ABSTRACT
Enterococcus faecalis is a resident lactic acid bacterium in the human intestine. Its immunostimulatory action was reported to be enhanced by heat sterilization. To investigate its beneficial actions, we evaluated the ability of 10 E. faecalis strains to induce interleukin-12 (IL-12) production in a mouse macrophage cell line, J774.1 and found that the strain, E. faecalis IC-1, had a potent IL-12-inducing ability. Furthermore, we investigated the underlying mechanism by treating IC-1 cells with RNase or lysozyme. Its activity almost disappeared and an antagonist of Toll-like receptor (TLR) 7 inhibited this activity. Moreover, lysozyme-treated IC-1 bacteria were not phagocytized by J774.1 cells, and did not induce IL-12 production. Based on our results, we propose that macrophages recognize the cell wall components of IC-1, leading to phagocytosis. The IC-1 RNA is then recognized by TLR7, which induces the production of IL-12.
Subject(s)
Cell Wall/immunology , Enterococcus faecalis/immunology , Interleukin-12/immunology , Macrophages/immunology , RNA, Bacterial/immunology , Animals , Cell Line , Cell Wall/chemistry , Cell Wall/drug effects , Coculture Techniques , Enterococcus faecalis/chemistry , Enterococcus faecalis/drug effects , Gene Expression , Interleukin-12/biosynthesis , Macrophages/cytology , Macrophages/drug effects , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/genetics , Membrane Glycoproteins/immunology , Mice , Muramidase/chemistry , Muramidase/pharmacology , Oligonucleotides/pharmacology , Phagocytosis/drug effects , RNA, Bacterial/chemistry , Ribonucleases/chemistry , Ribonucleases/pharmacology , Toll-Like Receptor 7/antagonists & inhibitors , Toll-Like Receptor 7/genetics , Toll-Like Receptor 7/immunologyABSTRACT
Organic molecular semiconductors are solution processable, enabling the growth of large-area single-crystal semiconductors. Improving the performance of organic semiconductor devices by increasing the charge mobility is an ongoing quest, which calls for novel molecular and material design, and improved processing conditions. Here we show a method to increase the charge mobility in organic single-crystal field-effect transistors, by taking advantage of the inherent softness of organic semiconductors. We compress the crystal lattice uniaxially by bending the flexible devices, leading to an improved charge transport. The mobility increases from 9.7 to 16.5 cm(2) V(-1) s(-1) by 70% under 3% strain. In-depth analysis indicates that compressing the crystal structure directly restricts the vibration of the molecules, thus suppresses dynamic disorder, a unique mechanism in organic semiconductors. Since strain can be easily induced during the fabrication process, we expect our method to be exploited to build high-performance organic devices.
