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Purpose: A strong immunosuppressive tumor microenvironment (TME) represents the major barrier responsible for the failure of current immunotherapy approaches in treating Glioblastoma Multiforme (GBM). Within the TME, the regulatory T cells (Tregs) exert immunosuppressive effects on CD8 + T cell - mediated anti-cancer immune killing. Consequently, targeting and inhibiting their immunosuppressive function emerges as an effective therapeutic strategy for GBM. The present study aimed to investigate the mechanisms and effects of Suberanilohydroxamic Acid (SAHA), a histone deacetylase inhibitor, on immunosuppressive Tregs., Methods: The tumor-infiltrating immune cells in the immunocompetent GBM intracranial implanted xenograft mouse model were analyzed by immunohistochemistry and flow cytometry techniques. The mRNA expressions were assessed through the RT-qPCR method, while the related protein expressions were determined using western blot, ELISA, immunofluorescence (IF), and flow cytometry techniques. The relationship between c-Myc and C-C motif Chemokine Ligand 1 (CCL1) promotor was validated through a dual-luciferase reporter assay system and chromatin immunoprecipitation., Results: SAHA suppressed effectively tumor growth and extended significantly overall survival in the immunocompetent GBM intracranial xenograft mouse model. Additionally, it promoted the infiltration of CD8 + T lymphocytes while suppressed the infiltration of CD4 + CD25 + Tregs. Furthermore, SAHA enhanced anti-PD-L1 immune therapy in the intracranial xenograft of mice. Mechanistically, SAHA exerted its effects by inhibiting histone deacetylase 2 (HDAC2), thereby suppressing the binding between c-Myc and the CCL1 promotor., Conclusion: SAHA inhibited the binding of c-Myc with the CCL1 promoter and then suppressed the transcription of CCL1.Additionally, it effectively blocked the interplay of CCL1-CCR8, resulting in reduced activity of Tregs and alleviation of tumor immunosuppression., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The human CC chemokine receptor 8 (CCR8) has been extensively pursued as target for the treatment of various inflammatory disorders. More recently, the importance of CCR8 in the tumor microenvironment has been demonstrated, spurring the interest in CCR8 antagonism as therapeutic strategy in immuno-oncology. On a previously described naphthalene sulfonamide with CCR8 antagonistic properties, the concept of isosterism was applied, leading to the discovery of novel CCR8 antagonists with IC 50 values in the nM range in both the CCL1 competition binding and CCR8 calcium mobilization assay. The excellent CCR8 antagonistic activity of the most potent congeners was rationalized by homology molecular modeling., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yenthel Verhaegen reports financial support was provided by Fund for Scientific Research. Libao Liu reports financial support was provided by Guangzhou Elite Project. Steven De Jonghe has patent #Novel CCR8 antagonists pending to KU Leuven. Tom Van Loy has patent #Novel CCR8 antagonists pending to KU Leuven. Dominique Schols has patent #Novel CCR8 antagonists pending to KU Leuven. Wim Dehaen has patent #Novel CCR8 antagonists pending to KU Leuven. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The C-C motif chemokine receptor 8 (CCR8) is a class A G-protein coupled receptor that has emerged as a promising therapeutic target in cancer. Targeting CCR8 with an antibody has appeared to be an attractive therapeutic approach, but the molecular basis for chemokine-mediated activation and antibody-mediated inhibition of CCR8 are not fully elucidated. Here, we obtain an antagonist antibody against human CCR8 and determine structures of CCR8 in complex with either the antibody or the endogenous agonist ligand CCL1. Our studies reveal characteristic antibody features allowing recognition of the CCR8 extracellular loops and CCL1-CCR8 interaction modes that are distinct from other chemokine receptor - ligand pairs. Informed by these structural insights, we demonstrate that CCL1 follows a two-step, two-site binding sequence to CCR8 and that antibody-mediated inhibition of CCL1 signaling can occur by preventing the second binding event. Together, our results provide a detailed structural and mechanistic framework of CCR8 activation and inhibition that expands our molecular understanding of chemokine - receptor interactions and offers insight into the development of therapeutic antibodies targeting chemokine GPCRs., (© 2023. The Author(s).)

Macrophage M2 polarization has been identified in the pathogenesis of pulmonary fibrosis (PF), but the mediators that drive the macrophage M2 program in PF need to be clarified. We showed that the expression of AMFR and CCR8, two known receptors of CCL1, was increased in macrophages from lungs of mice with bleomycin (BLM)-induced PF. Deficiency in either AMFR or CCR8 in macrophages protected mice from BLM-induced PF. In vitro experiments revealed that CCL1 recruited macrophages by binding to its classical receptor CCR8 and drove the macrophage M2 phenotype via its interaction with the recently identified receptor AMFR. Mechanistic studies revealed that the CCL1-AMFR interaction enhanced CREB/C/EBPβ signaling to promote the macrophage M2 program. Together, our findings reveal that CCL1 acts as a mediator of macrophage M2 polarization and could be a therapeutic target in PF., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Since the lung is one of the most common sites for cancer metastasis, it could provide a suitable microenvironment for pre-metastatic niche (PMN) formation to facilitate tumor cell colonization. Regulatory T cells (Tregs) are an immunosuppressive cell type found ubiquitously in tumors and may play a crucial role in PNM formation. In this study, we investigated tumor-derived exosome (TDE)-induced Treg differentiation in the lung PMN as well as the underlying mechanisms., Methods: TDEs were isolated from the Lewis lung carcinoma cell line (LLC-exo) and their effects on mouse pulmonary fibroblasts was investigated in vitro as well as on lung tumor formation and metastasis in a pre-injected mouse model. Immune cell populations in the lung were analyzed by flow cytometry. Expression of CCL1 and CCR8 was evaluated by immunofluorescence staining, qRT-PCR and Western blot analyses. Cytokine expression was measured using mouse cytokine arrays and ELISA., Results: The number of CD4 + FoxP3 + Tregs was significantly increased in lungs in a LLC-exo pre-injected mouse model. Lung fibroblasts secreted increased amounts of CCL1 after co-culture with LLC-exo, which induced Treg differentiation by activating its specific receptor CCR8, ultimately contributing to the establishment of an immunologically tolerant PMN. Moreover, inhibiting the release of LLC-exo by GW4869, or blocking the CCL1-CCR8 axis using AZ084, suppressed Tregs differentiation and tumor metastasis in the lung., Conclusions: Collectively, our study provides a novel mechanism by which Tregs are activated to form an immunologically tolerant PMN and demonstrates a critical link among lung fibroblasts, Tregs and metastatic tumor cells., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Recruitment of immune cells to the site of inflammation by the chemokine CCL1 is important in the pathology of inflammatory diseases. Here, we examined the role of CCL1 in pulmonary fibrosis (PF). Bronchoalveolar lavage fluid from PF mouse models contained high amounts of CCL1, as did lung biopsies from PF patients. Immunofluorescence analyses revealed that alveolar macrophages and CD4 + T cells were major producers of CCL1 and targeted deletion of Ccl1 in these cells blunted pathology. Deletion of the CCL1 receptor Ccr8 in fibroblasts limited migration, but not activation, in response to CCL1. Mass spectrometry analyses of CCL1 complexes identified AMFR as a CCL1 receptor, and deletion of Amfr impaired fibroblast activation. Mechanistically, CCL1 binding triggered ubiquitination of the ERK inhibitor Spry1 by AMFR, thus activating Ras-mediated profibrotic protein synthesis. Antibody blockade of CCL1 ameliorated PF pathology, supporting the therapeutic potential of targeting this pathway for treating fibroproliferative lung diseases., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Mechanical, metabolic, inflammatory, and immune factors contribute to the development of osteoarthritis (OA), a joint disease characterized by cartilage destruction. The circular RNA (circRNA) hsa_circ_0134111 is upregulated in the cartilage of OA patients; however, its potential role in OA pathogenesis and progression remains unexplored. In this study, the effects of hsa_circ_0134111 knockdown were evaluated in primary human chondrocytes treated with IL-1β to simulate OA, as well as in a rat model of OA. Hsa_circ_0134111 expression was upregulated in IL-1β-stimulated chondrocytes. CCK-8 and flow cytometry assays showed that hsa_circ_0134111 knockdown reversed IL-1β-induced cell decline by inhibiting apoptosis. Following prediction analysis of circRNA and miRNA targets, dual-luciferase reporter and silencing/overexpression assays suggested that a regulatory network composed of hsa_circ_0134111, miR-224-5p, and CCL1 modulates IL-1β-mediated OA-like effects in chondrocytes. Accordingly, CCL1 overexpression abrogated the prosurvival effects of hsa_circ_0134111 knockdown in vitro . Moreover, hsa_circ_0134111 silencing in vivo alleviated cartilage destruction in an OA rat model, decreased IL-6 and TNF-α levels in synovial fluid, and downregulated CCL1 expression in the affected joints. These results suggest that hsa_circ_0134111 contributes to OA development by binding to miR-224-5p, thereby releasing the inhibition that miR-224-5p exerts over CCL1.

