WS17.3 Alteration of human macrophage functions in cystic fibrosis

Abstract

Recently, several reports suggest that CFTR should contribute to altered inflam-matory response in cystic fibrosis (CF) by modification of normal macrophagefunctions. In order to highlight possible intrinsic macrophage defects due to CFTRdysfunction, we have studied macrophages from human peripheral blood monocytesof healthy subjects (non CF) and CF patients.Ficoll isolated adherent monocytes were differentiated in macrophages with GM-CSF (400U/mL) during 6 days. Non CF macrophages were treated during 72h withCFTRinh−172(10, 20mM). We have focused to study some membrane markers ofCD71+macrophages (mCD14, CD16, CD64, CD11b) by flow cytometry. SolubleCD14, IL-1b and IL-8 supernatant levels were quantified by ELISA. Phagocytosiswas measured by fluorescein-labeledE. coliBioparticles.In CF macrophages, we have observed strong inhibition of phagocytosis (70%)as well as 1.3-, 1.8- and 2.0-fold significant decrease of CD16, CD64 andCD11b respectively. However membrane CD14 (mCD14) was slightly increased butmCD14/sCD14 ratio is in favor of sCD14 (1/6vs1/270 in CF cells). Elsewhere,concentrations of IL-1b and IL-8 were strongly raised in CF cell supernatant. CFTRinhibition in non CF macrophages also showed alterations in surface expression ofCD11b, CD16, CD64, IL-8 level and phagocytosis.Pathogens recognition and phagocytosis seems to be impaired in CF macrophages,and some alterations could be associated with CFTR defect. Thus, perturbationsof CD11b and sCD14, involved in innate immune response, may play a potentialimportant role in CF pathogenesis. [ No other pdf]