Untersuchungen zur biologischen Rolle von neuen Kazal-typ Inhibitoren LEKTI-2 und LEKTI-3

对健康皮肤角质层的抗微生物肽的分析导致发现了两种新的“淋巴上皮Kazal型”蛋白酶抑制剂（LEKTI-2和LEKTI-3）。重组LEKTI-2具有抗微生物特性，并且是激肽释放酶5（KLK-5）的选择性抑制剂，而重组LEKTI-3缺乏抗微生物活性，但对胰蛋白酶KLK 5和胰凝乳蛋白酶KLK 7均表现出强效抑制活性。这两种蛋白酶在表皮脱屑中具有重要作用，这在内瑟顿综合征中受到干扰，内瑟顿综合征是一种炎症性皮肤病，由于LEKTI-1基因缺陷导致LEKTI-1缺乏而破坏皮肤屏障。这在LEKTI-1 k.o.-为了研究两种新的LEKTI在脱屑中是否具有相似的重要性，将产生LEKTI-2-以及后来的LEKTI-3敲除小鼠以及过表达这些LEKTI的转基因小鼠。在我实验室的这个合作项目中，将克隆小鼠LEKTI-2和-3同源物，分析其在小鼠中的组织表达，然后重组表达用于分析抗微生物和蛋白酶抑制特性，特别是用于抑制脱屑相关的激肽释放酶。我们将进一步生成用于免疫组织化学的mLEKTI-2和-3-抗体以及LEKTI-2-和3-的ELISA，以分析其在各种小鼠模型脱屑中的作用。

Analyses of healthy skin stratum corneum for antimicrobial peptides led to the discovery of two novel „lympho-epithelial Kazal-Type” protease inhibitors (LEKTI-2 and LEKTI-3). Whereas recombinant LEKTI-2 has antimicrobial properties and is a selective inhibitor of Kallikrein 5 (KLK-5), recombinant LEKTI-3 lacks antimicrobial activity, but exhibits potent inhibitory activities against both, tryptic KLK5 and chymotryptic KLK7. These two proteases have an essential role in the epidermal desquamation, which is disturbed in Netherton-Syndrome, an inflammatory skin disease with disrupted skin barrier due to a LEKTI-1 gene defect that causes LEKTI-1 deficiency. This was proven in LEKTI-1 k.o.- mice, which show a phenotype resembling Netherton syndrome patients.To study whether both novel LEKTIs are of similar importance in desquamation, LEKTI-2- und later also LEKTI-3 knock-out mice as well as transgenic mice overexpressing these LEKTIs will be generated. In this cooperation project in my laboratory murine LEKTI-2- and -3 orthologs will be cloned, its tissue expression in mice analysed and then recombinantly expressed for analyses of antimicrobial and protease-inhibiting properties, in particular for inhibition of desquamation-relevant kallikreins. We will further generate mLEKTI-2 and -3-antibodies for immunohistochemistry and ELISAs for LEKTI-2- and 3- to analyse its role in desquamation of various mouse models.