Saturated fatty acid activates but polyunsaturated fatty acid inhibits Toll-like receptor 2 dimerized with Toll-like receptor 6 or 1
AuthorsLee, Joo Y.
Youn, Hyung S.
Weatherill, Amy R.
Lee, Won H.
Fitzgerald, Katherine A.
Hwang, Daniel H.
UMass Chan AffiliationsDepartment of Medicine, Division of Infectious Diseases and Immunology
Document TypeJournal Article
Fatty Acids, Unsaturated
Mice, Inbred C3H
Nitric Oxide Synthase
Nitric Oxide Synthase Type II
Receptors, Cell Surface
Reverse Transcriptase Polymerase Chain Reaction
Toll-Like Receptor 1
Toll-Like Receptor 2
Toll-Like Receptor 4
Toll-Like Receptor 6
Immunology and Infectious Disease
MetadataShow full item record
AbstractToll-like receptor 4 (TLR4) and TLR2 agonists from bacterial origin require acylated saturated fatty acids in their molecules. Previously, we reported that TLR4 activation is reciprocally modulated by saturated and polyunsaturated fatty acids in macrophages. However, it is not known whether fatty acids can modulate the activation of TLR2 or other TLRs for which respective ligands do not require acylated fatty acids. A saturated fatty acid, lauric acid, induced NFkappaB activation when TLR2 was co-transfected with TLR1 or TLR6 in 293T cells, but not when TLR1, 2, 3, 5, 6, or 9 was transfected individually. An n-3 polyunsaturated fatty acid (docosahexaenoic acid (DHA)) suppressed NFkappaB activation and cyclooxygenase-2 expression induced by the agonist for TLR2, 3, 4, 5, or 9 in a macrophage cell line (RAW264.7). Because dimerization is considered one of the potential mechanisms for the activation of TLR2 and TLR4, we determined whether the fatty acids modulate the dimerization. However, neither lauric acid nor DHA affected the heterodimerization of TLR2 with TLR6 as well as the homodimerization of TLR4 as determined by co-immunoprecipitation assays in 293T cells in which these TLRs were transiently overexpressed. Together, these results demonstrate that lauric acid activates TLR2 dimers as well as TLR4 for which respective bacterial agonists require acylated fatty acids, whereas DHA inhibits the activation of all TLRs tested. Thus, responsiveness of different cell types and tissues to saturated fatty acids would depend on the expression of TLR4 or TLR2 with either TLR1 or TLR6. These results also suggest that inflammatory responses induced by the activation of TLRs can be differentially modulated by types of dietary fatty acids.
SourceJ Biol Chem. 2004 Apr 23;279(17):16971-9. Epub 2004 Feb 13. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/35259
Related ResourcesLink to Article in PubMed
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