Immune-triggering effect of the foodborne parasite Kudoa septempunctata through the C-type lectin Mincle in HT29 cells
BMB REPORTS
Authors: Shin, Ji-Hun; Yang, Jung-Pyo; Seo, Seung-Hwan; Kim, Sang-Gyun; Kim, Eun-Min; Ham, Do-Won; Shin, Eun-Hee
Abstract
Kudoa septempunctata is a myxozoan parasite that causes food poisoning in individuals consuming olive flounder. The present study aimed to investigate the currently insufficiently elucidated early molecular mechanisms of inflammatory responses in the intestine owing to parasite ingestion. After Kudoa spores were isolated from olive flounder, HT29 cells were exposed to spores identified to be alive using SYTO-9 and propidium iodide staining or to antigens of Kudoa spores (KsAg). IL-1 beta, IL-8, TNF-alpha and NFKB1 expression and NF-kappa B activation were assessed using real-time PCR, cytokine array and western blotting. The immunofluorescence of FITC-conjugated lectins, results of ligand binding assays using Mincle-Fc and IgG-Fc, CLEC4E expressions in response to KsAg stimulation, and Mincle-dependent NF-kappa B activation were assessed to clarify the early immune-triggering mechanism. Inflammatory cytokines (IL-1 beta, GM-CSF and TNF-alpha), chemokines (IL-8, CCL2, CCL5 and CXCL1) and NF-.B activation (pNF-kappa B/NF-kappa B) in HT29 cells increased following stimulation by KsAg. The immunofluorescence results of spores and lectins (concanavalin A and wheat germ agglutinin) suggested the importance of Mincle in molecular recognition between Kudoa spores and intestinal cells. Practically, data for Mincle-Fc and KsAg binding affinity, CLEC4E mRNA expression, Mincle immunofluorescence staining and hMincle-dependent NF-kappa B activation demonstrated the involvement of Mincle in the early immune-triggering mechanism. The present study newly elucidated that the molecular recognition and immune-triggering mechanism of K. septempunctata are associated with Mincle on human intestinal epithelial cells.
Downregulation of the CCL2/CCR2 and CXCL10/CXCR3 axes contributes to antitumor effects in a mouse model of malignant glioma
SCIENTIFIC REPORTS
Authors: Shono, Kenji; Yamaguchi, Izumi; Mizobuchi, Yoshifumi; Kagusa, Hiroshi; Sumi, Akiko; Fujihara, Toshitaka; Nakajima, Kohei; Kitazato, Keiko T.; Matsuzaki, Kazuhito; Saya, Hideyuki; Takagi, Yasushi
Abstract
Glioblastoma multiforme involves glioma stem cells (GSCs) that are resistant to various therapeutic approaches. Here, we studied the importance of paracrine signaling in the glioma microenvironment by focusing on the celecoxib-mediated role of chemokines C-C motif ligand 2 (CCL2), C-X-C ligand 10 (CXCL10), and their receptors, CCR2 and CXCR3, in GSCs and a GSC-bearing malignant glioma model. C57BL/6 mice were injected with orthotopic GSCs intracranially and divided into groups administered either 10 or 30 mg/kg celecoxib, or saline to examine the antitumor effects associated with chemokine expression. In GSCs, we analyzed cell viability and expression of chemokines and their receptors in the presence/absence of celecoxib. In the malignant glioma model, celecoxib exhibited antitumor effects in a dose dependent manner and decreased protein and mRNA levels of Ccl2 and CxcL10 and Cxcr3 but not of Ccr2. CCL2 and CXCL10 co-localized with Nestin(+) stem cells, CD16(+) or CD163(+) macrophages and Iba-1(+) microglia. In GSCs, celecoxib inhibited Ccl2 and Cxcr3 expression in a nuclear factor-kappa B-dependent manner but not Ccr2 and CxcL10. Moreover, Ccl2 silencing resulted in decreased GSC viability. These results suggest that celecoxib-mediated regulation of the CCL2/CCR2 and CXCL10/ CXCR3 axes may partially contribute to glioma-specific antitumor effects.