Innate immunity plays an important role in psoriasis. The possible role of Toll-like receptors (TLRs) in the activation of innate immunity in psoriasis remains unknown. Serum antikeratin 16 (anti-K16) autoantibody levels are raised in patients with psoriasis. The aim of this study was to investigate the effects of anti-K16 antibodies on TLR2 and TLR4 expression in keratinocytes. Keratinocytes were incubated with mouse anti-K16 monoclonal antibodies. Levels of TLR2 and TLR4 were measured by quantitative real-time PCR and flow cytometry. TLR2 mRNA level was increased by 1.73-fold, 1.60-fold and 2.52-fold at 6, 24 and 36 h after incubation, respectively. TLR4 mRNA level was increased by 3.62-fold and 2.21-fold at 12 and 36 h, respectively. TLR2 protein expression was increased by 1.73-fold on the cell membrane and 2.22-fold in cell membrane and intracytoplasmic locations. There was no change in TLR4. The results of this study indicate that anti-K16 antibodies may be a modulator of TLRs.

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