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Query: UMLS:C1852438 (CCL)
 1,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemokines interact with specific G-protein-coupled cell-surface receptors and with glycosaminoglycans (GAGs), such as heparan sulphate. Although chemokines often form multimers in solution, this process may be enhanced following interaction with GAGs on the cell surface, or within the extracellular matrix. However, the significance of multimerization for chemokine function remains controversial. In the present study, a fusion protein was prepared between the prototypical human CC chemokine, monocyte chemoattractant protein-1 (MCP-1; also known as CCL-2) and a large secreted placental alkaline phosphatase (SEAP) moiety. This fusion protein (MCP-1-SEAP) remained monomeric under conditions that promote oligomerization of the native chemokine. Radioligand binding showed that both native MCP-1 and MCP-1-SEAP competed for the same site on the surface of HEK-293 cells expressing the CCR2b chemokine receptor. The interaction between either chemokine species and endothelial cell surface GAGs was antagonized by the addition of the heparan sulphate-like molecule, heparin. Both MCP-1 and MCP-1-SEAP induced a Ca(2+)-flux in the THP-1 monocytic cell line, and were equally effective at promoting transendothelial chemotaxis of mononuclear immune cells, with maximal migration being produced by treatment with 12 nM of either species. In each case this chemotactic response was almost completely antagonized by the addition of heparin. The importance of interaction between either native MCP-1 or MCP-1-SEAP and cell-surface GAGs for transcellular migration was demonstrated by the almost complete absence of leucocyte chemotaxis across monolayers of GAG-deficient mutant cells. In summary, this study shows that multimerization is neither necessary for, nor potentiates, the biological activity of MCP-1. However, the results do clearly demonstrate the importance of the interaction between MCP-1 and cell-surface heparan sulphate for transmonolayer leucocyte chemotaxis.
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PMID:Multimerization of monocyte chemoattractant protein-1 is not required for glycosaminoglycan-dependent transendothelial chemotaxis. 1153 34

We previously reported that chronic stimulation with low, noncytotoxic doses of extracellular adenosine triphosphate (ATP) induced a distorted maturation of dendritic cells (DCs) and impaired their capacity to initiate T-helper (Th) 1 responses in vitro. Here, we examined the effects of ATP on chemokine-receptor expression and chemokine production by DCs. ATP strongly induced expression of CXC chemokine receptor 4 on both immature and lipopolysaccharide (LPS)-stimulated DCs and slightly up-regulated CC chemokine receptor (CCR) 7 on both DC types. In contrast, ATP reduced CCR5 expression on immature DCs. These effects were confirmed at both the messenger RNA and protein levels and were not produced by uridine triphosphate (UTP). Consistent with the changed receptor expression, ATP increased migration and intracellular calcium of immature and mature DCs to stromal-derived factor 1 (CXC ligand [CXCL] 12) and macrophage inflammatory protein [MIP] 3 beta (CC ligand [CCL] 19), whereas responses to MIP-1 beta (CCL4) were reduced. DCs are an important source of chemokines influencing recruitment of distinct T-lymphocyte subsets. ATP, but not UTP, significantly reduced LPS-induced production of interferon-inducible protein 10 (CXCL10) and regulated upon activation, normal T-cell expressed and secreted chemokine (CCL5); increased secretion of macrophage-derived chemokine (CCL22); and did not change production of thymus and activation-regulated chemokine (CCL17). Consistent with these findings, supernatants from ATP-treated mature DCs attracted Th1 and T-cytotoxic 1 cells less efficiently, whereas migration of Th2 and T cytotoxic 2 cells was not affected. Our data suggest that ATP provides a signal for enhanced lymph node localization of DCs but that it may, at the same time, diminish the capacity of DCs to amplify type 1 immune responses.
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PMID:Dendritic cells exposed to extracellular adenosine triphosphate acquire the migratory properties of mature cells and show a reduced capacity to attract type 1 T lymphocytes. 1186 Dec 88

