Enhancing effect of tazarotene on the HLA-DR expression of cultured human keratinocytes induced by interferon-gamma

Objective: To investigate the effect of tazarotene on the expression of HLA-DR induced by IFN-γ. Methods: (1) Keratinocytes from normal human skin were cultured in vitro;(2) Tazarotene, IFN-γ and the combination of the two compounds were incubated with the keratinocytes in medium, respectively. The expression of HLA-DR in keratinocytes was determined using immunocytochemistry techniques at 24h after incubation. Results: (1) There was rare expression of HLA-DR in normal human keratinocytes; (2) 10-6mol/L tazarotene failed to induce the expression of HLA-DR in keratinocytes at 24h after incubation; (3) 500 U/ml IFN-γ obviously induced the HLA-DR expression in keratinocytes at 24h after treatment; (4) After 24h, 10-7-10-5 mol/L tazarotene had a significantly enhancing effect on the expression of HLA-DR induced by IFN-γ (P<0.005). Conclusion: Tazarotene up-regulates the expression of HLA-DR in keratinocytes cultured in vitro when combined with IFN-γ . Therefore, the reduction of HLA-DR positive keratinocytes in psoriatic lesions may be attributed to not direct interaction of tazarotene in combination with IFN-γ but other pathways.

Enhancing effect of tazarotene on the HLA-DR expression of cultured human keratinocytes induced by interferon-gamma