Tanaka H, Sagisaka A, Fujita K, Kaneko Y, Imanishi S, Yamakawa M
Innate Immunity Research Unit, National Institute of Agrobiological Sciences, Ibaraki, Japan.
Insect Mol Biol. 2009 Feb;18(1):71-5. doi: 10.1111/j.1365-2583.2009.00851.x.
Lipopolysaccharide (LPS), a major cell wall component of gram-negative bacteria, was found to be unable to activate immune-related genes in Drosophila melanogaster. In contrast, highly purified LPS elicited immune-related gene expression in the fat body of Bombyx mori. However, the level of activation by highly purified LPS was lower than crude LPS and peptidoglycan. Furthermore, synthetic lipid A also activated these genes, suggesting that B. mori possesses unknown signal pathways to activate immune-related genes by LPS. Up-regulation of antimicrobial peptide genes by highly purified LPS was not confirmed in the immune-responsive cell line, NIAS-Bm-aff3, suggesting that some factors necessary for signal transduction activated by LPS are deficient in this cell line.
脂多糖（LPS）是革兰氏阴性菌细胞壁的主要成分，研究发现其无法激活黑腹果蝇中的免疫相关基因。相比之下，高度纯化的LPS能引发家蚕脂肪体中免疫相关基因的表达。然而，高度纯化的LPS的激活水平低于粗制LPS和肽聚糖。此外，合成脂质A也能激活这些基因，这表明家蚕拥有未知的信号通路，可通过LPS激活免疫相关基因。在免疫反应细胞系NIAS-Bm-aff3中，未证实高度纯化的LPS能上调抗菌肽基因，这表明该细胞系缺乏LPS激活信号转导所需的某些因子。