The human CC chemokine receptor 8 (CCR8) is a promising drug target for cancer immunotherapy and autoimmune disease. Besides human and viral chemokines, previous studies revealed diverse classes of CCR8-targeting small molecules. We characterized a selection of these CCR8 ligands (hCCL1, vCCL1, ZK756326, AZ6; CCR8 agonists and a naphthalene-sulfonamide-based CCR8 antagonist), in in vitro cell-based assays (hCCL1 AF647 binding, calcium mobilization, cellular impedance, cell migration, β-arrestin 1/2 recruitment), and used pharmacological tools to determine G protein-dependent and -independent signaling pathways elicited by these ligands. Our data reveal differences in CCR8-mediated signaling induced by chemokines versus small molecules, which was most pronounced in cell migration studies. Human CCL1 most efficiently induced cell migration whereby Gβγ signaling was indispensable. In contrast, Gβγ signaling did not contribute to cell migration induced by other CCR8 ligands (vCCL1, ZK756326, AZ6). Although all tested CCR8 agonists were full agonists for calcium mobilization, a significant contribution for Gβγ signaling herein was only apparent for human and viral CCL1. Despite both Gα i - and Gα q -signaling regulate intracellular Ca 2+ -release, cellular impedance experiments showed that CCR8 agonists predominantly induce Gα i -dependent signaling. Finally, small molecule agonists displayed higher efficacy in β-arrestin 1 recruitment, which occurred independently of Gα i signaling. Also in this latter assay, only hCCL1-induced activity was dependent on Gβγ-signaling. Our study provides insight into CCR8 signaling and function and demonstrates differential CCR8 activation by different classes of ligands. This reflects the ability of CCR8 small molecules to evoke different subsets of the receptor's signaling repertoire, which categorizes them as biased agonists., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

In this study we investigated the effects of snake venom Group IA secreted phospholipase A 2 (svGIA) on the release of inflammatory and angiogenic mediators from human lung macrophages (HLMs). HLMs were incubated with lipopolysaccharide (LPS) or svGIA with or without macrophage-polarizing stimuli (IL-4, IL-10, IFN-γ or the adenosine analogue NECA). M2-polarizing cytokines (IL-4 and IL-10) inhibited TNF-α, IL-6, IL-12, IL-1β, CXCL8 and CCL1 release induced by both LPS and svGIA. IL-4 inhibited also the release of IL-10. IFN-γ reduced IL-10 and IL-12 and increased CCL1 release by both the LPS and svGIA-stimulated HLMs, conversely IFN-γ reduced IL-1β only by svGIA-stimulated HLMs. In addition, IFNγ promoted TNF-α and IL-6 release from svGIA-stimulated HLMs to a greater extent than LPS. NECA inhibited TNF-α and IL-12 but promoted IL-10 release from LPS-stimulated HLMs according to the well-known effect of adenosine in down-regulating M1 activation. By contrast NECA reduced TNF-α, IL-10, CCL1 and IL-1β release from svGIA-activated HLM. IL-10 and NECA increased both LPS- and svGIA-induced vascular endothelial growth factor A (VEGF-A) release. By contrast, IL-10 reduced angiopoietin-1 (ANGPT1) production from activated HLMs. IFN-γ and IL-4 reduced VEGF-A and ANGPT1 release from both LPS- and svGIA-activated HLMs. Moreover, IL-10 inhibited LPS-induced ANGPT2 production. In conclusion, we demonstrated a fine-tuning modulation of svGIA-activated HLMs differentially exerted by the classical macrophage-polarizing cytokines., (Copyright © 2020. Published by Elsevier Ltd.)

We previously reported higher levels of C-C chemokine ligand (CCL) 1 in the bronchoalveolar lavage (BAL) fluid (BALF) of patients with sarcoidosis than in BALF of patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD), indicating that CCL1 might act as a marker of disease activity in sarcoidosis. Notably, less invasive sampling sources are desirable, as BAL cannot always be performed due to its inherent risk. In this study, we sought to decipher the correlation between serum levels of CCL1 and clinical characteristics of sarcoidosis. Serum samples were obtained from 44 patients with clinically confirmed sarcoidosis, 14 patients with IgG4-RD, and 14 healthy controls. The clinical and radiological findings were retrospectively evaluated. Serum levels of CCL1 were measured using a sandwich enzyme-linked immunosorbent assay. Serum levels of other 17 cytokines and chemokines were measured using a MILLIPLEX® MAP KIT and Luminex® magnetic beads. Serum levels of CCL1 were significantly higher in patients with sarcoidosis than in patients with IgG4-RD and healthy controls. Serum CCL1 was positively correlated with the degree of hilar lymph node swelling on chest computed tomography and serum levels of soluble interleukin 2 receptor. Positive correlations were also observed between serum CCL1 and total cell counts, lymphocyte counts in BALF, and serum T helper 1 mediators such as IP-10 and TNF-α in patients with sarcoidosis. Serum CCL1 levels were significantly elevated in sarcoidosis and correlated with clinical parameters of the disease. In addition, serum and BALF levels of CCL1 were positively correlated in a statistically significant manner. Although further research in this field is necessary, CCL1 might have the potential to be a reliable serological marker of disease activity in sarcoidosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Tumor-derived extracellular vesicles are important mediators of cell-to-cell communication during tumorigenesis. Here, we demonstrated that hepatocellular carcinoma (HCC)-derived ectosomes remodel the tumor microenvironment to facilitate HCC progression in an ectosomal PKM2-dependent manner. HCC-derived ectosomal PKM2 induced not only metabolic reprogramming in monocytes but also STAT3 phosphorylation in the nucleus to upregulate differentiation-associated transcription factors, leading to monocyte-to-macrophage differentiation and tumor microenvironment remodeling. In HCC cells, sumoylation of PKM2 induced its plasma membrane targeting and subsequent ectosomal excretion via interactions with ARRDC1. The PKM2-ARRDC1 association in HCC was reinforced by macrophage-secreted cytokines/chemokines in a CCL1-CCR8 axis-dependent manner, further facilitating PKM2 excretion from HCC cells to form a feedforward regulatory loop for tumorigenesis. In the clinic, ectosomal PKM2 was clearly detected in the plasma of HCC patients. This study highlights a mechanism by which ectosomal PKM2 remodels the tumor microenvironment and reveals ectosomal PKM2 as a potential diagnostic marker for HCC., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A greater demand for food animal production without antibiotics has created the common practice of feeding food animals dietary immunomodulatory feed additives (IFA) throughout their life cycle. However, little is known about the impact of IFA on cytokine and chemokine signaling in non-stressed, non-pathogen-challenged food animals during the early feeding period. We evaluated the expression of 82 genes related to cytokine and chemokine signaling in the whole blood of growing Angus heifers to determine the effect of IFA supplementation on cytokine and chemokine signaling during the first 28 d of feeding. One gene ( CCL1 ) was significantly up-regulated and 14 genes (17%) were significantly down-regulated by IFA feeding during the entire early feeding period including 5 of 21 (24%) evaluated chemokine and IL receptors (CCR1 , CCR2 , IL1R1 , IL10RA , IL10RB ). These data when taken together suggest providing an IFA in the diet of growing beef cattle during the early feeding period may suppress the inflammatory response through cytokine-cytokine receptor signaling.

