First Author | Shindou H | Year | 2005 |
Journal | J Immunol | Volume | 175 |
Issue | 2 | Pages | 1177-83 |
PubMed ID | 16002720 | Mgi Jnum | J:100729 |
Mgi Id | MGI:3589348 | Doi | 10.4049/jimmunol.175.2.1177 |
Citation | Shindou H, et al. (2005) Priming effect of lipopolysaccharide on acetyl-coenzyme A:lyso-platelet-activating factor acetyltransferase is MyD88 and TRIF independent. J Immunol 175(2):1177-83 |
abstractText | LPS has a priming effect on various stimuli. For instance, LPS priming enhances the production of platelet-activating factor (PAF), a proinflammatory lipid mediator that is induced by PAF itself. Among various enzymes responsible for PAF biosynthesis, acetyl-coenzyme A:1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine acetyltransferase is one of the enzymes activated by PAF receptor stimulation. In this study we investigated the priming effect of LPS on the acetyltransferase activation by PAF in TLR4-knockout (KO) mice, MyD88-KO mice, and Toll/IL-1R domain-containing adaptor inducing IFN-beta (TRIF)-KO mice. This enzyme was biphasically activated by LPS. Although the first peak occurred within 30 min in wild-type (WT), but not TLR4-KO or MyD88-KO, macrophages, the second phase reached a maximum within hours in WT, MyD88-KO, and TRIF-KO, but not in TLR4-KO, macrophages. Only in the second phase was the increase in acetyltransferase activity upon PAF receptor activation remarkably enhanced in WT, MyD88-KO, and TRIF-KO cells, but not in TLR4-KO cells. These data demonstrated that LPS exerted a priming effect on PAF receptor-mediated acetyltransferase activation through the TLR4-dependent, but MyD88- and TRIF-independent, pathway. |