Role of glycogen synthase kinase 3 (GSK-3) in innate immune response of human immature dendritic cells to Aspergillus fumigatus.

Dysregulation of the Th1/Th2 cytokine balance and a switch to a Th2 immune response contribute to the development of and the unfavorable outcome from invasive aspergillosis (IA). We explore in this paper the role of glycogen synthase kinase 3 (GSK-3) in human immature dendritic cells (iDCs) relative to infection caused by A. fumigatus by the use of GSK-3 inhibitors (LiCl, SB415286) and RNA interference technology. In iDCs exposed to A. fumigatus germ tubes, inhibition of GSK-3 with LiCl or SB415286, as well as transfection with small interfering RNA, led to markedly elevated expression of the anti-inflammatory cytokine IL-10. In contrast, pro-inflammatory cytokine response was only partially regulated by GSK-3. Screening of patients after allogeneic stem cell transplantation (with or without IA) for the presence of genetic markers (rs334558, rs6438552) in the GSK-3 gene revealed no significant association with an increased risk for IA. In conclusion, GSK-3 might be involved in the regulation of the anti-inflammatory response of iDCs in the context of infections due to A. fumigatus, albeit the exact mechanisms have to be clarified in future experiments.