Chronic postoperative pain might be a pivotal component hindering recovery and regains the function after bone fracture and orthopedic surgery. However, the underlying mechanisms remain largely unclear. AMPA receptor of excitatory synapses is considered due to its critical role in pathologic pain. Chemokine CCL1 related neuroinflammation plays a role in excitatory synaptic transmission and nociceptive transduction. This study examined whether spinal CCL1 is associated with fracture-associated postoperative pain via AMPA receptor. We herein discovered that the tibial fracture with orthopedic surgery initiated and maintained chronic postoperative pain along with spinal up-regulation of CCL1/CCR8 expression and phosphorylation of GluA1-containing AMPA receptor. Central CCL1/CCR8 inhibition impaired mechanical and cold allodynia, and phosphorylated GluA1-containing AMPA receptor in the spinal dorsal horn. Intrathecal injection of GluA1-containing AMPA receptor antagonist NASPM alleviated fracture-related postoperative pain. Also, exogenous CCL1 delivery facilitated acute pain behaviors and spinal phosphorylation of GluA1-containing AMPA receptor in naïve mice, reversing by co-application of NASPM. Our current results indicated that spinal CCL1/CCR8-mediated GluA1-containing AMPA receptor activation is vital in the pathogenesis of fracture associated postoperative pain in mice., (Copyright © 2019. Published by Elsevier B.V.)

Objectives: Gadolinium (Gd) affects microglial polarization during remyelination. We previously reported that the suppression of proinflammatory microglia was neuroprotective in intracerebral haemorrhage (ICH). The objective of the present study was to investigate the effects of Gd on microglial polarization and neuronal injury after ICH., Methods: Gadolinium was intraperitoneally administered to ICH mice prepared by an intrastriatal microinjection of collagenase type VII. The polarization of M1, 2a, b and c microglia was evaluated by real-time PCR using the respective markers. Changes in representative mRNAs were also confirmed by immunological methods. Neuroprotective effects were evaluated by counting NeuN-positive cells and a behavioural analysis., Key Findings: One day after ICH, the mRNA levels of proinflammatory M1 microglial markers, such as inducible nitric oxide synthase (iNOS), and anti-inflammatory M2 microglial markers, such as arginase1 (M2a, c), Ym1 (M2a), and transforming growth factor-β (M2c), increased, while those of chemokine CCL1 (M2b) only increased after 3 days. Gd decreased the levels of all M1 and M2 markers. Arginase1 and iNOS protein levels also increased, and Gd reduced them due to apoptotic cell death. Gadolinium attenuated oedema, neuron loss, neurological deficits and the mortality rate without affecting haematoma sizes., Conclusions: Gadolinium induced M1 and M2 microglial apoptosis and exerted acute neuroprotective effects after ICH., (© 2020 Royal Pharmaceutical Society.)

Group 2 innate lymphoid cells (ILC2s) possess indispensable roles during type 2-mediated inflammatory diseases. Although their physiological and detrimental immune functions seem to depend on the anatomical compartment they reside, their tissue tropism and the molecular and immunological processes regulating the self-renewal of the local pool of ILC2s in the context of inflammation or infection are incompletely understood. Here, we analyzed the role of the CC-chemokine receptor CCR8 for the biological functions of ILC2s. In vitro and in vivo experiments indicated that CCR8 is in comparison to the related molecule CCR4 less important for migration of these cells. However, we found that activated mouse and human ILC2s produce the CCR8 ligand CCL1 and are a major source of CCL1 in vivo. CCL1 signaling to ILC2s regulates their proliferation and supports their capacity to protect against helminthic infections. In summary, we identify a novel chemokine receptor-dependent mechanism by which ILC2s are regulated during type 2 responses., (© 2019 Knipfer et al.)

The development of effective therapies against brain metastasis is currently hindered by limitations in our understanding of the molecular mechanisms driving it. Here we define the contributions of tumour-secreted exosomes to brain metastatic colonization and demonstrate that pre-conditioning the brain microenvironment with exosomes from brain metastatic cells enhances cancer cell outgrowth. Proteomic analysis identified cell migration-inducing and hyaluronan-binding protein (CEMIP) as elevated in exosomes from brain metastatic but not lung or bone metastatic cells. CEMIP depletion in tumour cells impaired brain metastasis, disrupting invasion and tumour cell association with the brain vasculature, phenotypes rescued by pre-conditioning the brain microenvironment with CEMIP + exosomes. Moreover, uptake of CEMIP + exosomes by brain endothelial and microglial cells induced endothelial cell branching and inflammation in the perivascular niche by upregulating the pro-inflammatory cytokines encoded by Ptgs2, Tnf and Ccl/Cxcl, known to promote brain vascular remodelling and metastasis. CEMIP was elevated in tumour tissues and exosomes from patients with brain metastasis and predicted brain metastasis progression and patient survival. Collectively, our findings suggest that targeting exosomal CEMIP could constitute a future avenue for the prevention and treatment of brain metastasis.

MicroRNAs (miRNA) play important roles in neuroinflammation and neuropathic pain development; however, the underlying mechanism requires further investigation. The expression of miR-21-5p was remarkably upregulated in chronic constrictive injury (CCI) rat model. A significant alleviated neuropathic pain development and reduced the expression of cytokines was observed in CCI rat after exogenous injection of miR-21-5p mimic. The dual-luciferase analysis revealed that tissue inhibitor of metalloproteinase-3 (TIMP3) and chemokines C-C motif ligand 1 (CCL1) was direct downstream target of miR-21-5p. Moreover, silencing of TIMP3 and CCL1 could rescue mechanical allodynia, thermal hyperalgesia and cytokine release in CCI rat, suggesting that TIMP3 and CCL1 exert their function by mediating neuroinflammation in neuropathic pain development. Therefore, we have identified a novel miR-21-5p-CCL1/TIMP3-cytokine axis in regulation of neuropathic pain development in CCI rat model, which is valuable for enhancing our understanding of neuropathic pain and developing miRNAs as potential therapeutic options in the future., (© 2019 Wiley Periodicals, Inc.)

Development, course of disease and prognosis of hepatocellular carcinomas (HCC) are strongly influenced by the immune system. Immunosuppressive regulatory T cells (Treg) have been shown to negatively impact disease progression and survival. To further understand the mechanisms of Treg attraction to HCC lesions, this study provides an analysis of Treg attracting chemokines in human HCC tissues. We analysed the expression of the Treg attracting chemokines CCL1 and CCL22 as well as the infiltration of FoxP3+ Treg and CD8+ T cells in paraffin-embedded tissue sections of 62 HCC patients. Expression of both chemokines was detected in 47 of 62 tissue slides. Chemokine expression was generally higher in tumour stroma and peritumoural liver tissue than in the tumour tissue itself. CD8+ T cells and FoxP3+ Treg were found at high levels in many tumour tissues. Intratumoural infiltration of Treg positively correlated with CCL22 levels in peritumoural liver tissue. In contrast, no correlation of Treg numbers and expression of CCL1 was detected. In summary, we describe here that the chemokines CCL1 and CCL22 are expressed in HCC tissues and, to a higher extent, in the stroma and peritumoural liver tissue. CCL22 may contribute to Treg recruitment and immunosuppression, whereas the role of CCL1 remains to be defined. It will be interesting to investigate the potential of these chemokines as drug targets for cancer therapy., (Copyright © 2019 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Background: We previously reported that the cytokine profiles in the bronchoalveolar lavage fluid (BALF) of IgG4-related respiratory disease (IgG4-RRD) more closely resemble the T-helper (Th) 2 response than sarcoidosis. The present study aimed to assess the chemokines in the BALF of IgG4-RRD and sarcoidosis in order to evaluate any possible associations between these chemokines and other markers., Methods: We examined 12 chemokines using a MILLIPLEX® MAP Kit (Millipore, Darmstadt, Germany) in the same BALF samples of the same 44 patients (IgG4-RRD, n = 11; sarcoidosis, n = 33) in which we had previously evaluated the cytokines., Results: The levels of CC-chemokine ligand (CCL)26 in the BALF of IgG4-RRD patients (median 24.5, range 3.1-401.1 pg/mL) were significantly higher than those in the BALF of sarcoidosis patients (median 3.1, range 3.1-155.6 pg/mL, p < 0.05). Interestingly, the BALF levels of CCL1 in the sarcoidosis patients (median 13.1, range 0.1-106.9 pg/mL) were significantly higher than those of the IgG4-RRD patients (median 9.8, range 0.1-14.7 pg/mL, p < 0.05). Furthermore, the CCL1 levels in the BALF were correlated with the total cell count (ρ = 0.539, p < 0.001), lymphocyte fraction (R = 0.406, P < 0.05), lymphocyte count (R = 0.686, P < 0.001), TNF-α level, (R = 0.748, P < 0.001), and IL-2 level (R = 0.757, P < 0.001) in the BALF of sarcoidosis patients., Conclusions: CCL1 might reflect disease activity and its involvement in the pathogenesis of sarcoidosis might be more closely related to Th1 than to Th2., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Cancer-associated fibroblasts (CAFs) activated by cancer cells has a central role in development and malignant biological behavior in colorectal cancer (CRC). Adult fibroblasts do not express Snail, but Snail-positive fibroblasts are discovered in the stroma of malignant CRC and reported to be the key role to chemoresistance. However, the reciprocal effect of CAFs expressed Snail to chemoresistance on CRC cells and the underlying molecular mechanisms are not fully characterized., Materials and Methods: Snail-overexpressed 3T3 stable cell lines were generated by lipidosome and CT26 mixed with 3T3-Snail subcutaneous transplanted CRC models were established by subcutaneous injection. Cell Counting Kit-8, flow cytometry and western blotting assays were performed, and immunohistochemistry staining was studied. The cytokines participated in chemoresistance was validated with reverse transcriptase-polymerase chain reaction and heatmap., Results: Snail-expression fibroblasts are discovered in human and mouse spontaneous CRCs. Overexpression of Snail induces 3T3 fibroblasts transdifferentiation to CAFs. CT26 co-cultured with 3T3-Snail resisted the impairment from 5-fluorouracil and paclitaxel in vitro. The subcutaneous transplanted tumor models included 3T3-Snail cells develop without restrictions even after treating with 5-fluorouracil or paclitaxel. Moreover, these chemoresistant processes may be mediated by CCL1 secreted by Snail-expression fibroblasts via transforming growth factor β/nuclear factor-κB signaling pathways., Conclusion: Taken together, Snail-expressing 3T3 fibroblasts display CAFs properties that support 5-fluorouracil and paclitaxel chemoresistance in CRC via participation of CCL1 and suggest that inhibition of the Snail-expression fibroblasts in tumor may be a useful strategy to limit chemoresistance.

