Polycyclic Aromatic Hydrocarbons Inhibit Differentiation of Human Monocytes into Macrophages This information is current as Julien van Grevenynghe, Sophie Rion, Eric Le Ferrec, Marc of September 23, 2021. Le Vee, Laurence Amiot, Renée Fauchet and Olivier Fardel J Immunol 2003; 170:2374-2381; ; doi: 10.4049/jimmunol.170.5.2374 http://www.jimmunol.org/content/170/5/2374 Downloaded from References This article cites 44 articles, 15 of which you can access for free at: http://www.jimmunol.org/content/170/5/2374.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! 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The Journal of Immunology Polycyclic Aromatic Hydrocarbons Inhibit Differentiation of Human Monocytes into Macrophages1 Julien van Grevenynghe,2* Sophie Rion,2* Eric Le Ferrec,* Marc Le Vee,* Laurence Amiot,† Rene´e Fauchet,† and Olivier Fardel3*† Polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BP) are ubiquitous environmental carcinogenic contaminants exerting deleterious effects toward cells acting in the immune defense such as monocytic cells. To investigate the cellular basis involved, we have examined the consequences of PAH exposure on macrophagic differentiation of human blood monocytes. Treatment by BP markedly inhibited the formation of adherent macrophagic cells deriving from monocytes upon the action of either GM-CSF or M-CSF. Moreover, it reduced expression of macrophagic phenotypic markers such as CD71 and CD64 in GM-CSF-treated monocytic cells, without altering cell viability or inducing an apoptotic process. Exposure to BP also strongly altered functional properties characterizing macrophagic cells such as endocytosis, phagocytosis, LPS-triggered production of Downloaded from TNF-␣ and stimulation of allogeneic lymphocyte proliferation. Moreover, formation of adherent macrophagic cells was decreased in response to PAHs distinct from BP such as dimethylbenz(a)anthracene and 3-methylcholanthrene, which interact, like BP, with the arylhydrocarbon receptor (AhR) known to mediate many PAH effects. In contrast, benzo(e)pyrene, a PAH not activating AhR, had no effect. In addition, AhR was demonstrated to be present and functional in cultured monocytic cells, and the use of its antagonist ␣-naphtoflavone counteracted inhibitory effects of BP toward macrophagic differentiation. Overall, these data dem- onstrate that exposure to PAHs inhibits functional in vitro differentiation of blood monocytes into macrophages, likely through an http://www.jimmunol.org/ AhR-dependent mechanism. Such an effect may contribute to the immunotoxicity of these environmental carcinogens owing to the crucial role played by macrophages in the immune defense. The Journal of Immunology, 2003, 170: 2374–2381. olycyclic aromatic hydrocarbons (PAHs)4 represent an im- and ultimately interaction with xenobiotic responsive elements portant class of widely distributed environmental contam- found in the 5Ј flanking regions of responsive genes (6). In this P inants. They are usually formed through the combustion of way, AhR is notably implicated in up-regulation of drug-metabo- fossil fuel and the burning of various substances and are found in lizing enzymes such as cytochromes P450 (CYPs), especially significant amounts in automobile exhaust, cigarette smoke, vari- CYP1A1 (7), which metabolize PAHs into reactive intermediates by guest on September 23, 2021 ous foods, and industrial waste by-products (1). They can exert that are capable of interacting with DNA and most likely account major toxic effects, including development of cancers in various for mutagenic properties of these environmental contaminants (8). tissues, cardiovascular diseases, loss of fertility, and immunosup- Immunosuppression due to PAHs, which may indirectly contrib- pression (2–5). Many of these adverse effects are thought to be ute to their carcinogenic properties, also involves (at least in part) linked to the cytosolic arylhydrocarbon receptor (AhR), a ligand- AhR, because the AhR antagonist ␣-naphtoflavone counteracts dependent basic helix-loop-helix transcription factor to which some adverse effects of PAHs toward immune cells (4, 9). How- PAHs bind, thereby triggering translocation of the AhR into the ever, cellular and molecular mechanisms involved in PAH-related nucleus, association with the