Role of autophagy in regulating the immune response of dendritic cells to Talaromyces marneffei infection.

Autophagy can regulate antimicrobial immunity. However, it is unknown whether autophagy mediates the immune response of dendritic cells (DCs) to Talaromyces marneffei (T. marneffei) infection. Therefore, to explore the relationship between autophagy and multiplication of T. marneffei and investigate whether ERK1/2 signaling pathway regulates activation of autophagy and TNF-α and IFN-γ secretion by intracellular signaling mechanisms during T. marneffei infection in human DCs. DCs were infected with T. marneffei for different times. First, we found that T. marneffei induced activation of autophagy and ERK1/2 in human DCs. Second, the inhibition of ERK1/2 suppressed activation of autophagy in T. marneffei-infected human DCs. Third, the suppression of ERK1/2 and autophagy decreased TNF-α and IFN-γ production and increased the proliferation of T. marneffei. These data suggest that ERK pathway plays vital regulatory roles in activation of autophagy and subsequent cytokine production during T. marneffei infection. Our data further indicate that autophagy is important in the regulation of the DC immune response to T. marneffei infection, thereby extending our understanding of host immune responses to the fungus.