核自身抗原精子蛋白(NASP)基因突变加重诱导型狼疮模型小鼠自身免疫应答

Mutation of nuclear autoantigenic sperm protein(NASP)gene aggravates autoimmune response in induced lupus model mice

目的制备诱导型狼疮模型小鼠,探讨核自身抗原精子蛋白(NASP)基因突变对诱导型系统性红斑狼疮(SLE)模型小鼠自身免疫应答的影响。方法3月龄野生型B6(B6-WT)小鼠为对照组、NASP基因突变B6(B6-NASPM)小鼠为实验组。用伴刀豆球蛋白A(ConA)活化小鼠的脾脏淋巴细胞,提取其DNA为自身抗原,分别免疫B6-WT小鼠和B6-NASPM小鼠3次。EUSA检测血清抗双链DNA(dsDNA)IgG水平,HE染色检测肾脏病变情况,免疫荧光组织化学染色检测肾组织IgG和补体C3的沉积情况。流式细胞术比较B6-WT小鼠和B6-NASP^M小鼠的脾脏淋巴细胞亚群变化,从而探讨NASP基因突变影响小鼠免疫应答的机制。结果与B6-WT小鼠相比,B6-NASP^M小鼠体质量、肾脏指数和脾脏指数均无明显变化,其血清抗dsDNA IgG水平明显升高,肾小球细胞增生明显、IgG以及C3的沉积增加。脾脏CD3+T细胞、自然杀伤(NK)细胞比例降低、CD19+B细胞、调节性B细胞(Breg)比例增加。结论NASP基因突变促进小鼠产生更高水平的抗dsDNA IgG,促进肾脏肾小球内细胞增生、IgG及C3的沉积,并改变小鼠脾脏的免疫细胞的比例,加重狼疮模型小鼠的自身免疫应答。

Objective To prepare inducible lupus model mice and investigate the effect of nuclear autoantigenic sperm protein(NASP)gene mutation on the autoimmune response of mice with induced systemic lupus erythematosus(SLE).Methods The 3-month wild-type B6(B6-WT)mice were used as a control group and the NASP mutant B6(B6-NASP^M)mice as an experimental group.Mouse spleen lymphocytes were activated with concanavalin A(ConA),and the DNA was extracted as autoantigen.B6-WT mice and B6-NASP^M mice were immunized three times.Serum anti-double stranded DNA(dsDNA)IgG levels were detected by ELISA.Renal lesions were detected by HE staining.Immunohistochemical staining was performed to detect the deposition of IgG and complement C3 in the renal tissues.Flow cytometry was applied to compare the spleen lymphocyte subsets in B6・WT and B6-NASP^M mice and to explore the mechanism of NASP gene mutation affecting the immune response in mice.Results Compared with B6・WT mice,B6-NASP^M mice showed no significant cha nges in body weight,kidney in dex and splee n in dex;serum anti-dsDNA IgG levels sign ifica ntly in creased;glomerular cell proliferation was obvious and the deposit!on of IgG and C3 in the renal tissues in creased.The proporti on of spleen CD3+T cells and natural killer(NK)cells decreased,while the proportion of CD19+B cells and regulatory B cells(Breg)increased.Conclusion Mutation in the NASP gene can increase the levels of anti-dsDNA IgG antibodies,promote cell proliferation in the glomerulus of the kidney,deposition of IgG antibodies and complement C3,alter the proportion of immune cells in the spleen and aggravate the autoimmune response in lupus model mice.