Verification of elicitor efficacy of lipopolysaccharides and peptidoglycans on antibacterial peptide gene expression in Bombyx mori.
We verified the efficacy of lipopolysaccharide (LPS) in activating the cecropin B gene (CecB) in an immune-competent Bombyx mori cell line. Strong activation of CecB by the LPSs from Escherichia coli, Pseudomonas aeruginosa, and Salmonella minnesota were completely eliminated after digestion of the LPSs with muramidase. The results clearly indicate that a polymer form of PGN in the LPSs elicited CecB. An oligonucleotide microarray screen revealed that none of the 16,000 genes on the array were activated by LPS in the cells. In contrast, E. coli PGN strongly elicited five antibacterial peptide genes and numerous other genes, and PGN from Micrococcus luteus activated only several genes. Semi-quantitative RT-PCR revealed that all antibacterial genes activated by both PGNs, but the extents were 10-100 times higher with E. coli PGN. Similarly, higher elicitor activity of E. coli than M. luteus was indicated using peptidoglycan recognition protein gene, which is involved in pro-phenol oxidase cascade.
Ha Lee
Joon
J
Invertebrate Gene Function Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan.
Hee Lee
In
I
Noda
Hiroaki
H
Mita
Kazuei
K
Taniai
Kiyoko
K
D000818:Animals; D012831:Bombyx / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D010450:Endopeptidases; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006090:Gram-Negative Bacteria / Q000737:chemistry; D006094:Gram-Positive Bacteria / Q000737:chemistry; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis; D010457:Peptidoglycan / Q000494:pharmacology*; D013682:Teichoic Acids / Q000494:pharmacology
D002352:Carrier Proteins; D019476:Insect Proteins; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D013682:Teichoic Acids; C405332:beta-1,3-glucan recognition protein, insect; C118897:peptidoglycan recognition protein; C009900:lipoteichoic acid; C031162:cecropin B protein, Insecta; D010450:Endopeptidases; C021816:mutanolysin