AhR nuclear translocator (ARNT), immunotoxicity remain incompletely understood, especially for hu- man cells, because most published studies have been performed on mice (9–11). Lymphocytes likely constitute important targets. In- *Faculte´de Pharmacie, Institut National de la Sante´et de la Recherche Me´dicale, deed, potent immunosuppressive PAHs such as benzo(a)pyrene Rennes, France; and †Faculte´deMe´decine, Laboratoire Universitaire d’He´matologie et de la Biologie des Cellules Sanguines, Rennes, France (BP) and dimethylbenz(a)anthracene (DMBA) inhibit murine T and B cell proliferation and alter T cell-related cytokine production and Received for publication July 10, 2002. Accepted for publication December 17, 2002. B cell-mediated Ab production (11–13). They also suppress mito- The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance genesis of human T lymphocytes (14) and alter B cell lymphopoie- with 18 U.S.C. Section 1734 solely to indicate this fact. sis through triggering pre-B lymphocyte apoptosis (15). 1 This work was supported by grants from the Institut National de Recherche et de Besides lymphocytes, APCs such as macrophages and dendritic Se´curite´and the Ministe`re de l’Ame´nagement du Territoire et de l’Environnement. cells can also be affected by PAHs. Indeed, PAHs impair Ag pre- J.v.G. and S.R. are recipients of fellowships from the Ligue Nationale contre le Can- cer (Comite´ des Coˆtes d’Armor) and the Fondation pour la Recherche Me´dicale, sentation by mouse macrophages (16), alter T cell-macrophage respectively. interaction (17), and suppress phagocytic activity of peritoneal 2 J.v.G. and S.R. contributed equally to this study. macrophages (18). BP also reduced esterase-positive macrophagic 3 Address correspondence and reprint requests to Dr. Olivier Fardel, Institut National cell population in mouse spleen (19). In fact, murine splenic mac- de la Sante´et de la Recherche Me´dicale Unité 456, Faculte´de Pharmacie, 2 avenue rophages, which have been demonstrated to metabolize PAHs du Pr. L. Bernard, 35043 Rennes, France. E-mail address: olivier.fardel@univ- rennes1.fr (20), are considered the cell types targeted by BP among the dif- 4 Abbreviations used in this paper: PAH, polycyclic aromatic hydrocarbon; AhR, ferent splenic cell populations and are responsible for PAH-related arylhydrocarbon receptor; ARNT, AhR nuclear translocator; CYP, cytochrome P450; suppression of splenic humoral immune response (21). Moreover, BP, benzo(a)pyrene; DMBA, dimethylbenz(a)anthracene; MC, 3-methylcholan- threne; BeP, benzo(e)pyrene; WST-1, 4-3-(4(iodophenyl)-2-(4-nitrophenyl)-2H-5tet- it is noteworthy that cigarette smoke condensates, whose major razole]-1,3-benzene disulfonate; MFI, mean fluorescence intensity. components consist of PAHs, markedly down-regulate functional Copyright © 2003 by The American Association of Immunologists, Inc. 0022-1767/03/$02.00 The Journal of Immunology 2375 capacities of macrophages (22). More specialized APCs, i.e., densed or fragmented chromatin, were counted. Results were expressed as Langerhans cells, have also been found to be altered after topical percentages of the total cell number. application of DMBA (23). Interestingly, PAHs have been recently demonstrated to strongly impair functional differentiation and mat- Flow cytometric immunolabeling assays uration of human monocytes into dendritic cells (24). This indi- Phenotypic analysis of monocytic cells was performed using flow cyto- cates that differentiation pathways of monocytes may be compro- metric direct or indirect immunofluorescence as previously described (24). mised by PAHs. Owing to the fact that macrophages are likely Cells were first incubated for 30 min in PBS with 5% human AB serum at 4°C to avoid any nonspecific mAb binding. Several mAbs were then used major targets of PAHs as reported above, it is tempting to specu- for direct or indirect immunofluorescence labeling: PE-conjugated mouse late that PAHs may affect not only dendritic cell differentiation, but mAbs against CD11b and CD40; FITC-conjugated Abs directed against also macrophage generation from monocytes. To test such a hy- CD14, CD16, CD86, CD80, HLA class I, HLA class II, CD71, CD64, Ј pothesis, in the present study we have examined the effects of PAH CD11a, CD11c, CD29, CD36, CD49e,