Philips Institute of Oral and Craniofacial Molecular Biology, School of Dentistry, Virginia Commonwealth University, Richmond, VA 23298-0566, USA.
Infect Immun. 2010 Jun;78(6):2385-96. doi: 10.1128/IAI.00510-09. Epub 2010 Mar 22.
The oral bacterium Prevotella intermedia attaches to and invades gingival epithelial cells, fibroblasts, and endothelial cells. Several genes encoding proteins that mediate both the adhesion and invasion processes are carried on the genome of this bacterium. Here, we characterized one such protein, AdpC, belonging to the leucine-rich repeat (LRR) protein family. Bioinformatics analysis revealed that this protein shares similarity with the Treponema pallidum LRR (LRR(TP)) family of proteins and contains six LRRs. Despite the absence of a signal peptide, this protein is localized on the bacterial outer membrane, indicating that it is transported through an atypical secretion mechanism. The recombinant form of this protein (rAdpC) was shown to bind fibrinogen. In addition, the heterologous host strain Escherichia coli BL21 expressing rAdpC (V2846) invaded fibroblast NIH 3T3 cells at a 40-fold-higher frequency than control E. coli BL21 cells expressing a sham P. intermedia 17 protein. Although similar results were obtained by using human umbilical vein endothelial cells (HUVECs), only a 3-fold-increased invasion of V2846 into oral epithelial HN4 cells was observed. Thus, AdpC-mediated invasion is cell specific. This work demonstrated that AdpC is an important invasin protein of P. intermedia 17.
口腔细菌中间普氏菌附着并侵入牙龈上皮细胞、成纤维细胞和内皮细胞。介导粘附和入侵过程的几个基因编码蛋白存在于该细菌的基因组中。在这里，我们对一种属于亮氨酸丰富重复（LRR）蛋白家族的蛋白 AdpC 进行了特征描述。生物信息学分析表明，该蛋白与梅毒密螺旋体 LRR（LRR（TP））家族的蛋白具有相似性，包含六个 LRR。尽管没有信号肽，但该蛋白定位于细菌外膜上，表明它通过非典型的分泌机制进行运输。该蛋白的重组形式（rAdpC）被证明与纤维蛋白原结合。此外，表达 rAdpC 的异源宿主菌株大肠杆菌 BL21（V2846）侵入成纤维细胞 NIH 3T3 的频率比表达虚假中间普氏菌 17 蛋白的对照大肠杆菌 BL21 细胞高 40 倍。尽管用人脐静脉内皮细胞（HUVEC）得到了类似的结果，但仅观察到 V2846 对口腔上皮 HN4 细胞的侵袭增加了 3 倍。因此，AdpC 介导的入侵具有细胞特异性。这项工作表明 AdpC 是中间普氏菌 17 的一种重要入侵蛋白。