PPARγ belongs to the group of nuclear receptors which is expressed in the trophoblast and together with other factors is responsible for the maintenance of pregnancy. Apart from that PPARγ is also a main factor for macrophage polarization. The aim of this study was to investigate the combined expression pattern and frequency of PPARγ under physiological circumstances and in spontaneous and recurrent miscarriages in the trophoblast and in maternal macrophages of the decidua. Human placental tissues of the first trimester (15 physiologic pregnancies, 15 spontaneous abortion and 16 recurrent miscarriage placentas) were analyzed for expression of the nuclear receptor PPARγ. Expression changes were evaluated by immunohistochemistry and real time PCR (RT-PCR) in trophoblast and in maternal macrophages of the decidua. Maternal macrophages were identified by double immunofluorescence using cluster of differentiation 68 (CD68) as marker for macrophages and further characterized regarding their M1/M2 polarization status. The intermediate villous trophoblast revealed a significantly lower PPARγ expression in spontaneous and recurrent abortion. Maternal macrophages express PPARγ. Their number is significantly enhanced in the decidua of spontaneous miscarriages whereas in recurrent miscarriages maternal macrophages seem to express PPARγ only in very few cases. PPARγ is associated with an M2 polarization state that is common for decidual macrophages. The lack of PPARγ in recurrent miscarriage decidual macrophages seems to be associated with a specific inflammatory response against the fetus.

Background/purpose: Asthma is a chronic airway inflammatory disease mediated by T-helper (Th)2 cells. Montelukast (trade name Singulair) is a cysteinyl leukotriene receptor antagonist used for asthma treatment. Mirroring Th1-Th2 polarization, two distinct states of macrophages have been recognized: the classically activated (M1) macrophages and the alternatively activated (M2) macrophages. M2 polarization is known to be a response to the Th2 cytokines; however, the effects of montelukast on M2 macrophages have not been well characterized. The aim of the present study was to investigate the effects of montelukast on the expression of cytokines and chemokines in M2-like macrophages, and to explore possible intracellular signaling pathways., Methods: The human monocytic leukemia cell line THP-1 and human monocytes from healthy donors were cultured with interleukin-4 for M2 polarization, and then the cells were pretreated with or without montelukast before lipopolysaccharide (LPS) stimulation. Supernatants were collected to determine interleukin-10, I-309/CCL1, and MDC/CCL22 levels by enzyme-linked immunosorbent assay. Intracellular signaling was investigated using nuclear factor (NF)-κB inhibitors, mitogen-activated protein kinase (MAPK) inhibitors, and western blot analysis., Results: LPS-induced interleukin-10 and I-309/CCL1 expression was significantly suppressed by montelukast in THP-1-derived and human monocyte-derived M2 macrophages after LPS stimulation. MDC/CCL22 expression was only significantly suppressed by montelukast in THP-1-derived M2 macrophages after 48 hours of incubation. In western blot analysis, montelukast was able to suppress LPS-induced MAPK-phospho-p38 and NF-κB-phospho-p65 expression., Conclusion: Montelukast suppressed LPS-induced M2-related cytokines and chemokines in alternatively activated macrophages, and the effects might be mediated through the MAPK-p38 and NF-κB-p65 pathways., (Copyright © 2016. Published by Elsevier B.V.)

Background: Chemokine (C-C motif) ligand 1 (CCL1) is produced by activated monocytes/ macrophages and T-lymphocytes, and acts as a potent attractant for Th2 cells and a subset of T-regulatory (Treg) cells. Previous reports have indicated that CCL1 is overexpressed in adult T-cell leukemia cells, mediating an autocrine anti-apoptotic loop. Because CCL1 is also known as a potent chemoattractant that plays a major role in inflammatory processes, we investigated the role of CCL1 in the pathogenesis of human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP)., Results: The results showed that: (1) CCL1 was preferentially expressed in HAM/TSP-derived HTLV-1-infected T-cell lines, (2) CCL1 expression was induced along with Tax expression in the Tax-inducible T-cell line JPX9, (3) transient Tax expression in an HTLV-1-negative T-cell line activated the CCL1 gene promoter, (4) plasma levels of CCL1 were significantly higher in patients with HAM/TSP than in HTLV-1-seronegative patients with multiple sclerosis and HTLV-1-infected asymptomatic healthy carriers, and (5) minocycline inhibited the production of CCL1 in HTLV-1-infected T-cell lines., Conclusions: The present results suggest that elevated CCL1 levels may be associated with the pathogenesis of HAM/TSP. Although further studies are required to determine the in vivo significance, minocycline may be considered as a potential candidate for the long-term treatment of HAM/TSP via its anti-inflammatory effects, which includes the inhibition of CCL1 expression.

As an important component of the tumor microenvironment, CD4 + CD25 + Tregs reduce antitumor immunity, promote angiogenesis and metastasis in breast cancer. However, their function in regulating the "stemness" of tumor cells and the communication between Tregs and cancer stem cells (CSCs) remain elusive. Here, we disclose that the primarily cultured Tregs isolated from breast-tumor-bearing Foxp3-EGFP mouse upregulate the stemness property of breast cancer cells. Tregs increased the side-population and the Aldehyde dehydrogenase-bright population of mouse breast cancer cells, promoted their sphere formation in a paracrine manner, and enhanced the expression of stemness genes, such as Sox2 and so forth. In addition, Tregs increased tumorigenesis, metastasis, and chemoresistance of breast cancer cells. Furthermore, Sox2-overexpression tumor cells activated NF-κB-CCL1 signaling to recruit Tregs through reducing the binding of H3K27Me3 on promoter regions of p65 and Ccl1. These findings reveal the functional interaction between Tregs and CSCs and indicate that targeting on the communication between them is a promising strategy in breast cancer therapy. Stem Cells 2017;35:2351-2365., (© 2017 AlphaMed Press.)

Background: Hepatitis viruses are non-cytopathic viruses that lead to the infection and pathogenesis of liver diseases as a result of immunologically mediated events., Objective: To investigate the expression of human inflammatory cytokines in chronic hepatitis B patients according to the severity of the infection., Methods: We recruited a total of 120 patients, 40 of whom from cirrhotic, 40 non-cirrhotic, and 40 acute flare chronic hepatitis B and 40 healthy controls. For all groups total cellular RNA was extracted from whole blood samples, genomic DNA was eliminated, and cDNA was synthesized using the RT2 first strand kit, as instructed by the manufacturer. The real-time profiler PCR array was performed on a master cycler ep realplex and the data were analyzed using an online data analysis software., Results: Non-cirrhotic chronic hepatitis B patients were found to significantly upregulate interleukin 10 receptors that regulate the balance between T helpers 1 and 2. On the other hand, patients with cirrhosis were found to have significant upregulated interleukin 3 gene expression., Conclusion: Our finding suggests that upregulation of anti-inflammatory and downregulation of pro-inflammatory cytokines may play a role in the progression of non-cirrhotic chronic hepatitis B patients to cirrhotic and acute flare. However, a multi-center study with a larger sample size is needed to confirm our findings.

