Duda Katarzyna Anna, Duda Katarzyna Teresa, Beczała Agnieszka, Kasperkiewicz Katarzyna, Radziejewska-Lebrecht Joanna, Skurnik Mikael
Department of Microbiology, Faculty of Biology and Environment Protection, University of Silesia, Katowice, Poland.
Arch Immunol Ther Exp (Warsz). 2009 Mar-Apr;57(2):147-51. doi: 10.1007/s00005-009-0018-9. Epub 2009 Mar 31.
Bacteria of the genus Proteus are opportunistic pathogens and cause mainly urinary tract infections. They also play a role in the pathogenesis of reactive arthritis (RA). Patients suffering from Yersinia-triggered RA often carry high titers of antibodies specific to enterobacterial common antigen (ECA). The immunogenicity of ECA has not received much attention thus far and studies have focused mainly on the ECA of Escherichia coli and Yersinia enterocolitica. In this paper the ECA-immunogenicity of Proteus mirabilis is elucidated using two wild-type strains (S1959 and O28) as well as their rough (R) derivative strains R110/1959, which expresses lipopolysaccharide (LPS) with a full core, and R4/O28, which expresses LPS with only an inner core.
Rabbit polyclonal antisera were produced by immunization with boiled suspensions of the four P. mirabilis strains. The antisera were tested for the presence of antibodies specific to ECA by Western blotting using glycerophospholipid- linked ECA (ECA(PG)) of Salmonella montevideo as antigen. Lipopolysaccharide (LPS) was isolated from the four strains by the hot phenol/water procedure in which ECA(PG) is co-extracted with LPS and by the phenol/chloroform/petroleum ether extraction that results in the isolation of LPS and/or LPS-linked ECA (ECA(LPS)) free of ECA(PG). The LPS preparations were tested for the presence of ECA by Western blotting using ECA-specific antibodies.
The results demonstrated that all four P. mirabilis strains were ECA immunogenic. The rabbit antisera immunized by the four strains all contained ECA-specific antibodies. Analysis of the LPS preparations demonstrated that the P. mirabilis wild-type strains O28 and S1959 and the Ra mutant strain R110/1959 expressed ECA(LPS), suggesting that it induced the anti-ECA antibody responses. Only the presence of ECA(PG) could be demonstrated in the Rc mutant strain R4/O28.
These results therefore suggest that, similar to E. coli, LPS with a full core is also required as the acceptor of ECA for P. mirabilis strains to produce ECA(LPS). Since ECA(PG) is not immunogenic unless combined with some proteins, it is likely that ECA(PG)-protein complexes formed during the intravenous immunization with the Rc mutant strain R4/O28.
变形杆菌属细菌是机会致病菌，主要引起尿路感染。它们在反应性关节炎（RA）的发病机制中也起作用。患有耶尔森菌引发的RA的患者通常携带高滴度的针对肠杆菌共同抗原（ECA）的特异性抗体。迄今为止，ECA的免疫原性尚未受到太多关注，研究主要集中在大肠杆菌和小肠结肠炎耶尔森菌的ECA上。本文使用两株野生型菌株（S1959和O28）及其粗糙（R）衍生菌株R110/1959（表达具有完整核心的脂多糖（LPS））和R4/O28（仅表达具有内核的LPS）阐明奇异变形杆菌的ECA免疫原性。
用四株奇异变形杆菌菌株的煮沸悬浮液免疫制备兔多克隆抗血清。使用蒙得维的亚沙门氏菌的甘油磷脂连接的ECA（ECA(PG)）作为抗原，通过蛋白质印迹法检测抗血清中ECA特异性抗体的存在。通过热酚/水法从四株菌株中分离脂多糖（LPS），其中ECA(PG)与LPS共提取，以及通过苯酚/氯仿/石油醚提取法，该方法可分离出不含ECA(PG)的LPS和/或与LPS连接的ECA（ECA(LPS)）。使用ECA特异性抗体通过蛋白质印迹法检测LPS制剂中ECA的存在。
结果表明，所有四株奇异变形杆菌菌株均具有ECA免疫原性。用这四株菌株免疫的兔抗血清均含有ECA特异性抗体。对LPS制剂的分析表明，奇异变形杆菌野生型菌株O28和S1959以及Ra突变株R110/1959表达ECA(LPS)，表明其诱导了抗ECA抗体反应。在Rc突变株R4/O28中仅能证明ECA(PG)的存在。
因此，这些结果表明与大肠杆菌类似，奇异变形杆菌菌株产生ECA(LPS)也需要具有完整核心结构的LPS作为ECA的受体。由于ECA(PG)除非与某些蛋白质结合否则不具有免疫原性，因此在用Rc突变株R4/O28进行静脉内免疫期间可能形成了ECA(PG)-蛋白质复合物。
