Protease-mediated regulation of host immune system and application as therapeutic targets

在这项研究中，我们研究了宿主和细菌来源的蛋白酶在宿主免疫系统中的性质和功能。组织蛋白酶E （catE）和牙龈蛋白酶分别作为宿主源性内溶酶体蛋白酶和细菌蛋白酶处理。所得结果如下：(1) CatE对树突状细胞和巨噬细胞的性质和功能有差异调节；(2)CatE缺乏导致巨噬细胞自噬受损，表现为线粒体功能障碍和氧化应激增强；(3)内源性CatE表达水平与体内肿瘤细胞生长停滞和转移减少以及肿瘤微环境中肿瘤相关活化巨噬细胞的增加呈正相关。（iv）通过催化可溶性TRAIL从肿瘤细胞表面蛋白水解释放，在体外不影响正常细胞的情况下特异性诱导肿瘤细胞凋亡；(v)通过cDNA展示技术生成基于肽-适体体的CatE抑制剂和激活剂；（vi） Arg-gingipain （Rgp）选择性蛋白水解载脂蛋白B-100介导的P. gingivalis感染加速载脂蛋白e敲除小鼠动脉粥样硬化进展。（vii）妊娠小鼠的早产和胎儿死亡风险因牙龈卟啉卟啉感染而增加，而Rgp和Kgp抑制剂联合治疗可抑制。（iii）新开发的抑制Rgp和Kgp的肽类似物可抑制牙龈卟啉卟啉卟啉的大部分致病性。

In this study, we investigated the nature and function of both host-and bacteria-derived proteases in host immune system. Cathepsin E (catE) and gingipains were treated as a host-derived endolysosomal protease and bacterial proteases, respectively. The obtained results are as follows : (i) CatE differentially regulated the nature and function of dendritic cells and macrophages, (ii) CatE deficiency caused impairment of autophagy in macrophages manifesting mitochondria dysfunction and enhanced oxidative stress, (iii) Endogenous Cat E expression levels were positively associated with the growth arrest and metastasis reduction of tumor cells in vivo and the concomitant increase of tumor-associated activated macrophages in tumor microenvironment, (iv) CatE specifically induced apoptosis in tumor cells without affecting normal cells in vitro by catalyzing the proteolytic release of soluble TRAIL from tumor cell surface, (v) Peptide-aptamer-based inhibitors and activators of CatE was generated by cDNA display techniques, (vi) Atherosclerosis progression in apolipoprotein E-knockout mice was accelerated by P. gingivalis infection, which was mediated by selective proteolysis of apolipoprotein B-100 by Arg-gingipain (Rgp), (vii) A risk for preterm birth and fetal death in pregnant mice was enhanced by P. gingivalis infection and inhibited by combination treatment of Rgp and Kgp inhibitors, (iii) A newly developed peptide analogue inhibiting both Rgp and Kgp suppressed most of the pethogenicity of P. gingivalis.