PDF(Pubmed)
Abstract：
Mesomycoplasma hyopneumoniae is the etiological agent of mycoplasmal pneumonia of swine (MPS), which causes substantial economic losses to the world\'s swine industry. Moonlighting proteins are increasingly being shown to play a role in the pathogenic process of M. hyopneumoniae. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme in glycolysis, displayed a higher abundance in a highly virulent strain of M. hyopneumoniae than in an attenuated strain, suggesting that it may have a role in virulence. The mechanism by which GAPDH exerts its function was explored. Flow cytometry and colony blot analysis showed that GAPDH was partly displayed on the surface of M. hyopneumoniae. Recombinant GAPDH (rGAPDH) was able to bind PK15 cells, while the adherence of a mycoplasma strain to PK15 was significantly blocked by anti-rGAPDH antibody pretreatment. In addition, rGAPDH could interact with plasminogen. The rGAPDH-bound plasminogen was demonstrated to be activated to plasmin, as proven by using a chromogenic substrate, and to further degrade the extracellular matrix (ECM). The critical site for GAPDH binding to plasminogen was K336, as demonstrated by amino acid mutation. The affinity of plasminogen for the rGAPDH C-terminal mutant (K336A) was significantly decreased according to surface plasmon resonance analysis. Collectively, our data suggested that GAPDH might be an important virulence factor that facilitates the dissemination of M. hyopneumoniae by hijacking host plasminogen to degrade the tissue ECM barrier. IMPORTANCE Mesomycoplasma hyopneumoniae is a specific pathogen of pigs that is the etiological agent of mycoplasmal pneumonia of swine (MPS), which is responsible for substantial economic losses to the swine industry worldwide. The pathogenicity mechanism and possible particular virulence determinants of M. hyopneumoniae are not yet completely elucidated. Our data suggest that GAPDH might be an important virulence factor in M. hyopneumoniae that facilitates the dissemination of M. hyopneumoniae by hijacking host plasminogen to degrade the extracellular matrix (ECM) barrier. These findings will provide theoretical support and new ideas for the research and development of live-attenuated or subunit vaccines against M. hyopneumoniae.
摘要：
猪肺炎支原体是猪支原体肺炎（MPS）的病原体，这给世界养猪业造成了巨大的经济损失。月光蛋白越来越多地显示在猪肺炎支原体的致病过程中起作用。甘油醛-3-磷酸脱氢酶(GAPDH),糖酵解的关键酶，猪肺炎支原体高毒力菌株的丰度高于减毒株，表明它可能在毒力中起作用。探讨了GAPDH发挥其功能的机制。流式细胞术和菌落印迹分析显示GAPDH部分显示在猪肺炎支原体表面。重组GAPDH(rGAPDH)能够结合PK15细胞,而抗rGAPDH抗体预处理显着阻断了支原体菌株对PK15的粘附。此外,rGAPDH可与纤溶酶原相互作用。证明rGAPDH结合的纤溶酶原被激活为纤溶酶，通过使用显色底物证明，进一步降解细胞外基质(ECM)。GAPDH与纤溶酶原结合的关键位点是K336,如通过氨基酸突变所证明的。根据表面等离子体共振分析，纤溶酶原对rGAPDHC末端突变体（K336A）的亲和力显着降低。总的来说，我们的数据表明,GAPDH可能是一种重要的毒力因子,通过劫持宿主纤溶酶原来降解组织ECM屏障,从而促进猪肺炎支原体的传播.重要性猪肺炎支原体是猪的一种特殊病原体，是猪支原体肺炎（MPS）的病原体，这对全球养猪业造成了巨大的经济损失。猪肺炎支原体的致病机制和可能的特定毒力决定因素尚未完全阐明。我们的数据表明，GAPDH可能是猪肺炎支原体的重要毒力因子，通过劫持宿主纤溶酶原降解细胞外基质（ECM）屏障来促进猪肺炎支原体的传播。这些发现将为猪肺炎支原体减毒活疫苗或亚单位疫苗的研发提供理论支持和新思路。
