Innate immune surveillance in the blood is executed mostly by circulating monocytes, which recognise conserved bacterial molecules such as peptidoglycan and lipopolysaccharide. Toll-like receptors (TLR) play a central role in microbe-associated molecular pattern detection. Here, we compared the differences in TLR expression and cytokine production after stimulation of peripheral blood cells with heat-killed Gram-negative and Gram-positive human pathogens Neisseria meningitidis, Escherichia coli, Staphylococcus aureus and Streptococcus pneumoniae. We found that TLR2 expression is up-regulated on monocytes after stimulation with S. aureus, S. pneumoniae, E. coli and N. meningitidis. Moreover, TLR2 up-regulation was positively associated with increasing concentrations of Gram-positive bacteria, whereas higher concentrations of Gram-negative bacteria, especially E. coli, caused a milder TLR2 expression increase compared with low doses. Cytokines were produced in similar dose-dependent profiles regardless of the stimulatory pathogen; however, Gram-negative pathogens induced higher cytokine levels than Gram-positive ones at same concentrations. These results indicate that Gram-positive and Gram-negative bacteria differ in their dose-dependent patterns of induction of TLR2 and TLR4, but not in cytokine expression.

• MeSH
• aktivace transkripce MeSH
• cytokiny biosyntéza   MeSH
• gramnegativní bakterie genetika   imunologie   MeSH
• grampozitivní bakterie genetika   imunologie   MeSH
• lidé MeSH
• monocyty imunologie   MeSH
• přirozená imunita MeSH
• regulace genové exprese MeSH
• signální transdukce imunologie   MeSH
• toll-like receptor 2 biosyntéza   genetika   imunologie   MeSH
• toll-like receptor 4 biosyntéza   genetika   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH