Decreased expression of HLA-DQ and HLA-DR on cells of the monocytic lineage in cystic fibrosis

AbstractWe studied HLA class II molecules on blood monocytesubsets, blood dendritic cells, sputum macrophages, andmonocyte-derived macrophages at the protein (flow cy-tometry) and mRNA level (RT-PCR) in adult patientswith cystic fibrosis (CF) and healthy control subjects asputative contributors to the CF phenotype. In healthydonors, we found a high average HLA-DQ expressionof 4.35 mean specific fluorescence intensity units(ΔMnI) on classical blood monocytes. In F508del ho-mozygous CF patients, the average ΔMnI was low(1.80). Patients were divided into two groups, in which14 of these patients had HLA-DQ expression above 2ΔMnI (average 3.25 ΔMnI, CF-DQ group1 ) and 36 below(average 1.24 ΔMnI, CF-DQ group2 ). Also, the CD16-positive monocyte subset and blood dendritic cellsshowed much lower levels of HLA-DQ for the CF-DQ group2 patients compared with healthy controls. Inmacrophages from sputum and derived from monocytes,in vitro HLA-DQ expression was dramatically decreasedto background levels in CF-DQ