Background: Chemokine signaling has been implicated in the pathogenesis of diabetic neuropathy; however, the involvement of the chemokine CC motif ligand 1 (CCL1)-chemokine CC motif receptor 8 (CCR8) interaction remains unknown. The goal of this study was to examine the role of CCL1-CCR8 signaling interplay in the development of hypersensitivity and in opioid effectiveness in diabetic neuropathy., Methods: Primary glial cell cultures and a streptozotocin (STZ; 200mg/kg, intraperitoneal)-induced mouse model of diabetic neuropathy were used. Analysis of mRNA/protein expression of glial markers and CCL1/CCR8 was performed by qRT-PCR, Western blotting and/or protein arrays. The co-localization of CCL1/CCR8 with neural/glial cells was visualized by immunofluorescence. The pharmacological tools were injected intrathecally, and pain behavior was evaluated by von Frey/cold plate tests., Results: Single STZ injection increased blood glucose levels and induced the development of hypersensitivity as measured on days 7-21. On day 7 after STZ, the protein levels of CCL1 and IBA1 but not of CCR8 or GFAP were elevated. Immunofluorescent staining revealed that CCR8 was predominantly localized in neurons, which are also the main source of spinal CCL1. Lipopolysaccharide stimulation of primary microglial cultures resulted in decreases in the levels of CCL1 and CCR8. Single intrathecal injection of CCL1 (10-500ng) induced the development of hypersensitivity, whereas on day 7 after STZ, a CCL1-neutralizing antibody dose-dependently (2-8μg) delayed pain behavior. Repeated administration of the CCL1-neutralizing antibody (4μg) also enhanced the effectiveness of morphine and buprenorphine (1μg)., Conclusion: These results reveal that CCL1/CCR8 neuronal signaling plays an important role in the development of diabetic neuropathy and the effectiveness of opioids., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Many chemokines expressed by cells of the uterine endometrium of mammals are involved in cell-cell interactions. However, little is known about expression and functional roles of chemokine (C-C motif) ligand 23 (CCL23) in the uterine endometrium. Results of this study demonstrated that CCL23 and its receptor, chemokine (C-C motif) receptor type 1 (CCR1), are up-regulated in porcine endometria during pregnancy. CCL23 and CCR1 mRNAs were strongly expressed in endometrial glandular (GE) and luminal (LE) epithelial cells. Treatment of porcine uterine luminal epithelial (pLE) cells with recombinant CCL23 increased the abundances of PCNA and cyclin D1, and enhanced proliferation and cell cycle progression in pLE cells. CCL23 also stimulated phosphorylation of cell signaling molecules including AKT and MAPKs in pLE cells. Furthermore, ER stress-related molecules were reduced by CCL23. These results suggest that CCL23-CCR1 signaling is important for endometrial development and establishment of pregnancy in pigs., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The current study identifies CCR8 + regulatory T cells (T reg cells) as drivers of immunosuppression. We show that in human peripheral blood cells, more than 30% of T reg up-regulate CCR8 following activation in the presence of CCL1. This interaction induces STAT3-dependent up-regulation of FOXp3, CD39, IL-10, and granzyme B, resulting in enhanced suppressive activity of these cells. Of the four human CCR8 ligands, CCL1 is unique in potentiating T reg cells. The relevance of these observations has been extended using an experimental model of multiple sclerosis [experimental autoimmune encephalomyelitis, (EAE)] and a stabilized version of mouse CCL1 (CCL1-Ig). First, we identified a self-feeding mechanism by which CCL1 produced by T reg cells at an autoimmune site up-regulates the expression of its own receptor, CCR8, on these cells. Administration of CCL1-Ig during EAE enhanced the in vivo proliferation of these CCR8 + regulatory cells while inducing the expression of CD39, granzyme B, and IL-10, resulting in the efficacious suppression of ongoing EAE. The critical role of the CCL1-CCR8 axis in T reg cells was further dissected through adoptive transfer studies using CCR8 -/- mice. Collectively, we demonstrate the pivotal role of CCR8 + T reg cells in restraining immunity and highlight the potential clinical implications of this discovery., Competing Interests: Conflict of interest statement: N.K., Y.B., and G.W. hold a pending patent on CCL1-based therapy of autoimmunity and graft-versus-host disease that has been outlicensed to GlaxoSmithKline.

Mortality associated with Staphylococcus aureus infection remains high during the sub-acute phase of burn injury. In this study, we aimed to improve antibacterial resistance of sub-acutely burned mice through macrophage polarization. Sepsis did not develop in mice at the sub-acute phase of 5% total body surface area (TBSA) burn after being infected with methicillin-resistant S. aureus (MRSA), and M1 macrophages (interleukin (IL)-10 - IL-12 + inducible nitric oxide synthase + Mφ) were isolated from these mice. In contrast, predominantly M2b macrophages (C-C motif chemokine ligand 1 (CCL1) + IL-10 + IL-12 - Mφ) were isolated from mice with >15% TBSA burn, and all of these mice died after the same MRSA infection. Comparing NOD scid gamma mice inoculated with Mφ with 25% TBSA burns, all mice treated with CCL1 antisense oligodeoxynucleotide (ODN) survived after MRSA infection, whereas all untreated mice given the same infection died within 4 days. CCL1 antisense ODN has been characterized as a specific polarizer of M2bMφ. M1Mφ were isolated from MRSA-infected mice with 25% TBSA burn after treatment with CCL1 antisense ODN, and these mice were shown to be resistant against a lethal dose of MRSA infection. M1Mφ were also isolated from 25% TBSA-burned mice infected with MRSA when the ODN was administered therapeutically, and subsequent sepsis was effectively controlled in these mice. These results indicate that the M2bMφ polarizer is beneficial for controlling MRSA infection in mice at the sub-acute phase of severe burn injury.

Introduction: Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are smoking-related diseases, with the presence of COPD itself increasing the risk for development of LC, probably owing to underlying inflammation. LC is typically detected at late stages of the disease and carries a poor prognosis. There is an unmet need for methods to facilitate the early detection of LC in high-risk subjects such as smokers., Methods: The expression of inflammatory proteins in bronchoalveolar lavage fluid (BALF) samples was studied by antibody arrays in a prospective cohort of 60 smokers of more than 30 pack-years divided into four groups (control, patients with LC, patients with COPD, and patients with LC plus COPD). Relevant biomarkers were validated by Western blot. Additional validation with enzyme-linked immunosorbent assay (ELISA) was carried out on two independent controlled cohorts of 139 patients (control, patients with LC, patients with COPD, and patients with LC plus COPD) and 160 patients (control and patients with LC of all histological types)., Results: A total of 16 differentially expressed proteins in samples from patients with LC, COPD, and LC plus COPD were identified by antibody arrays and validated by Western blot and ELISA. C-C motif chemokine ligand 1 (CCL-1) and interleukin-11 (IL)-11 were selectively expressed in samples from patients with adenocarcinoma with or without COPD (p < 0.005). These proteins exhibited a remarkable diagnostic performance for lung adenocarcinoma in an independent cohort of 139 patients. Receiver operating characteristic curves showed that the optimum diagnostic cutoff value for IL-11 was 42 pg/mL (area under the curve = 0.93 [95% confidence interval: 0.896-0.975], sensitivity 90%, specificity 86%), whereas for CCL-1 it was 39.5 pg/mL (0.83 [95% confidence interval: 0.749-0.902], sensitivity 83%, and specificity 74%). Further validation of the ELISA biomarkers at the aforementioned cutoffs was performed in an additional cohort of 160 patients (20 controls, 66 patients with LC, and 74 patients with LC plus COPD). There was a significant correlation between BALF levels of IL-11 and CCL-1 (r 2  = 0.76, p < 0.001), and the use of both biomarkers increased the diagnostic accuracy to 96.1% in the two validation cohorts. Appropriate diagnostic performance was observed for all subgroups regardless of stage at diagnosis, involvement of the bronchial tract, pack-years smoked, and number of cells in BALF., Conclusions: IL-11 and CCL-1 are highly specific biomarkers with great accuracy for the diagnosis of lung adenocarcinoma in BALF specimens. Further study of these proteins as markers for the early diagnosis and screening of plasma and other biological materials is warranted., (Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Chemokine receptors play important roles in the immune system and are linked to several human diseases. The initial contact of chemokines with their receptors depends on highly specified extracellular receptor features. Here we investigate the importance of conserved extracellular disulfide bridges and aromatic residues in extracellular loop 2 (ECL-2) for ligand binding and activation in the chemokine receptor CCR8. We used inositol 1,4,5-trisphosphate accumulation and radioligand binding experiments to determine the impact of receptor mutagenesis on both chemokine and small molecule agonist and antagonist binding and action in CCR8. We find that the seven-transmembrane (TM) receptor conserved disulfide bridge (7TM bridge) linking transmembrane helix III (TMIII) and ECL-2 is crucial for chemokine and small molecule action, whereas the chemokine receptor conserved disulfide bridge between the N terminus and TMVII is needed only for chemokines. Furthermore, we find that two distinct aromatic residues in ECL-2, Tyr(184) (Cys + 1) and Tyr(187) (Cys + 4), are crucial for binding of the CC chemokines CCL1 (agonist) and MC148 (antagonist), respectively, but not for small molecule binding. Finally, using in silico modeling, we predict an aromatic cluster of interaction partners for Tyr(187) in TMIV (Phe(171)) and TMV (Trp(194)). We show in vitro that these residues are crucial for the binding and action of MC148, thus supporting their participation in an aromatic cluster with Tyr(187) This aromatic cluster appears to be present in a large number of CC chemokine receptors and thereby could play a more general role to be exploited in future drug development targeting these receptors., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

