绵羊支原体肺炎是由绵羊肺炎支原体(MO)感染引起的一种世界性的传染病，严重危害着我国养羊业的健康发展。由于目前对绵羊肺炎支原体的毒力因子研究不够充分，导致对该菌致病的分子机理和有效防治措施的研究严重滞后。为此，本项目拟对MO模式株Y98菌体荚膜多糖的组成与结构进行初步分析，利用滩羊支气管上皮细胞气液相培养模型、原代肺泡巨噬细胞和小鼠肺脏体内模型研究该菌荚膜多糖粘附宿主细胞和定居呼吸道上皮的作用，进而对上皮细胞和肺泡巨噬细胞在抗MO感染过程中的免疫学反应和细胞氧化损伤等生物学作用机制进行研究，以期进一步揭示绵羊肺炎支原体荚膜多糖的结构与功能、宿主-病原相互作用关系、以及绵羊肺炎支原体的致病机理。

The emergence of sheep pneumonia caused by the infection of Mycoplasma ovipneumoniae (MO) has significantly hampered sheep industry countrywide in China. A poor understanding in the pathogenic factors of MO has led the difficulty for us to understand the molecular mechanism of the pathogenesis of MO, and design an effective measure for the prevention and treatment against MO infection. Thus, in addition to a primary exploration of the compositions and structures of capsular polysaccharides (CPS) of the reference strain MO Y98, the proposal mainly intends to interrogate the biological functions of CPS of MO on the microbial adhesion and colonization of host cells, as well as the immunological responses and oxidative injury induced by MO on the pulmonary epithelial cells and macrophage of Tan sheep using a novel air-liquid interface pulmonary epithelial model that generated from bronchial epithelial cells of Ningxia Tan sheep. This study will allows us to better understand the components, chemistry structures and biological properties of CPS of MO, which will also offer useful information and foundation for uncovering the host-pathogen interaction, as well as the molecular mechanism of pathogenesis of MO.