymph nodes,liver,and abdominal cavity were significantly greater than peripheral blood,there were no significant differences in T_EM,T_RM,and memory B cells.Conclusion 1 ELISA test results show that after infection with Echinococcus granulosus,peripheral blood Ig G and Ig M increased rapidly after the initial infection and gradually decreased;2 Flow cytometry results showed that after infection with Echinococcus granulosus,CD4+in peripheral blood The expressions of T_M,CD8+T_M,T_EM,T_CM,memory B cells,and NK cells are different from those of the negative control,while the expression of T_RMis relatively stable;3 Compared with peripheral blood,the spleen,lymph nodes,liver,abdominal cavity and other tissues level of change in cell-type cytometry was significantly stable,and the differences between tissues were not obvious.4 The levels of peripheral blood Ig G and Ig M and CD4+T_M,CD8+T_M,T_EM,T_CM,memory B cells,and NK cells may affect CE.The diagnosis can provide a certain basis.Among them,peripheral blood Ig M and Ig G and T_EMand NK cells may be used as indicators to identify early and late infections;T_CMmay be used as indicators to identify CE first or reinfection;T_RMmay be targeted therapy in the future CE provides some theoretical basis.