dsRNA-mediated innate immunity of epidermal keratinocytes

M Tohyama, X Dai, K Sayama, K Yamasaki… - Biochemical and …, 2005 - Elsevier
M Tohyama, X Dai, K Sayama, K Yamasaki, Y Shirakata, Y Hanakawa, S Tokumaru…
Biochemical and biophysical research communications, 2005Elsevier
MIP-1α, a CC chemokine, recruits monocytes, natural killer cells, lymphocytes, and
neutrophils, and plays a critical role in viral infection. Since, the lesional epidermis of herpes
zoster expressed MIP-1α, we hypothesized that keratinocytes produce MIP-1α in response
to virus-associated dsRNA via TLR3. To investigate this, we examined cultured human
keratinocytes for MIP-1α production induced by poly (I: C), a TLR3 ligand. Poly (I: C)
treatment induced MIP-1α production, interestingly, poly (I: C)-induced IFN-α and-β …
MIP-1α, a CC chemokine, recruits monocytes, natural killer cells, lymphocytes, and neutrophils, and plays a critical role in viral infection. Since, the lesional epidermis of herpes zoster expressed MIP-1α, we hypothesized that keratinocytes produce MIP-1α in response to virus-associated dsRNA via TLR3. To investigate this, we examined cultured human keratinocytes for MIP-1α production induced by poly(I:C), a TLR3 ligand. Poly(I:C) treatment induced MIP-1α production, interestingly, poly(I:C)-induced IFN-α and -β production preceded MIP-1α production. A neutralizing antibody for IFN-β significantly inhibited the poly(I:C)-induced MIP-1α production indicating that MIP-1α production is via IFN-β. IFN-α priming enhanced TLR3 expression and MIP-1α production in poly(I:C)-treated keratinocytes. This suggests that IFN-α enhanced the TLR3 expression and reinforced the response of keratinocytes to poly(I:C), which resulted in an increase in MIP-1α production. In conclusion, normal human keratinocytes produce MIP-1α in response to dsRNA via TLR3, and this production is regulated by IFN-α/β.
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