Department of Microbiology, College of Medicine, Soochow University, Suzhou, Jiangsu Province, 215123, China.
Department of Microbiology, College of Medicine, Soochow University, Suzhou, Jiangsu Province, 215123, China.
Microb Pathog. 2018 Dec;125:183-188. doi: 10.1016/j.micpath.2018.09.017. Epub 2018 Sep 11.
Human granulocytic anaplasmosis (HGA), an increasingly recognized febrile tick-borne illness, is caused by a gram-negative obligate intracellular bacterium Anaplasma phagocytophilum. Because of nonspecific clinical manifestations, diagnosis of HGA highly depends on laboratory tests. Identification of immunoreactive proteins is prerequisite for development of specific and sensitive immunoassays for HGA. In this study, we identified novel immunoreactive proteins of A. phagocytophilum. Previous studies indicated that secreted proteins of A. phagocytophilum and other bacteria can be immunoreactive antigens. Here we in silico screened A. phagocytophilum genome for encoding proteins which bear features of type IV secretion system substrates. Among seventy seven predicted proteins, fourteen proteins were determined for antigenicity and nine proteins were showed to be immunoreactive antigens. In addition, an APH1384 peptide harboring a B cell epitope predicted by bioinformatics was found specifically reacting with anti-A. phagocytophilum sera. Hereby, we identified novel immunoreactive proteins and delineated a specific epitope of A. phagocytophilum, which might be employed for HGA diagnosis.
人粒细胞无形体病（HGA）是一种日益被认识的发热性蜱传疾病，由革兰氏阴性专性细胞内细菌嗜吞噬细胞无形体引起。由于临床表现无特异性，HGA 的诊断高度依赖实验室检测。鉴定免疫反应性蛋白是开发 HGA 特异性和敏感免疫检测方法的前提。在本研究中，我们鉴定了嗜吞噬细胞无形体的新型免疫反应性蛋白。先前的研究表明，嗜吞噬细胞无形体和其他细菌的分泌蛋白可以作为免疫反应性抗原。在此，我们通过计算机筛选了嗜吞噬细胞无形体基因组中编码具有 IV 型分泌系统底物特征的蛋白。在 77 个预测蛋白中，有 14 个蛋白具有抗原性，9 个蛋白表现为免疫反应性抗原。此外，还发现了一个含有生物信息学预测的 B 细胞表位的 APH1384 肽，该肽特异性地与抗嗜吞噬细胞无形体血清反应。因此，我们鉴定了新型免疫反应性蛋白，并描绘了嗜吞噬细胞无形体的一个特异性表位，该表位可能用于 HGA 的诊断。