We systematically investigated the impact of the relative maturation levels of dendritic cells (DCs) on their cell surface phenotype, expression of cytokines and chemokines/chemokine receptors (by DNA array and RNase protection analyses), biological activities, and abilities to induce tumor immunity. Mature DCs expressed significantly heightened levels of their antigen-presenting machinery (e.g., CD54, CD80, CD86) and numerous cytokines and chemokines/chemokine receptors (i.e., Flt-3L, G-CSF, IL-1alpha and -1beta, IL-6, IL-12, CCL-2, -3, -4, -5, -17, and -22, MIP-2, and CCR7) and were significantly better at inducing effector T cell responses in vitro. Furthermore, mice vaccinated with tumor peptide-pulsed mature DCs better survived challenge with a weakly immunogenic tumor (8 of 8 survivors) than did mice vaccinated with less mature (3 of 8 survived) or immature (0 of 8 survivors) DCs. Nevertheless, intermediate-maturity DCs expressed substantial levels of Flt-3L, IGF-1, IL-1alpha and -1beta, IL-6, CCL-2, -3, -4, -9/10, -17, and -22, MIP-2, osteopontin, CCR-1, -2, -5, and -7, and CXCR-4. Taken together, our data clearly underscore the critical nature of employing DCs of full maturity for DC-based antitumor vaccination strategies.
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PMID:DNA array and biological characterization of the impact of the maturation status of mouse dendritic cells on their phenotype and antitumor vaccination efficacy. 1190 30

Murine CD4 and CD8 T cells express predominantly types 1 and 4 sphingosine 1-phosphate (S1P) G protein-coupled receptors (designated S1P1 and S1P4 or previously endothelial differentiation gene-encoded 1 and 6) for S1P, which has a normal plasma concentration of 0.1-1 microM. S1P now is shown to enhance chemotaxis of CD4 T cells to CCL-21 and CCL-5 by up to 2.5-fold at 10 nM to 0.1 microM, whereas 0.3-3 microM S1P inhibits this chemotaxis by up to 70%. Chemotaxis of S1P(1), but not S1P(4), transfectants to CXCL1 and CXCL4 was similarly affected by S1P. Activation of CD4 T cells, which decreases S1P receptor expression, suppressed effects of S1P on chemotaxis. Pretreatment of labeled CD4 T cells with S1P before reintroduction into mice inhibited by a maximum of 75% their migration into chemokine-challenged s.c. air pouches. The S1P-S1P(1) receptor axis thus controls recruitment of naive T cells by maintaining their response threshold to diverse lymphotactic factors.
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PMID:Cutting edge: suppression of T cell chemotaxis by sphingosine 1-phosphate. 1237 Mar 33

Type-1 and type-2 lung granulomas, respectively, elicited by bead immobilized Mycobacteria bovis and Schistosoma mansoni egg antigens (Ags) display different patterns of chemokine expression. This study tested the hypothesis that chemokine expression patterns were related to upstream cytokine signaling. Using quantitative transcript analysis, we defined expression profiles for 16 chemokines and then examined the in vivo effects of neutralizing antibodies against interferon-gamma (IFN-gamma), interleukin (IL)-4, IL-10, IL-12, and IL-13. Transcripts for CXCL2, -5, -9, -10, and -11 and the CCL chemokine, CCL3, and lymphotactin (XCL1), were largely enhanced by Th1-related cytokines, IFN-gamma or IL-12. Transcripts for CCL11, CCL22, CCL17, and CCL1 were enhanced largely by Th2-related cytokines, IL-4, IL-10, or IL-13. Transcripts for CCL4, CCL2, CCL8, CCL7, and CCL12 were potentially induced by either Th1- or Th2-related cytokines, although some of these showed biased expression. IFN-gamma and IL-4 enhanced the greatest complement of transcripts, and their neutralization had the greatest anti-inflammatory effect on type-1 and type-2 granulomas, respectively. Th1/Th2 cross-regulation was evident because endogenous Th2 cytokines inhibited type-1, whereas Th1 cytokines inhibited type-2 biased chemokines. These findings reveal a complex cytokine-chemokine regulatory network that dictates profiles of local chemokine expression during T cell-mediated granuloma formation.
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PMID:Cytokine-chemokine networks in experimental mycobacterial and schistosomal pulmonary granuloma formation. 1260 Aug 21

