Pathogenic analysis for autoimmune and hereditary skin diseases due to abnormality of desmosomes

通过免疫荧光技术，利用转染人黏菌素1-3 cdna的COS-7细胞，我们发现一些天疱疮血清中含有与黏菌素反应的IgA抗体。IgA天疱疮有两种亚型，IEN型和SPD型。通过免疫电镜研究，我们发现SPD型IgA天疱疮的IgA抗体与桥粒区反应，而IEN型IgA天疱疮的IgA抗体与非桥粒区反应。我们发现大多数IgG/IgA天疱疮血清中IgG和IgA抗体与Dsg1/Dsg3和Dsc1反应。此外，通过免疫电镜研究表明，这些血清与桥粒区域反应。我们检查了一个大家族，患者在基底层以上表现为棘溶性水泡。首先，我们检查了粘粒蛋白3基因，但没有发现突变。然而，我们在编码SERCA2的ATP2A2基因中发现了突变，SERCA2是达里尔病的致病基因。在表皮浅表水疱形成的病人中，我们没有检测到桥粒体蛋白基因的任何突变。相反，在这个病人身上，我们发现了角蛋白1基因c端区域的突变。我们已经制备了多种包膜蛋白和外包膜蛋白的重组蛋白。通过使用这些重组蛋白的免疫印迹，我们已经表明大多数副肿瘤天疱疮患者与包膜蛋白和periplakin的不同结构域发生反应。我们成功地培育出了desmoyokin基因敲除小鼠。桥粒未见形态学异常。此外,。敲除小鼠的细胞培养未出现异常的细胞粘附。

By immunofluorescence using COS-7 cells transfected with cDNAs of human desmocollins 1-3, we have shown that some pemphigus sera contained IgA antibodies reactive with desmocollins. There are two subtypes of IgA pemphigus, IEN type and SPD type. By immuno-electron microscopic study, we have shown that IgA antibodies of SPD type IgA pemphigus reacted with desmosomal areas, whereas IgA antibodies of IEN type IgA pemphigus reacted with non-desmosomal areas. We have shown that most of the sera of IgG/IgA pemphigus had IgG and IgA antibodies reactive with Dsg1/Dsg3 and Dsc1. In addition, by immuno-electron microscopic study, it is shown that these sera reacted with desmosomal areas. We have examined a large family with patients showing acantholytic blister above the basal layer. First, we examined desmoglein 3 gene, but we could not find a mutation. However, we have found a mutation in the ATP2A2 gene, encoding SERCA2, the causative gene of Darier disease. In a patient showing superficial blister formation in the epidermis, we have not detected any mutations in the genes of desmosomal proteins. In stead, in this patient, we have found a mutation in the C-terminal area of keratin 1 gene. We have produced various recombinant proteins of envoplakin and periplakin. By immunoblotting using theses recombinant proteins, we have shown that most paraneoplastic pemphigus patients reacted with various domains of envoplakin and periplakin. We have succeeded to produce knockout mice of desmoyokin. We could not find any morphological abnormality in the desmosomes. In addition,. the cell culture from the knockout mice did not show an abnormal cell adhesion.