Mitsui-Yamaguchi T, Abe A, Danbara H, Kawahara K
Department of Bacteriology, Kitasato Institute, Tokyo, Japan.
Microb Pathog. 1997 Jan;22(1):59-66. doi: 10.1006/mpat.1996.0091.
TNF-alpha mRNA induction in murine macrophages by virulent and avirulent Salmonella strains was measured in vitro by RT-PCR method. Virulence plasmid-cured strains of S. choleraesuis serovar Typhimurium and serovar Choleraesuis, and rpoS-defective mutant of S. choleraesuis serovar Typhimurium induced significantly higher level of TNF-alpha mRNA than their parent (virulent) strains in macrophages of C3H/HeN mice. When macrophages of LPS-low responder (C3H/HeJ) mice were used, the difference of the induction level was not observed, indicating that LPS was involved in the enhanced level of TNF-alpha mRNA induction by avirulent Salmonella strains. LPSs from virulent and avirulent strains were analysed, but no difference was found for cytokine-inducing activity, and chemical properties. Those results suggested that avirulent Salmonella strains were damaged more easily, and released more LPS in macrophages to enhance TNF-alpha induction.
采用逆转录-聚合酶链反应（RT-PCR）法在体外测定了强毒和无毒沙门氏菌菌株对小鼠巨噬细胞中肿瘤坏死因子-α（TNF-α）mRNA的诱导作用。猪霍乱沙门氏菌鼠伤寒血清型和猪霍乱血清型的毒力质粒缺失菌株，以及猪霍乱沙门氏菌鼠伤寒血清型的rpoS缺陷突变体，在C3H/HeN小鼠的巨噬细胞中诱导的TNF-α mRNA水平明显高于其亲本（强毒）菌株。当使用LPS低反应性（C3H/HeJ）小鼠的巨噬细胞时，未观察到诱导水平的差异，这表明LPS参与了无毒沙门氏菌菌株增强的TNF-α mRNA诱导水平。对强毒和无毒菌株的LPS进行了分析，但在细胞因子诱导活性和化学性质方面未发现差异。这些结果表明，无毒沙门氏菌菌株更容易受损，并在巨噬细胞中释放更多的LPS以增强TNF-α的诱导。