Background: Calcineurin inhibitors (CNIs) exhibit remarkable efficacy in atopic dermatitis (AD). Tacrolimus, one type of CNI, is prevalently used to treat AD. AD is a chronic inflammatory disease that exhibits predominant infiltration of T-helper type 2 (Th2) cell in the acute phase and a mixed Th1 and Th0 cell pattern in chronic lesions. Cytokines such as tumor necrosis factor-α (TNF-α), Th2-related chemokines [e.g., macrophage-derived chemokine (MDC)/CCL22 and I-309/CCL1], Th1-related chemokines [e.g., interferon γ-induced protein 10 (IP-10)/CXCL10], and neutrophil chemoattractant growth-related oncogene-α (GRO-α)/CXCL1 are involved in the pathogenesis of AD. However, whether tacrolimus modulates the expression of AD-associated cytokines and chemokines remains unknown. The intracellular mechanisms of tacrolimus are also unclear., Methods: Human monocytic cell line THP-1 cells were pretreated with tacrolimus and stimulated with lipopolysaccharide (LPS). The MDC, I-309, IP-10, GRO-α, and TNF-α concentrations of the cell supernatants were measured using enzyme-linked immunosorbent assay. Intracellular signaling was investigated using the Western blot analysis., Results: Tacrolimus suppressed the expression of MDC, IP-10, I-309, GRO-α, and TNF-α in LPS-stimulated THP-1 cells in a dose- and time-dependent manner. All three mitogen-activated protein kinase (MAPK) inhibitors and the nuclear factor-κB inhibitor suppressed LPS-induced MDC, I-309, and TNF-α expressions in THP-1 cells. Only MAPK inhibitors suppressed LPS-induced expression of IP-10 and GRO-α. Tacrolimus suppressed the LPS-induced phosphorylation of MAPK-extracellular signal-related kinase (ERK)., Conclusion: Tacrolimus suppressed LPS-induced MDC, I-309, IP-10, GRO-α, and TNF-α expressions in monocytes through the MAPK-ERK pathway; thus, tacrolimus may yield therapeutic efficacy by modulating AD-associated cytokines and chemokines., (Copyright © 2014. Published by Elsevier B.V.)

Long non‑coding RNAs (lncRNAs) have important roles in diverse biological processes, including transcriptional regulation, cell growth and tumorigenesis. The present study aimed to investigate whether lncRNA‑growth arrest‑specific (GAS)5 regulated bladder cancer progression via regulation of chemokine (C‑C) ligand (CCL)1 expression. The viability of BLX bladder cancer cells was detected using a Cell Counting kit‑8 assay, and cell apoptosis was assessed by annexin V‑propidium iodide double‑staining. The expression levels of specific genes and proteins were analyzed by reverse transcription‑quantitative polymerase chain reaction and western blotting, respectively. In addition, cells were transfected with small interfering (si)RNAs or recombinant GAS5 in order to silence or overexpress GAS5, respectively. The results of the present study demonstrated that knockdown of GAS5 expression promoted bladder cancer cell proliferation, whereas overexpression of GAS5 suppressed cell proliferation. Furthermore, knockdown of GAS5 resulted in an increased percentage of cells in S and G2 phase, and a decreased percentage of cells in G1 phase. In addition, the present study performed a hierarchical cluster analysis of differentially expressed lncRNAs in bladder cancer cells and detected that CCL1 overexpression resulted in an upregulation of GAS5, which may improve the ability of cells to regulate a stress response in vitro. Furthermore, knockdown of GAS5 expression increased the mRNA and protein expression of CCL1 in bladder cancer cells. Gain‑of‑function and loss‑of‑function studies demonstrated that GAS5 was able to inhibit bladder cancer cell proliferation, at least in part, by suppressing the expression of CCL1. The results of the present study demonstrated that GAS5 was able to suppress bladder cancer cell proliferation, at least partially, by suppressing the expression of CCL1. The results of the present study may provide a basis for developing novel effective treatment strategies against bladder cancer.

Lactoferrin (LF) exhibits a wide range of immunomodulatory activities including modulation of cytokine and chemokine secretion. In this study, we demonstrate that bovine LF (bLF) up-modulates, in a concentration- and time-dependent manner, CCL1 secretion in monocytes (Mo) at the early stage of differentiation toward dendritic cells (DCs), and in fully differentiated immature Mo-derived DCs (MoDCs). In both cell types, up-modulation of CCL1 secretion is an early event following bLF-mediated enhanced accumulation of CCL1 transcripts. Notably, bLF-mediated up-regulation of CCL1 involves the engagement of distinct surface receptors in MoDCs and their Mo precursors. We show that bLF-mediated engagement of CD36 contributes to CCL1 induction in differentiating Mo. Conversely, toll-like receptor (TLR)2 blocking markedly reduces bLF-induced CCL1 production in MoDCs. These findings add further evidence for cell-specific differential responses elicited by bLF through the engagement of distinct TLRs and surface receptors. Furthermore, the different responses observed at early and late stages of Mo differentiation towards DCs may be relevant in mediating bLF effects in specific body districts, where these cell types may be differently represented in physiopathological conditions.

Inflammation in atopic dermatitis is mediated in part by the chemokine CCL1 and its receptor, CCR8. Recombinant Molluscum contagiosum viral protein (rMC148p), a cc-chemokine homolog, inhibits CCL1-induced chemotaxis of cells expressing CCR8. rMC148p was prepared using the baculovirus/Sf9 insect cell expression system. The recombinant MC148 fusion protein (rMC148fp), rMC148-TAT-6xHis, was similarly prepared by adding base sequences onto the PCR primers to fuse TAT and 6xHis to rMC148p at the carboxyl terminus. rMC148fp retains the capacity of rMC148p to inhibit CCL1-induced chemotaxis. Furthermore, unlike rMC148p, topically applied rMC148fp penetrates stratum corneum of human neonatal foreskins and concentrates along the basal and lower spinous cell layers of the epidermis. rMC148fp may be a safe and effective agent in the treatment of atopic dermatitis and other CCR8-mediated disorders.

We studied the pathogenesis and transmissibility of a novel avian-origin H7N9 influenza virus in pigs. When pigs were infected with H7N9 influenza virus, they did not show any clear clinical signs (such as sneezing, fever and loss of body weight), and they shed viruses through their noses for 2 days after infection. No transmission occurred between infected and naïve pigs. Pigs suffered from mild pneumonia, which was accompanied by the induction of inflammatory cytokines and chemokines such as IL-8 and CCL1. Taken together, our results suggest that pigs may not play an active role in transmitting H7N9 influenza virus to mammals.

