Gene Expressions of Toll-Like Receptor 2, But Not Toll-Like Receptor 4, Is Induced by LPS and Inflammatory Cytokines in Mouse Macrophages
| Autor: | Yasunobu Yoshikai, Tipayaratn Musikacharoen, Tomohiko Ogawa, Tetsuya Matsuguchi |
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| Rok vydání: | 2000 |
| Předmět: |
Lipopolysaccharides
Immunology Receptors Cell Surface Biology p38 Mitogen-Activated Protein Kinases Cell Line Proinflammatory cytokine Lipid A Mice Gene expression Animals Drosophila Proteins Immunology and Allergy RNA Messenger Receptor Mice Inbred BALB C Mice Inbred C3H Toll-like receptor Membrane Glycoproteins Innate immune system Macrophages Toll-Like Receptors NF-kappa B Molecular biology Toll-Like Receptor 2 Up-Regulation Cell biology Toll-Like Receptor 4 TLR2 Gene Expression Regulation TLR4 Cytokines lipids (amino acids peptides and proteins) Inflammation Mediators Mitogen-Activated Protein Kinases Signal Transduction |
| Zdroj: | The Journal of Immunology. 165:5767-5772 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Toll-like receptors (TLRs) are a family of mammalian homologues of Drosophila Toll and play important roles in host defense. Two of the TLRs, TLR2 and TLR4, mediate the responsiveness to LPS. Here the gene expression of TLR2 and TLR4 was analyzed in mouse macrophages. Mouse splenic macrophages responded to an intraperitoneal injection or in vitro treatment of LPS by increased gene expression of TLR2, but not TLR4. Treatment of a mouse macrophage cell line with LPS, synthetic lipid A, IL-2, IL-15, IL-1β, IFN-γ, or TNF-α significantly increased TLR2 mRNA expression, whereas TLR4 mRNA expression remained constant. TLR2 mRNA increase in response to synthetic lipid A was severely impaired in splenic macrophages isolated from TLR4-mutated C3H/HeJ mice, suggesting that TLR4 plays an essential role in the process. Specific inhibitors of mitogen-activated protein/extracellular signal-regulated kinase kinase and p38 kinase did not significantly inhibit TLR2 mRNA up-regulation by LPS. In contrast, LPS-mediated TLR2 mRNA induction was abrogated by pretreatment with a high concentration of curcumin, suggesting that NF-κB activation may be essential for the process. Taken together, our results indicate that TLR2, in contrast to TLR4, can be induced in macrophages in response to bacterial infections and may accelerate the innate immunity against pathogens. |
| Databáze: | OpenAIRE |
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