IL-17 promotes the conversion of normal neutrophils to PMN-I, an immunostimulating subset of neutrophils (34.14)

Abstract

Abstract Neutrophils (PMN) influenced by Th1 cytokines or Th17 pathway are essential effector cells in host’s anti-Candida resistance. However, the properties of PMN influenced by IL-17 remain unclear. IL-17 is a cytokine produced by Th17 cells. In this paper, PMN-I with the abilities to kill Candida albicans were shown to be generated from normal neutrophils (PMN-N) after stimulation with IL-17. PMN were considered to be PMN-I when resident Mϕ or naive T cells transwell-cultured with PMN samples were converted to M1Mϕ (CCL3+ IL-10- Mϕ) or Th1 cells (IFN-γ+ IL-4- T cells). PMN (1 × 105 cells/ml), isolated from peripheral blood of healthy donors, were cultured with rIL-17 (0.1 to10 ng/ml) for 9 h. Thereafter, these PMN were transwell-cultured for 9 h with resident Mϕ or T cells syngeneic to PMN donors (1 × 106 cells/ml, lower chamber). Cells in the lower chamber were re-cultured for 24 to 48 h, and culture fluids obtained were assayed for M1Mϕ markers (CCL3 and IL-10) or Th1 cell markers (IFN-γ and IL-4) by ELISA. In the results, M1Mϕ were generated from resident Mϕ transwell-cultured with IL-17-stimulated PMN. Also, Th1 cells were generated from naive T cells transwell-cultured with IL-17-stimulated PMN. These results indicate that IL-17 stimulates the neutrophil conversion from PMN-N to PMN-I.