Altered function of murine mast cells in response to lipopolysaccharide and peptidoglycan.
Toll-like receptors (TLRs) recognize and signal the presence of bacterial components such as lipopolysaccharide (LPS) and peptidoglycan (PG) as a part of innate immunity. Our previous studies revealed that mast cells function as effector cells in the protection of mice against lethal enterobacterial infections. In this study, we examined both the gene expression of molecules involved in TLR signaling and the effects of LPS and PG in bone marrow-derived cultured mast cells (BMCMCs). The mRNA expression of TLR2, TLR4 and TLR6 was detected in BMCMCs. CD14, MD-2 and MyD88, which are also involved in TLR pathway, were also expressed. Neither LPS nor PG affected degranulation in BMCMCs, but release of tumor necrosis factor increased slightly in response to LPS and PG. Both LPS and PG enhanced expression of pro-matrix metalloproteinase 9 (pro-MMP-9) in a dose-dependent manner, and DNA fragmentation was induced by LPS, but not by PG. These results suggest that mast cells are the targets of LPS and PG, and that the functions of these molecules produced exclusively by bacteria partly overlap, but are distinct.
Ikeda
Teruo
T
Research Institute of Biosciences, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan. ikedat@azabu.u.ac.jp
Funaba
Masayuki
M
D000818:Animals; D015550:Cell Degranulation; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D053938:DNA Fragmentation; D015870:Gene Expression; D018950:Lipopolysaccharide Receptors / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology*; D008407:Mast Cells / Q000502:physiology*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010457:Peptidoglycan / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051216:Toll-Like Receptor 6; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D010457:Peptidoglycan; D011956:Receptors, Cell Surface; C495369:Tlr6 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051216:Toll-Like Receptor 6; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9