Wareth Gamal, Melzer Falk, Weise Christoph, Neubauer Heinrich, Roesler Uwe, Murugaiyan Jayaseelan
Institute of Animal Hygiene and Environmental Health, Centre for Infectious Medicine, Freie Universität Berlin, Germany; Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
Biochem Biophys Res Commun. 2015 Jan 2;456(1):202-6. doi: 10.1016/j.bbrc.2014.11.059. Epub 2014 Nov 22.
Brucella (B.) species lack classical virulence factors, but escape effectively the immune response of the host. The species Brucella abortus and Brucella melitensis infect predominantly cattle and small ruminants such as sheep or goats, respectively, but account also for most human cases. These two species share remarkably similar genomes but different proteomes have been demonstrated. This might be one of the reasons for their host specificity. A comprehensive identification of immunodominant proteins of these two species using antibodies present in the serum of naturally infected ruminants might provide insight on the mechanism of their infection in different hosts. In the present study, whole-cell protein extracts of B. abortus and B. melitensis were separated using SDS-PAGE and western blotting was performed using field sera from cows, buffaloes, sheep and goats. Protein bands that matched with western blot signals were excised, digested with trypsin and subjected to protein identification using MALDI-TOF MS. Identified proteins included heat shock proteins, enzymes, binding proteins and hypothetical proteins. Antibodies against the same set of antigen were found for all species investigated, except for superoxide dismutase of B. melitensis for which antibodies were demonstrated only in sheep serum. Brucellae appear to express these proteins mainly for their survival in the host system during infection.
布鲁氏菌属缺乏典型的毒力因子，但能有效逃避宿主的免疫反应。流产布鲁氏菌和马尔他布鲁氏菌分别主要感染牛和绵羊或山羊等小型反刍动物，但也是大多数人类病例的病因。这两个物种的基因组非常相似，但已证明其蛋白质组不同。这可能是它们宿主特异性的原因之一。利用自然感染反刍动物血清中的抗体全面鉴定这两个物种的免疫显性蛋白，可能有助于深入了解它们在不同宿主中的感染机制。在本研究中，使用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分离流产布鲁氏菌和马尔他布鲁氏菌的全细胞蛋白提取物，并用来自奶牛、水牛、绵羊和山羊的现场血清进行蛋白质印迹分析。切下与蛋白质印迹信号匹配的蛋白条带，用胰蛋白酶消化，然后使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）进行蛋白质鉴定。鉴定出的蛋白质包括热休克蛋白、酶、结合蛋白和假定蛋白。在所研究的所有物种中都发现了针对同一组抗原的抗体，但马尔他布鲁氏菌的超氧化物歧化酶除外，仅在绵羊血清中检测到针对该酶的抗体。布鲁氏菌似乎主要在感染期间表达这些蛋白质以在宿主系统中存活。
