HLA-DRhi and CCR9 Define a Pro-Inflammatory Monocyte Subset in IBD
CLINICAL AND TRANSLATIONAL GASTROENTEROLOGY
Authors: Linton, Ludvig; Karlsson, Mats; Grundstrom, Jeanette; Hjalmarsson, Eric; Lindberg, Annelie; Lindh, Emma; Glise, Hans; Befrits, Ragnar; Janczewska, Izabella; Karlen, Per; Winqvist, Ola; Eberhardson, Michael
Abstract
OBJECTIVES: It has been demonstrated that circulating monocytes relocate to the intestinal mucosa during intestinal inflammation, but the phenotype and inflammatory mechanisms of these monocytes remain poorly understood. Here, we have investigated blood monocytes expressing high levels of HLA-DR and CCR9 in patients with inflammatory bowel disease (IBD). METHODS: Fifty-one patients with mild to severe ulcerative colitis (UC; n = 31; UC-DAI 3-12) or Crohn's disease (CD; n = 20; Harvey-Bradshaw indices (HBI) 2-16) were included together with 14 controls, during IBD therapy for four consecutive weeks. The frequency of CD14(+)HLA-DR hi monocytes was monitored weekly in peripheral blood, using flow cytometry. The surface phenotype and cytokine profile of these monocytes were established using flow cytometry and real-time PCR. Clinical parameters were assessed weekly in all patients. RESULTS: The frequency of circulating CD14(+)HLA-DRhi monocytes was significantly higher in IBD patients with moderate to severe disease compared with healthy controls (P<0.001). During treatment with corticosteroids and granulocyte/monocyte apheresis, the proportion of circulating CD14(+)HLA-DR hi monocytes was significantly reduced. CD14(+)HLA-DR hi monocytes produced high levels of inflammatory mediators, such as tumor necrosis factor (TNF)-alpha, and expressed the gut-homing receptor CCR9. Furthermore, we found that the CCR9 ligand, CCL25/TECK, was expressed at high levels in the colonic mucosa in IBD patients with active disease. CONCLUSIONS: CD14(+)HLA-DR hi blood monocytes were increased in patients with active IBD. These monocytes exhibit a pro-inflammatory, gut-homing phenotype with regard to their TNF-alpha production and expression of CCR9. Our results suggest that these monocytes are important in mediating intestinal inflammation, and provide potential therapeutic targets in IBD.
Increased Expressions and Roles of CC Chemokine Ligand 21 and CC Chemokine Ligand 25 in Chronic Rhinosinusitis with Nasal Polyps
INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY
Authors: Liu, Meng-Zhi; Chen, Shi-Ming; Xu, Yu; Kong, Yong-Gang; Deng, Yu-Qin; Li, Fen; Tao, Ze-Zhang
Abstract
Introduction: Chronic rhinosinusitis (CRS) is a local inflammation of the nasal mucosa and sinus that persists for >12 weeks. As CC chemokine ligand (CCL) 19 expression is known to be elevated in CRS, and CCL 19, CCL21, and CCL25 share the same atypical chemokine receptor 4, so we focused on CCL21 and CCL25. Objectives: To investigate the expression of CCL21 and CCL25 in different types of CRS and their significance in CRS development. Methods: A total of 116 patients participated in the study, and uncinate process mucosa or nasal polyp (NP) specimens were collected during surgery. Western blotting and immunohistochemistry were performed to detect the expression of CCL21 and CCL25, respectively, in the nasal mucosa. Immunofluorescence was used to determine their cellular localization in NPs, whereas macrophage culture was used to determine their relationships with macrophages. Results: Immunohistochemistry revealed that the expressions of CCL21 and CCL25 were increased in NPs only. Western blotting revealed that these expressions were gradually increased in control, CRS without NP and CRS with NP groups and were positively correlated with disease severity. Furthermore, increased expressions of CCL21 and CCL25 in NPs were not related to eosinophil infiltration. Immunofluorescence results demonstrated colocalization of CCL25+ cells and CD68+ macrophages. CCL25 expression was increased in macrophage culture, especially in M1 macrophages, while CCL21 expression was not significantly associated with macrophages. Conclusions: CCL21 and CCL25 were significantly upregulated in NPs and positively correlated with disease severity. CCL25 upregulation was related to M1 macrophages.