RT Journal Article SR Electronic T1 Inhibition of A. fumigatus growth by human respiratory cells JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P3415 VO 40 IS Suppl 56 A1 Viviane Balloy A1 Jean-Paul Latgé A1 Michel Chignard YR 2012 UL http://erj.ersjournals.com/content/40/Suppl_56/P3415.abstract AB The innate immune response to fungi mainly involves macrophages and neutrophils. By contrast, the possible participation of respiratory epithelial cells (REC) has been poorly studied. In the present study we observed that REC display the property of inhibiting mycelium development of Aspergillus fumigatus (A.f) and that this activity is linked to PI3 kinase activation.Bronchial cells (BEAS-2B cell line) were incubated with A.f and the growth of the fungus was estimated by optical microscopy observation and measurement of galactomannan concentrations in the extracellular media. The role of PI3 kinase was evidenced by the use of the specific inhibitor LY294002 (30 µM). Spore internalization in REC was followed by epifluorescence. FITC-labeled spores (green) when outside of cells were further labelled with an anti-FITC antibody labeled with a red fluorochrome (Alexafluor 568).In the presence of REC, most of the spores do not germinate as opposed to spores incubated in the absence of cells. The growth quantification by galactomamann concentration measurements display a 4.5 lower concentration in the presence of cells. The anti-aspergillus activity is inhibited when cells are incubated with LY294002, indicating the involvement of the PI3 kinase pathway. Of note, inhibitors of p38 MAP kinase and ERK1/2 are inactive. We evidenced that the activity is directed against the spores and not again the hyphae but is not linked to the spore internalization.In conclusion, as macrophages and neutrophils, REC play a role in the anti-aspergillus activity. They are able to prevent the mycelium development and as such potentially prevent its dissemination.Funding: Work supported in part by a grant from Vaincre la Mucoviscidose.