Analysis Of Superior Antibodies That Resistance The Invasion Of Plerocercoids In Mice Infected With Plerocercoids At Different Times

Objective:To dynamically detect the superior antibody types in mice infected with plerocercoids,and to understand the role of specific antibody in resistance to plerocercoids invasion,migration and colonization.Methods:1.Establishment of a mouse model infected with plerocercoids and preparation of test specimens:?120 kunming mice were randomly divided into 16 groups,including 8 experimental groups(10 mice/each group)and 8 control groups(5 mice/each group).Mice in the experimental group were orally infected with plerocercoids(5 worms/per mouse).The control group mice was not infected,and the feeding conditions were the same as the experimental group.?A group of 10 infected mice was randomly killed at designed time points from 6 hours to 126 days.Autopsy was performed on each mouse to recover the plerocercoids.?Small intestine fluid,peritoneal fluid,serum,samples from the experimental group and the control group was collected 6h-126d after infection.2.Detection of specific antibodies:?Double antibody ELISA sandwich method was used to detect the level of sIgA in mouse small intestinal fluid.?Indirect ELISA method was used to determine the specific antibodies(different types or subclass)in peritoneal fluid and serum.Results:1.After 6 hours of infection,the larvae was mainly distributed in the gastrointestinal cavity,gastrointestinal wall and abdominal cavity.One day after infection,most larvae enter the abdominal cavity through the gastrointestinal wall.After 7 days post infection,most larvae migrated to the subcutaneous tissues,and the number of larvae decreased with the extension of infection time.2.Detection of sIgA in small intestine fluid:The level of sIgA in small intestine fluid increased after infection in mice,reached a peak at 7d[(22.05±1.43)?g/mL],then decreased to the pre-infection level at 56d.3.Detection of antibodies in peritoneal fluid:Peritoneal fluid IgA and IgE were not detected at all time points after infection.4.Detection of antibodies in serum:?IgM was detected at 7d after infection(0.551±0.120),then increased from 7-28d,reached peak at 28d(0.865±0.228),and maintain a high level to 56d,then fell to the normal level after infection 91d.?IgG was detected at 14 days after infection(0.724±0.323),and increased at 14-56d,reached peak at 56d(2.435±0.088),then detected until 126d.?Serum IgA and IgE were not detected at all time points after infection.?From 14 to 126d after infection,IgG subclasses(IgG1,IgG2b,IgG2c,IgG3)were not detected.Conclusion:1.Detection of slgA in small intestine fluid showed that immune response of small intestinal mucosa in infected mice could be induced to a certain extent.Because of the small amount of slgA and the later production than the invasion time of plerocercoids,so slgA could not effectively resist worm invasion.2.The dynamic changes of serum IgM and IgG in mice indicated that the immune responses mediated by these two antibodies participated in the process of resisting migration and settlement of plerocercoids to a certain extent.3.IgG was the dominant antibody in serum,which was related to the decrease of the number of plerocercoids.