The Role of PdpC in determination of the virulence of Francisella tularensis

利用pdpC基因敲除和互补菌株检测了致病决定蛋白C(PdpC)在确定图拉氏方济氏菌毒力中的作用。这些数据表明，PdpC是决定图拉氏丝孢子菌致病力的重要元件。尤其是PdpC分子的1303、1309和1324位氨基酸的三个C末端赖氨酸残基是致病所必需的。用抗PdpC抗体免疫共沉淀法测定接种土拉弗氏菌的巨噬细胞裂解产物与乳杆菌PdpC的相互作用分子。这些数据表明，弗朗西斯拉PdpC分子将与核酸结合。此外，基因芯片分析表明，接种土拉氏新城疫杆菌强毒株的巨噬细胞中的新城疫杆菌PdpC分子可以抑制该基因的表达，从而消灭胞内细菌。

Role of pathogenicity determinant protein C (PdpC) in determining the virulence of the Francisella tularensis was examined using the pdpC knockout and the complemented strains. These data showed that PdpC was an essential element determining F. tularensis pathogenicity. Especially, three C-terminal lysine residues at amino acid positions 1303, 1309 and 1324 of PdpC molecule were indispensable for the pathogenicity. The lysates of macrophages inoculated with F. tularensis were immunoprecipitated with anti-PdpC antibody to determine the interactive molecules with Franicsella PdpC. The data indicated that Francisella PdpC molecule would bind to nucleic acid. In addition, it was suggested that Francisella PdpC molecule in the macrophages inoculated with virulent Francisella tularensis strain could suppress the gene expression to eliminate the intracellular bacteria by microarray analysis.