Recent clinical trials in patients with inflammatory diseases like multiple sclerosis (MS) or inflammatory bowel disease (IBD) have shown the beneficial effects of probiotic helminth administration, although the underlying mechanism of action remains largely unknown. Potential cellular targets may include innate immune cells that propagate inflammation in these diseases, like pro-inflammatory macrophages. We here investigated the effects of the helminth Trichuris suis soluble products (SPs) on the phenotype and function of human inflammatory (granulocyte-macrophage colony-stimulating factor (GM-CSF)-differentiated) macrophages. Interestingly, we here show that T. suis SPs potently skew inflammatory macrophages into a more anti-inflammatory state in a Toll-like receptor 4 (TLR4)-dependent manner, and less effects are seen when stimulating macrophages with TLR2 or -3 ligands. Gene microarray analysis of GM-CSF-differentiated macrophages further revealed that many TLR4-induced inflammatory mediators, including interleukin (IL)-12B, CCL1 and CXCL9, are downregulated by T. suis SPs. In particular, we observed a strong reduction in the expression and function of P2RX7, a purinergic receptor involved in macrophage inflammation, leading to reduced IL-1β secretion. In conclusion, we show that T. suis SPs suppress a broad range of inflammatory pathways in GM-CSF-differentiated macrophages in a TLR4-dependent manner, thereby providing enhanced mechanistic insight into the therapeutic potential of this helminth for patients with inflammatory diseases.

Background & Objectives: Selective cyclooxygenase-2 (COX-2) inhibitor is a form of thnon steroidal anti-inflammatory drug (NSAID) and is commonly used in autoimmune and rheumatic diseases to control inflammation and alleviate pain. Tumour necrosis factor-alpha (TNF-α) production and an imbalance of T helper 1 (Th1)/Th2 contribute to the pathogenesis of autoimmune and also anti-tumour activity. Dipyrone is a NSAID used to treat pain worldwide. The celecoxib analogue, 2,5-dimethylcelecoxib (DMC), lacks COX-2 inhibitory activity but exhibits anti-tumour properties. However, the effects and the mechanisms of dipyrone and 2,5-dimethylcelecoxib on tumour necrosis factor (TNF)-α and Th1- and Th2-related chemokines in monocytes remain poorly defined. This study was carried out to investigate the effects of dipyrone and 2,5-dimethylcelecoxib on the expression of Th1 (IP-10) and Th2 (I-309 and MDC) and TNF-α in human monocytes and the associated intracellular mechanism., Methods: THP-1 cells and peripheral blood mononuclear cells (PBMCs) were pre-treated with dipyrone (10(-9)-10(-4) M) and 2,5-dimethylcelecoxib (10(-9)-10(-5) M) 2 h before lipopolysaccharide (LPS) stimulation. Cell supernatant was collected 24 h after LPS stimulation. TNF-α, I-309, MDC and IP-10 concentrations of cell supernatants were determined using ELISA. Intracellular signaling was evaluated by w0 estern blot., Results: Dipyrone and 2,5-dimethylcelecoxib downregulated LPS-induced Th2-related chemokine I-309 and macrophage derived chemokine (MDC) production. Only high dose of 2,5-dimethylcelecoxib (10(-5) M), but not dipyrone downregulated LPS-induced IP-10. Only very high dose of 2,5-dimethylcelecoxib had effect on LPS-induced TNF-α expression in PBMCs. Dipyrone and 2,5-dimethylcelecoxib suppressed LPS-induced p65 and JNK MAPK (C-Jun N-terminal kinase mitogen activated protein kinase). expression., Interpretation & Conclusions: Dipyrone and 2,5-dimethylcelecoxib downregulated LPS-induced Th2-related chemokine I-309 and MDC in THP-1 cells. The suppressive effect on Th2-related chemokine I-309 and MDC may involve the downregulation of LPS-induced JNK and p65 expression.

Pain control is very important since, even today, 20 million people suffer from neuropathic pain. Although many basic science and clinical researchers have made efforts to control pain, the mechanism of neuropathic pain is unfortunately still not fully understood. Morphine, a prototypical opioid, is a useful medicine to relieve severe pain. However, repeated or continuous use of morphine and other opioids are associated with a potential risk of analgesic tolerance, which requires an increase in dosage to maintain the same efficacy. In addition, morphine is not always effective in neuropathic pain. In this review we focus on: (1) the role of muscarinic receptors in the spinal cord and anterior cingulate cortex (ACC) in neuropathic pain, (2) how chemokine (C-C motif) ligand 1 (CCL-1) is involved in neuropathic pain, and (3) the novel mechanism of morphine tolerance. The findings in this study may cast new light on novel mechanism of neuropathic pain and development of novel clinical medicines in the future.

Studies have indicated increased incidence and severity of allergic asthma due to western lifestyle and increased sedentary activity. Investigations also indicate that exercise reduces the severity of asthma; however, a mechanism of action has not been elucidated. Additional work implicates re-distribution of T helper (Th) cells in mediating alterations of the immune system as a result of moderate aerobic exercise in vivo. We have previously reported that exercise decreases T helper 2 (Th2) responses within the lungs of an ovalbumin (OVA)-sensitized murine allergic asthma model. Therefore, we hypothesized that exercise alters the migration of OVA-specific Th cells in an OVA-challenged lung. To test this hypothesis, wildtype mice received OVA-specific Th cells expressing a luciferase-reporter construct and were OVA-sensitized and exercised. OVA-specific Th cell migration was decreased in OVA-challenged lungs of exercised mice when compared to their sedentary controls. Surface expression levels of lung-homing chemokine receptors, CCR4 and CCR8, on Th cells and their cognate lung-homing chemokine gradients revealed no difference between exercised and sedentary OVA-sensitized mice. However, transwell migration experiments demonstrated that lung-derived Th cells from exercised OVA-sensitized mice exhibited decreased migratory function versus controls. These data suggest that Th cells from exercised mice are less responsive to lung-homing chemokine. Together, these studies demonstrate that moderate aerobic exercise training can reduce the accumulation of antigen-specific Th cell migration into an asthmatic lung by decreasing chemokine receptor function., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Lymphatic vessels are thought to contribute to metastasis primarily by serving as a transportation system. It is widely believed that tumor cells enter lymph nodes passively by the flow of lymph. We demonstrate that lymph node lymphatic sinuses control tumor cell entry into the lymph node, which requires active tumor cell migration. In human and mouse tissues, CCL1 protein is detected in lymph node lymphatic sinuses but not in the peripheral lymphatics. CCR8, the receptor for CCL1, is strongly expressed by human malignant melanoma. Tumor cell migration to lymphatic endothelial cells (LECs) in vitro is inhibited by blocking CCR8 or CCL1, and recombinant CCL1 promotes migration of CCR8(+) tumor cells. The proinflammatory mediators TNF, IL-1β, and LPS increase CCL1 production by LECs and tumor cell migration to LECs. In a mouse model, blocking CCR8 with the soluble antagonist or knockdown with shRNA significantly decreased lymph node metastasis. Notably, inhibition of CCR8 led to the arrest of tumor cells in the collecting lymphatic vessels at the junction with the lymph node subcapsular sinus. These data identify a novel function for CCL1-CCR8 in metastasis and lymph node LECs as a critical checkpoint for the entry of metastases into the lymph nodes.

Microglia, which constitute the resident macrophages of the central nervous system (CNS), are generally considered as the primary immune cells in the brain and spinal cord. Microglial cells respond to various factors which are produced following nerve injury of multiple aetiologies and contribute to the development of neuronal disease. Chemokine (C-C motif) ligand 1 (CCL-1), a well-characterized chemokine secreted by activated T cells, has been shown to play an important role in neuropathic pain induced by nerve injury and is also produced in various cell types in the CNS, especially in dorsal root ganglia (DRG). However, the role of CCL-1 in the CNS and the effects on microglia remains unclear. Here we showed the multiple effects of CCL-1 on microglia. We first showed that CCR-8, a specific receptor for CCL-1, was expressed on primary cultured microglia, as well as on astrocytes and neurons, and was upregulated in the presence of CCL-1. CCL-1 at concentration of 1 ng/ml induced chemotaxis, increased motility at a higher concentration (100 ng/ml), and increased proliferation and phagocytosis of cultured microglia. CCL-1 also activated microglia morphologically, promoted mRNA levels for brain-derived neurotrophic factor (BDNF) and IL-6, and increased the release of nitrite from microglia. These indicate that CCL-1 has a role as a mediator in neuron-glia interaction, which may contribute to the development of neurological diseases, especially in neuropathic pain., (Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.)

