Toll-Like Receptors Required for Dermatophagoides farinae to Activate NF-kappa B

作者：Kitajima Takaaki; Muroi Masashi^*; Yamashita Naomi; Tanamoto Ken ichi

来源：Biological & Pharmaceutical Bulletin, 2014, 37(1): 74-80.

DOI：10.1248/bpb.b13-00595

• house dust mite
• allergen
• innate immunity

Body and excrement extracts from Dermatophagoides Prime were used to study stimulation of Toll-like receptors (TLRs). The excrement extract stimulated nuclear factor (NF)-kappa B-dependent reporter activity to an extent similar to lipopolysaccharide (LPS) in a mouse macrophage cell line, J774A.1, but the activity of the body extract was negligible. The excrement extract also activated NF-kappa B in HEK293 cells expressing TLR1/TLR2, TLR2/TLR6 and CD14/TLR4/MD-2, whereas no activation was observed in cells expressing TLR3, TLR5, TLR7, TLR8 or TLR9. Although the excrement extract required co-expression of CD14, TLR4 and MD-2 in HEK293 cells to activate NF-kappa B, efficient activation was still observed in I-13.35 cells, a bone-marrow macrophage cell line established from LPS-hypo-responsive C3H/HeJ mice. The excrement extract activated NF-kappa B in HEK293 cells expressing TLR2 alone, but the activation was significantly increased by co-expression of CD14. Polymyxin B inhibited CD14/TLR4/MD-2- and CD14/TLR2-mediated activation of NF-kappa B but not the activation in I-13.35 cells. These results indicate that CD14/TLR4/MD-2-dependent and CD14/TLR2-dependent mechanisms are involved in the activation of NF-kappa B by the excrement extract of D. farinae and suggest that the extract also contains substances that activate NF-kappa B through non-TLR-mediated mechanisms.

• 出版日期2014-1