耐性肽hCDR1诱发小鼠狼疮样病变的研究

Tolerizing peptide h CDR1 induces lupus-like symptom in mice

目的探讨基于人dsDNA抗体分子互补决定区1(CDR1)的耐受肽(tolerizing peptide)hCDR1作为致病原诱发小鼠狼疮样病变的可能。方法 6-8周龄B6D2F1雌性小鼠40只,随机分为hCDR1 20μg组、100μg组、500μg组、阴性对照组和阳性对照组。完全弗氏佐剂乳化hCDR1,足跖及尾根部多点皮下注射免疫h CDR1组小鼠,间隔3周,不完全弗氏佐剂乳化hCDR1加强免疫1次;阴性对照组用不含hCDR1的佐剂皮下免疫,阳性对照组小鼠接受DBA/2小鼠脾脏及胸腺单细胞悬液尾静脉注射形成慢性移植物抗宿主样狼疮鼠(SLE-c GVHD)。尿蛋白试纸监测小鼠每周蛋白尿变化。首次免疫后9周采血,检测血液常规;ELISA法检测血清中h CDR1抗体、dsDNA抗体、组蛋白抗体及总IgG抗体;留取肾脏,直接免疫荧光检测肾脏免疫复合物沉积情况;HE染色观察肾脏病理改变。结果 hCDR1 100μg组和500μg组小鼠出现狼疮样改变。与阴性对照组相比,100μg组小鼠和500μg组小鼠血清dsDNA抗体、组蛋白抗体OD值增加(P<0.05);外周血血小板减少(P<0.05),白细胞增加(P<0.05);75%小鼠出现狼疮样肾脏改变,表现为尿蛋白阳性,肾小球增生以及肾小球基底膜IgG免疫复合物的沉积。20μg剂量组小鼠及阴性对照组小鼠未出现狼疮样改变。结论 hCDR1具有免疫原性,可以作为致病原诱发B6D2F1小鼠出现狼疮样病变。

Objective To explore the possibility of hCDR1,a peptide based on the complementarity determining region（ CDR）1 of a human monoclonal anti-DNA autoantibody,inducing an SLE-like disease in B6D2F1 mice. Methods Forty B6D2F1 mice were divided into five groups randomly：hCDR1 20 μg group,100 μg group,500 μg group,normal control group and positive control group[chronic graft versus host disease murine model of lupus（ SLE-c GVHD）]. Mice were subcutaneously injected with 0. 2 ml hCDR1 in hCDR1 groups and 0. 2 ml adjuvant in normal control group. SLE-c GVHD was induced by intravenous injections of parental female DBA /2 lymphocytes. The serum hCDR1 antibody,anti-ds DNA antibody,anti-histone antibody and total Ig G were detected by ELISA. Kidney specimens were observed by immunofluorescence and histological examination. Results SLE-like symptoms were successfully induced by hCDR1 in 100 μg group and 500 μg group. Compared with normal control group,mice in 100 μg group and 500 μg group acquired higher OD value of ds DNA antibodies（ P〈0. 05） and anti-histone antibodies（ P〈0. 05）. Compared with normal control group,peripheral blood PLT significantly decreased,while peripheral blood WBC increased in 100 μg group and 500 μg group（ P〈0. 05）. In 100 μg group and 500 μg group,75% mice got nephritis characterized by proteinuria and immunocomplex deposition in glomeruli. No SLE-like symptom was detected in 20 μg hCDR1 immunized mice and normal control mice. Conclusion SLE-like symptom could be induced by hCDR1 in B6D2F1 mice.