Objective: To investigate the effects of Trichophyton rubrum exposure on the expressions of toll-like receptor-2 (TLR-2), TLR-4 and dendritic cell associated C-type lectin-1 (Dectin-1) and cytokine secretions in human keratinocytes cell line HaCaT.
Methods: The mRNA of TLR-2,4, and dectin-1 in the HaCaT co-cultured with the conidia of Trichophyton rubrum conidia for 24 h was measured with real-time PCR. The mean fluorescence intensity and the percentage of cells positive for TLR-2, 4, and dectin-1 was detected during the co-culture using flow cytometry. The cytokine secretion profiles in the cell culture supernatant was analyzed using a cytokine antibody array.
Results: The TLR-2,4, and dectin-1 mRNA expressions, mean fluorescence intensity and percentage of positive cells for TLR-2,4, and dectin-1 all increased in HaCaT cells in response to Trichophyton rubrum conidia exposure. The results of cytokine antibody array demonstrated obviously increased secretions of IL-8, I-309, IFN-γ, IL-6, and IL-13 in the culture supernatant of HaCaT cells in response to Trichophyton rubrum exposure.
Conclusion: The immune responses and immunological recognition of human keratinocytes to Trichophyton rubrum conidia are partially mediated by up-regulating the expressions of TLR-2, TLR-4 and dectin-1 and secretions of multiple cytokines.