Nephritogenicity of antibodies to proteoglycans of the glomerular basement membrane--I.
Nephritogenicity of antibodies to proteoglycans of the glomerular basement membrane--I.
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肾小球基底膜蛋白多糖抗体的肾致炎性--I．
DOI：
10.1172/jci112269
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Kanwar,YS
中科院分区：
文献类型：
--
作者：
Makino,H;Gibbons,JT;Reddy,MK;Kanwar,YS
我们研究了肾小球基底膜硫酸乙酰肝素蛋白聚糖抗体的致肾炎潜力。分离肾小球，制备基膜，提取蛋白多糖，获得纯化的核心蛋白。用核心蛋白和制备的抗血清免疫家兔，并测定了抗体的特异性。在琼脂扩散板上可见单个免疫印迹线，在免疫印迹放射自显影图上可见单个条带（约18，000 mol wt）。该抗体显示出与肾小球基底膜的精确反应性。清除研究表明，大约75%的放射性碘标记抗体在1小时内从循环中消失，1-2%与肾脏结合。对于致肾炎实验，将抗体静脉内给予大鼠，并在1 h至24 d后检查其肾脏。兔IgG免疫荧光染色显示肾小球基底膜免疫荧光呈线性，C3免疫荧光染色至第10天仍呈线性。早期形态学改变包括肾小球多形核白细胞浸润伴局灶性内皮细胞剥脱。白细胞浸润消退的第三天，其次是进行性增厚的基底膜，局灶性系膜细胞增殖，系膜基质的增加，单核细胞的积累。从第15天开始观察到肾小球基底膜的局灶性结节样增厚。在肾小球基底膜的内层和外层可见规则间隔的电子致密沉积物，并持续整个排泄期。在实验的任何阶段均未观察到显著的蛋白尿。这些发现表明，基底膜硫酸乙酰肝素蛋白聚糖的抗体具有肾毒性，但具有较弱的致肾炎潜力。图片
We investigated nephritogenic potential of antibodies to heparan sulfate-proteoglycan of glomerular basement membrane. Glomeruli were isolated, basement membranes were prepared, proteoglycans extracted, and purified core protein was obtained. We immunized rabbits with the core protein, IgG fraction prepared from the antisera and specificity of the antibody determined. A single immunoprecipitin line in agar diffusion plate and a single band (approximately 18,000 mol wt) on the immunoblot autoradiograms were visualized. The antibody showed precise reactivity with the glomerular basement membranes. The clearance studies indicated that approximately 75% of the radioiodinated antibody disappeared from circulation within 1 h and 1-2% bound to the kidney. For nephritogenicity experiments, the antibody was intravenously administered into rats and we examined their kidneys at 1 h to 24 d later. A linear immunofluorescence of glomerular basement membranes was observed with rabbit IgG at all times while that of C3 until the 10th day. Early morphologic changes included glomerular infiltration of polymorphonuclear leukocytes with focal exfoliation of endothelium. The leukocytic infiltration subsided by the third day and was followed by progressive thickening of basement membranes, focal mesangial cell proliferation, increase in mesangial matrix, and accumulation of monocytes. Focal knob-like thickening of glomerular basement membrane was observed from the 15th day onward. Regularly-spaced electrondense deposits were seen in the lamina rara interna and externa of glomerular basement membranes and persisted throughout the investigatory period. No significant proteinuria was observed at any stage of the experiment. These findings suggest that the antibodies to the basement membrane heparan sulfate-proteoglycan are nephrotoxic but possess weak nephritogenic potential.Images