Generation of novel covalent RNA-protein complexes in cells by ultraviolet B irradiation - implications for autoimmunity
Generation of novel covalent RNA-protein complexes in cells by ultraviolet B irradiation - implications for autoimmunity
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DOI：
10.1002/art.20992
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发表时间：
2005-04-01
影响因子：
--
通讯作者：
Rosen, A
中科院分区：
文献类型：
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作者：
Andrade, F;Casciola-Rosen, LA;Rosen, A
Objective.为了确定紫外线B（UVB）照射是否诱导实验性光诱导表皮损伤过程中靶向自身抗原的新修饰。为了寻找新的UVB诱导的自身抗原修饰，从UVB照射的人角质形成细胞或HeLa细胞制成的裂解物使用识别核糖核蛋白自身抗原的人自身抗体进行免疫印迹。用核酸酶和RNA杂交进一步鉴定新的自身抗原结构。通过免疫印迹识别U1-70 kd（U1- 70 K）和La的人血清在用于UVB照射的角质形成细胞或HeLa细胞的裂解物的免疫印迹时也识别多个新物种。这些物种不存在于对照细胞中，没有观察到凋亡诱导Fas连接或细胞毒性淋巴细胞颗粒内容。多项生化分析表明，U1 RNA和hYRNA分子与其相关蛋白（包括U1- 70 K、La和Sm颗粒的可能组分）之间的共价交联导致了这些新的UVB诱导的分子种类。这些数据表明，UVB照射活细胞可以直接诱导共价RNA-蛋白质复合物，其被人自身抗体识别。如前所述的其他自身抗原，这些共价复合物的RNA和蛋白质可能有重要的后果，在抗原捕获和加工。
Objective. To determine whether ultraviolet B (UVB) irradiation induces novel modifications in autoantigens targeted during experimental photoinduced epidermal damage.Methods. To search for novel UVB-induced autoantigen modifications, lysates made from UVBirradiated human keratinocytes or HeLa cells were immunoblotted using human autoantibodies that recognize ribonucleoprotein autoantigens. Novel autoantigen structures identified were further characterized using nucleases and RNA hybridization.Results. Human sera that recognize U1-70 kd (U1-70K) and La by immunoblotting also recognized multiple novel species when they were used to immunoblot lysates of UVB-irradiated keratinocytes or HeLa cells. These species were not present in control cells and were not observed when apoptosis was induced by Fas ligation or cytotoxic lymphocyte granule contents. Biochemical analysis using multiple assays revealed that these novel UVB-induced molecular species result from the covalent crosslinking between the U1 RNA and the hYRNA molecules with their associated proteins, including U1-70K, La, and likely components of the Sm particle.Conclusion. These data demonstrate that UVB irradiation of live cells can directly induce covalent RNA-protein complexes, which are recognized by human autoantibodies. As previously described for other autoantigens, these covalent complexes of RNA and proteins may have important consequences in terms of antigen capture and processing.