In several malignant tumors including lymphoma, macrophages that infiltrate tumor tissues are called tumor-associated macrophages (TAMs). We discovered that TAMs, especially the CD163⁺ alternatively activated phenotype (M2), were closely involved with progression of adult T-cell leukemia/lymphoma (ATLL). We used CD68 (a pan-macrophage marker) and CD163 (an M2 marker) to immunostain 58 ATLL samples. Statistical analyses showed that a high number of CD68⁺ TAMs and an increased percentage of CD163⁺ cells among the TAMs were associated with a worse clinical prognosis; multivariate analysis indicated that the percentage of CD163⁺ cells was an independent prognostic factor. We also carried out in vitro coculture experiments with ATLL cell lines (ATN-1 and TL-Mor) and monocyte-derived macrophages and found that direct coculture with M2 macrophages significantly increased BrdU incorporation into ATLL cell lines. A cytokine array analysis showed that macrophage-derived soluble factors including C5a, tumor necrosis factor-α, growth-related oncogene-α, CCL1/I-309, and interleukin-6 stimulated ATLL cell lines. CD163 expression in macrophages was strongly induced by direct contact with ATN-1 cells, and downregulation of CD163 in macrophages significantly suppressed growth of cocultured ATN-1 cells. These results suggest that interaction between M2 macrophages and lymphoma cells may be an appropriate target in treatment of patients with ATLL., (© 2013 Japanese Cancer Association.)

Stromal chemokine gradients within the breast tissue microenvironment play a critical role in breast cancer cell invasion, a prerequisite to metastasis. To elucidate which chemokines and mechanisms are involved in mammary cell migration we determined whether mesenchymal D1 stem cells secreted specific chemokines that differentially promoted the invasion of mammary tumor cells in vitro. Results indicate that mesenchymal D1 cells produced concentrations of CCL5 and CCL9 4- to 5-fold higher than the concentrations secreted by 4T1 tumor cells (P < 0.01). Moreover, 4T1 tumor cell invasion toward D1 mesenchymal stem cell conditioned media (D1CM), CCL5 alone, CCL9 alone or a combination CCL5 and CCL9 was observed. The invasion of 4T1 cells toward D1 mesenchymal stem CM was dose-dependently suppressed by pre-incubation with the CCR1/CCR5 antagonist met-CCL5 (P < 0.01). Furthermore, the invasion of 4T1 cells toward these chemokines was prevented by incubation with the broad-spectrum MMP inhibitor GM6001. Additionally, the addition of specific MMP9/MMP13 and MMP14 inhibitors prevented the MMP activities of supernatants collected from 4T1 cells incubated with D1CM, CCL5 or CCL9. Taken together these data highlight the role of CCL5 and CCL9 produced by mesenchymal stem cells in mammary tumor cell invasion.

Purpose: Chemokines are involved in cancer-related inflammation and malignant progression. In this study, we evaluated expression of CCR8 and its natural cognate ligand CCL1 in patients with urothelial carcinomas of bladder and renal cell carcinomas., Experimental Design: We examined CCR8 expression in peripheral blood and tumor tissues from patients with bladder and renal carcinomas. CCR8-positive myeloid cells were isolated from cancer tissues with magnetic beads and tested in vitro for cytokine production and ability to modulate T-cell function., Results: We show that monocytic and granulocytic myeloid cell subsets in peripheral blood of patients with cancer with urothelial and renal carcinomas display increased expression of chemokine receptor CCR8. Upregulated expression of CCR8 is also detected within human cancer tissues and primarily limited to tumor-associated macrophages. When isolated, CD11b(+)CCR8(+) cell subset produces the highest levels of proinflammatory and proangiogenic factors among intratumoral CD11b myeloid cells. Tumor-infiltrating CD11b(+)CCR8(+) cells selectively display activated Stat3 and are capable of inducing FoxP3 expression in autologous T lymphocytes. Primary human tumors produce substantial amounts of the natural CCR8 ligand CCL1., Conclusions: This study provides the first evidence that CCR8(+) myeloid cell subset is expanded in patients with cancer. Elevated secretion of CCL1 by tumors and increased presence of CCR8(+) myeloid cells in peripheral blood and cancer tissues indicate that CCL1/CCR8 axis is a component of cancer-related inflammation and may contribute to immune evasion. Obtained results also implicate that blockade of CCR8 signals may provide an attractive strategy for therapeutic intervention in human urothelial and renal cancers., (©2013 AACR.)

Background and Purpose: Here we present a novel series of CCR8 antagonists based on a naphthalene-sulfonamide structure. This structure differs from the predominant pharmacophore for most small-molecule CC-chemokine receptor antagonists, which in fact activate CCR8, suggesting that CCR8 inhibition requires alternative structural probes., Experimental Approach: The compounds were tested as inverse agonists and as antagonists against CCL1-induced activity in Gα(i) signalling and chemotaxis. Furthermore, they were assessed by heterologous competition binding against two radiolabelled receptor ligands: the endogenous agonist CCL1 and the virus-encoded antagonist MC148., Key Results: All compounds were highly potent inverse agonists with EC(50) values from 1.7 to 23 nM. Their potencies as antagonists were more widely spread (EC(50) values from 5.9 to 1572 nM). Some compounds were balanced antagonists/inverse agonists whereas others were predominantly inverse agonists with >100-fold lower potency as antagonists. A correspondingly broad range of affinities, which followed the antagonist potencies, was disclosed by competition with [(125)I]-CCL1 (K(i) 3.4-842 nM), whereas the affinities measured against [(125)I]-MC148 were less widely spread (K(i) 0.37-27 nM), and matched the inverse agonist potencies., Conclusion and Implications: Despite highly potent and direct effects as inverse agonists, competition-binding experiments against radiolabelled agonist and tests for antagonism revealed a probe-dependent allosteric effect of these compounds. Thus, minor chemical changes affected the ability to modify chemokine binding and action, and divided the compounds into two groups: predominantly inverse agonists and balanced antagonists/inverse agonists. These studies have important implications for the design of new inverse agonists with or without antagonist properties., (© 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.)

Although regulatory T cells (T(regs)) are known to suppress self-reactive autoimmune responses, their role during T cell responses to nonself antigens is not well understood. We show that T(regs) play a critical role during the priming of immune responses in mice. T(reg) depletion induced the activation and expansion of a population of low-avidity CD8(+) T cells because of overproduction of CCL-3/4/5 chemokines, which stabilized the interactions between antigen-presenting dendritic cells and low-avidity T cells. In the absence of T(regs), the avidity of the primary immune response was impaired, which resulted in reduced memory to Listeria monocytogenes. These results suggest that T(regs) are important regulators of the homeostasis of CD8(+) T cell priming and play a critical role in the induction of high-avidity primary responses and effective memory.

Background: Recent studies have shown that chemoattractive proteins play an important role in the organization of the innate and adaptive immune responses. There are some reports that chemokine (C-C motif) ligand (CCL)1 and CCL18, members of a family of chemoattractive proteins, have increased expression in atopic dermatitis (AD)., Aim: To evaluate the quantity and pattern of CCL1 and CCL18 expression in lesions and blood of patients with AD, and compare them with those of patients with psoriasis., Methods: Biopsy specimens were taken from atopic skin and normal-appearing skin of patients with AD and from the psoriatic skin only of patients with psoriasis. Quantitative real-time PCR analysis and immunohistochemistry of CCL1 and CCL18 expression were performed, and the quantities of expressed CCL1 and CCL18 in acute AD were compared with those of normal-appearing atopic skin and psoriatic skin. The serum level of CCL1 and CCL18 was assessed by ELISA., Results: Expression of CCL1 mRNA and protein was significantly higher in the acute lesional skin of patients with AD than in their nonlesional skin or in the lesional skin of patients with psoriasis. Both CCL18 mRNA and protein were abundant in acute AD lesions and in psoriatic lesions, but were lower in the nonlesional skin of patients with AD. The serum levels of CCL1 and CCL18 were not different in patients with AD and patients with psoriasis., Conclusions: CCL1 is a chemokine that is associated with AD. Both CCL1 and CCL18 may play important roles in the initiation and progression of atopic skin inflammation., (© The Author(s). CED © 2012 British Association of Dermatologists.)