Chemokine receptor CCR8 is required for lipopolysaccharide-triggered cytokine production in mouse peritoneal macrophages.
Chemokine (C-C motif) receptor 8 (CCR8), the chemokine receptor for chemokine (C-C motif) ligand 1 (CCL1), is expressed in T-helper type-2 lymphocytes and peritoneal macrophages (PMφ) and is involved in various pathological conditions, including peritoneal adhesions. However, the role of CCR8 in inflammatory responses is not fully elucidated. To investigate the function of CCR8 in macrophages, we compared cytokine secretion from mouse PMφ or bone marrow-derived macrophages (BMMφ) stimulated with various Toll-like receptor (TLR) ligands in CCR8 deficient (CCR8-/-) and wild-type (WT) mice. We found that CCR8-/- PMφ demonstrated attenuated secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 when stimulated with lipopolysaccharide (LPS). In particular, LPS-induced IL-10 production absolutely required CCR8. CCR8-dependent cytokine secretion was characteristic of PMφ but not BMMφ. To further investigate this result, we selected the small molecule compound R243 from a library of compounds with CCR8-antagonistic effects on CCL1-induced Ca2+ flux and CCL1-driven PMφ aggregation. Similar to CCR8-/- PMφ, R243 attenuated secretion of TNF-α, IL-6, and most strikingly IL-10 from WT PMφ, but not BMMφ. CCR8-/- PMφ and R243-treated WT PMφ both showed suppressed c-jun N-terminal kinase activity and nuclear factor-κB signaling after LPS treatment when compared with WT PMφ. A c-Jun signaling pathway inhibitor also produced an inhibitory effect on LPS-induced cytokine secretion that was similar to that of CCR8 deficiency or R243 treatment. As seen in CCR8-/- mice, administration of R243 attenuated peritoneal adhesions in vivo. R243 also prevented hapten-induced colitis. These results are indicative of cross talk between signaling pathways downstream of CCR8 and TLR-4 that induces cytokine production by PMφ. Through use of CCR8-/- mice and the new CCR8 inhibitor, R243, we identified a novel macrophage innate immune response pathway that involves a chemokine receptor.
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan; Department of Dermatology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
Tomoyuki
T
Oshio
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan; Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan.
Rei
R
Kawashima
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Yuki I
YI
Kawamura
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Teruki
T
Hagiwara
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Noriko
N
Mizutani
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Toshihiko
T
Okada
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Takeshi
T
Otsubo
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Kyoko
K
Inagaki-Ohara
Department of Pathology & Experimental Medicine, Okayama University, Okayama, Okayama, Japan.
Akihiro
A
Matsukawa
Department of Life Science, Gakushuin University, Mejiro-ku, Tokyo, Japan.
Tatsuya
T
Haga
Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Shigeru
S
Kakuta
Division of Experimental Animal Immunology, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan.
Yoichiro
Y
Iwakura
Department of Applied Chemistry, Faculty of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan.
Seijiro
S
Hosokawa
Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Taeko
T
Dohi
D000818:Animals; D054402:Chemokine CCL1 / Q000037:antagonists & inhibitors; D002633:Chemotaxis / Q000187:drug effects / Q000276:immunology; D003092:Colitis / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis*; D004195:Disease Models, Animal; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D042541:Intracellular Space / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D021381:Protein Transport; D054401:Receptors, CCR8 / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D051193:Toll-Like Receptors / Q000378:metabolism
D054402:Chemokine CCL1; D016207:Cytokines; D008070:Lipopolysaccharides; D054401:Receptors, CCR8; D051193:Toll-Like Receptors