title: Dry eye-induced CCR7+CD11b+ cell lymph node homing is induced by COX-2 activities.
abstract: OBJECTIVE
  We aimed to determine the role of CCR7+CD11b+ cell lymph node (LN) homing and T-cell differentiation in dry eye (DE)-induced immunopathogenesis and investigate the therapeutic effects of cyclooxygenase-2 (COX-2) and prostaglandin E2/eicosanoid-prostanoid (PGE2/EP) inhibitors against DE.
  
  
  METHODS
  Six-week-old female C57BL/6 mice were housed in a controlled-environment chamber and administered topical selective COX-2 inhibitors or EP2 antagonists. Expression of major histocompatibility complex (MHC)-IIhigh, CD11b+, CCR7+, IFN-γ+, IL-17+, and CD4+ in the corneas and draining LNs was evaluated using flow cytometry. Mixed lymphocyte reactions (MLRs) with carboxyfluorescein diacetate succinimidyl ester labeling and intracellular cytokine staining were used to verify DE-induced corneal dendritic cell function. mRNA expression of COX-2, EPs, and proinflammatory cytokines in ocular surface was evaluated using quantitative RT-PCR and immunohistochemical staining.
  
  
  RESULTS
  Dry eye significantly increased MHC-IIhighCD11b+ and CCR7+CD11b+ cells in the cornea and LNs, and MLR revealed CCR7+CD11b+ cells from DE corneas stimulated IL-17+CD4+ cell proliferation. mRNA levels of COX-2, EP2, IFN-γ, TNF-α, IL-6, and IL-17 were significantly higher in DE ocular surface but were suppressed by topical COX-2 inhibitors and EP2-specific blockers. Immunohistochemical staining showed COX-2 and matrix metalloproteinase expression in DE corneal epithelia that was diminished by both topical treatments. Furthermore, both topical treatments significantly reduced frequencies of MHC-IIhigh, CD11b+, and CCR7+CD11b+ cells in the corneas and LNs, but also IL-17+CD4+ cells in LNs.
  
  
  CONCLUSIONS
  Topical COX-2/EP2 treatment reduces CCR7+CD11b+ cells on the ocular surface with inhibition of cellular LN homing and suppresses Th17 immune response, suggesting the COX-2/PGE2/EP axis contributes to immuno-inflammatory pathogenesis on the ocular surface and may be a novel therapeutic target in DE.
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Ji
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Seo
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Wungrak
authors.initials: W
authors.lastname: Choi
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Areum
authors.initials: A
authors.lastname: Yeo
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyemi
authors.initials: H
authors.lastname: Noh
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea Institute of Corneal Dystrophy Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea Institute of Corneal Dystrophy Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Lee
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000276:immunology*; D049109:Cell Proliferation; D003315:Cornea / Q000378:metabolism* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D015352:Dry Eye Syndromes / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D054400:Receptors, CCR7 / Q000276:immunology* / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000276:immunology / Q000378:metabolism
chemical_list: D039481:CD11b Antigen; C515371:Ccr7 protein, mouse; D012333:RNA, Messenger; D054400:Receptors, CCR7; D016201:Receptors, Lymphocyte Homing; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2
keywords: EP receptor; chemokine receptor CCR7; cyclooxygenase-2 (COX-2); dendritic cell; dry eye disease; prostaglandin E2