title: Dendritic cells phenotype fitting under hypoxia or lipopolysaccharide; adenosine 5'-triphosphate-binding cassette transporters far beyond an efflux pump.
abstract: This study examines adenosine 5'-triphosphate-binding cassette (ABC) transporters as a potential therapeutic target in dendritic cell (DC) modulation under hypoxia and lipopolysaccharide (LPS). Functional capacity of dendritic cells (DCs) (mixed lymphocyte reaction: MLR) and maturation of iDCs were evaluated in the presence or absence of specific ABC-transporter inhibitors. Monocyte-derived DCs were cultured in the presence of interleukin (IL)-4/granulocyte-macrophage colony-stimulating factor (GM-CSF). Their maturation under hypoxia or LPS conditions was evaluated by assessing the expression of maturation phenotypes using flow cytometry. The effect of ABC transporters on DC maturation was determined using specific inhibitors for multi-drug resistance (MDR1) and multi-drug resistance proteins (MRPs). Depending on their maturation status to elicit T cell alloresponses, the functional capacity of DCs was studied by MLR. Mature DCs showed higher P-glycoprotein (Pgp) expression with confocal microscopy. Up-regulation of maturation markers was observed in hypoxia and LPS-DC, defining two different DC subpopulation profiles, plasmacytoid versus conventional-like, respectively, and different cytokine release T helper type 2 (Th2) versus Th1, depending on the stimuli. Furthermore, hypoxia-DCs induced more B lymphocyte proliferation than control-iDC (56% versus 9%), while LPS-DCs induced more CD8-lymphocyte proliferation (67% versus 16%). ABC transporter-inhibitors strongly abrogated DC maturation [half maximal inhibitory concentration (IC50 ): P-glycoprotein inhibition using valspodar (PSC833) 5 μM, CAS 115104-28-4 (MK571) 50 μM and probenecid 2·5 μM], induced significantly less lymphocyte proliferation and reduced cytokine release compared with stimulated-DCs without inhibitors. We conclude that diverse stimuli, hypoxia or LPS induce different profiles in the maturation and functionality of DC. Pgp appears to play a role in these DC events. Thus, ABC-transporters emerge as potential targets in immunosuppressive therapies interfering with DCs maturation, thereby abrogating innate immune response when it is activated after ischaemia.
authors.affiliation: Nephrology Department, IDIBELL-Hospital Universitari Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain. nuria.lloberas@yahoo.es
authors.forename: N
authors.initials: N
authors.lastname: Lloberas
authors.forename: I
authors.initials: I
authors.lastname: Rama
authors.forename: I
authors.initials: I
authors.lastname: Llaudó
authors.forename: J
authors.initials: J
authors.lastname: Torras
authors.forename: G
authors.initials: G
authors.lastname: Cerezo
authors.forename: L
authors.initials: L
authors.lastname: Cassis
authors.forename: M
authors.initials: M
authors.lastname: Franquesa
authors.forename: A
authors.initials: A
authors.lastname: Merino
authors.forename: D
authors.initials: D
authors.lastname: Benitez-Ribas
authors.forename: J M
authors.initials: JM
authors.lastname: Cruzado
authors.forename: I
authors.initials: I
authors.lastname: Herrero-Fresneda
authors.forename: O
authors.initials: O
authors.lastname: Bestard
authors.forename: J M
authors.initials: JM
authors.lastname: Grinyó
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002454:Cell Differentiation; D015687:Cell Hypoxia; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D007959:Lymphocyte Culture Test, Mixed; D016131:Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D010641:Phenotype
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D016207:Cytokines; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008070:Lipopolysaccharides; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C513055:ABCB1 protein, human; C497442:HIF1A protein, human; C421109:multidrug resistance-associated protein 1