Investigating The Mechanisms Of Mercury-induced Autoimmune Response In Different Strains Of Mice

Objective Three strains of different gene backgrounds mice are used to explore the mechanisms of mercury-induced autoimmune response through different doses of mercury chloride and different treat manners.Methods Three adult healthy mice strains,namely BALB/c,SJL and FVB/N,aged 6-8 weeks,were randomly divided into control group and treated groups according to body weight.Two manners of subcutaneous injection of mercuric chloride(HgCl2)and H2Cl2 drinking water were used to treat mice in this study.Mice of treated groups through subcutaneous injection received HgCl2 at dose of 1 mg/kg three times a week and continued for 1-12 weeks.The control group received saline by subcutaneous injection.HgCl2 drinking water experiment was divided into doses experiment and strains experiment.Treated groups of SJL mice received 1,5 and 15 mg/L HgCl2 drinking water for 8 weeks in the doses experiment.Treated groups of BALB/c,SJL and FVB/N mice received 15mg/L HgCl2 drinking water for 5 weeks in the strains experiment.After the experimental period,the organs including spleen,liver and kidney were removed from sacrificed mice,then weighted.Organ coefficient was calculated by the body weight of individual mouse and the weight of respective organ.The level of IgE,the activity of glutamic oxalacetic transaminase and the content of urea nitrogen in serum were detected.The number of spleen cells,apoptosis rate of spleen cells,percentage of splenic B cells(CD 19+ CD3-),percentage of myeloid dendritic cells(CD11chigh MHCⅡ+),percentage of plasmacytoid dendritic cells(CD11clow CD317+),percentage of T cells(CD3+CD19-)and subsets(CD4+T cells、CD8+T cells),and percentage of Treg among CD4+T cells were determined by flow cytometer.Results Subcutaneous injection experiment:the renal organ coefficients of three strains mice were significantly increased after treated.The percentages of T cells,CD4+T cells and CD8+T cells among spleen of BALB/c mice were significantly decreased,while the percentages of Treg,Teff among CD4+T cells and the percentage of splenic B cells were significantly increased.The percentages of Treg among CD4+T cells of FVB/N and SJL mice were increased.Serum IgE levels in all three strains of mice increased significantly.Different doses of drinking water experiment:the renal organ coefficient of group given 15 mg/L HgC1b drinking water was increased.The percentages of Treg among CD4+T cells of groups given 5 mg/L and 15 mg/L HgC1b drinking water were increased,Serum IgE level and the content of urea nitrogen were increased,too.Drinking water experiments of different mouse strains:the renal organ coefficients of BALB/c,SJL and FVB/N mice were increased.The percentage of splenic B cells mice and the percentage of Treg among the CD4+T cells of BALB/c were significantly increased,while the percentages of splenic T cells,CD4+T cells and CD8+T cells were decreased.Serum IgE level and urea nitrogen content of all three strains mice were increased.Conclusion Mercury has an activation effect on CD4+T cells.Different HgCl2 treat manners and gene backgrounds of mice can lead to abnormalities in the proportion of immune cells,these abnormalities may be related to mercury-induced autoimmune response.The content of IgE in FVB/N mice increased significantly after mercury treatment,suggesting that it may be a mercury-sensitive strain.