Prior studies and the efficacy of immunotherapies provide evidence that inflammation is mechanistic in pathogenesis of Duchenne muscular dystrophy. To identify putative pro-inflammatory mechanisms, we evaluated chemokine gene/protein expression patterns in skeletal muscle of mdx mice. By DNA microarray, reverse transcription-polymerase chain reaction, quantitative polymerase chain reaction, and immunoblotting, convergent evidence established the induction of six distinct CC class chemokine ligands in adult MDX: CCL2/MCP-1, CCL5/RANTES, CCL6/mu C10, CCL7/MCP-3, CCL8/MCP-2, and CCL9/MIP-1gamma. CCL receptors, CCR2, CCR1, and CCR5, also showed increased expression in mdx muscle. CCL2 and CCL6 were localized to both monocular cells and muscle fibers, suggesting that dystrophic muscle may contribute toward chemotaxis. Temporal patterns of CCL2 and CCL6 showed early induction and maintained expression in mdx limb muscle. These data raise the possibility that chemokine signaling pathways coordinate a spatially and temporally discrete immune response that may contribute toward muscular dystrophy. The chemokine pro-inflammatory pathways described here in mdx may represent new targets for treatment of Duchenne muscular dystrophy.
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PMID:Persistent over-expression of specific CC class chemokines correlates with macrophage and T-cell recruitment in mdx skeletal muscle. 1260 4

We have used human brain-derived endothelial cells (HBECs) maintained under basal culture conditions in a Boyden chamber assay system as an in vitro model of migration of cells of systemic immune origin across the blood brain barrier (BBB) during the initiation of a CNS-directed inflammatory response. In this study we evaluated the molecular mechanisms that regulate passage of ex vivo peripheral blood-derived monocytes across this barrier and the effects of such migration on the properties of both the HBECs and the monocytes. Our results indicate that monocytes can migrate across HBECs in the absence of inflammatory conditions, at rates exceeding those of lymphocytes. Monocyte migration could be significantly inhibited by the addition of blocking antibodies to intercellular adhesion molecule (ICAM)-1, very late antigen (VLA)-4 integrin, and monocyte chemoattractant protein (CCL-2/MCP-1), or treatment with tissue inhibitor of metalloproteinase (TIMP-1). Following monocyte migration there was a significant increase in permeability of soluble molecules and an enhanced rate of T cell migration across HBECs. The enhanced permeability could be partially prevented with anti-TNF-alpha antibody. The migration process did not induce the upregulation of either co-stimulatory molecules or chemokine receptors on the monocytes. These studies emphasize the functional role of monocyte-endothelial interactions in permitting target access of a CNS-directed cell-mediated immune response.
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PMID:Regulation and functional effects of monocyte migration across human brain-derived endothelial cells. 1272 33

Estrogen contributes to the development of breast cancer through mechanisms that are not completely understood. Estrogen influences the function of immune effector cells, primarily through alterations in cytokine expression. Chemokines are proinflammatory cytokines that attract various immune cells to the site of tissue injury or inflammation, and activate many cell types, including T lymphocytes and monocytes. As an initial step toward ultimately determining whether regulation of chemokine expression and/or biological activity by estrogen could potentially be a contributing factor to the development and progression of mammary tumors, we evaluated the effect of estrogen on the expression of specific chemokines in murine mammary tissue. We also evaluated whether exposure of female mice to various chemokines could alter the growth of mammary tumors in the presence of estrogen. We report here that estrogen significantly decreases levels of the chemokines MIP-1alpha and MCP-1/JE in murine mammary tissue. Co-treatment with 4-hydroxytamoxifen partially reverses the suppressive effect of estrogen on MIP-1alpha levels. Estrogen increases the growth of CCL- 51 cell-based tumors in the mammary glands of female mice. Co-treatment with the chemokine MIP-1alpha or MCP- 1/JE substantially decreases the ability of estrogen to stimulate the formation of CCL-51 cell-based tumors. Our results show that estrogen might influence the bioactivity of specific chemokines through alteration of chemokine expression in mammary tissue, and further suggest that decreases in murine chemokines evoked by estrogen exposure could contribute to the promotion of mammary tumor growth.
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PMID:Estrogen decreases chemokine levels in murine mammary tissue: implications for the regulatory role of MIP-1 alpha and MCP-1/JE in mammary tumor formation. 1466 21

The Duffy antigen/ receptor for chemokine, DARC, acts as a widely expressed promiscuous chemokine receptor and as the erythrocyte receptor for Plasmodium vivax. To gain insight into the evolution and structure/function relations of DARC, we analyzed the binding of anti-human Fy monoclonal antibodies (mAbs) and human chemokines to red blood cells (RBCs) from 11 nonhuman primates and two nonprimate mammals, and we elucidated the structures of the DARC genes from gorilla, gibbon, baboon, marmoset, tamarin, night monkey and cattle. CXCL-8 and CCL-5 chemokine binding analysis indicated that the promiscuous binding profile characteristic of DARC is conserved across species. Among three mAbs that detected the Fy6 epitope by flow cytometric analysis of human and chimpanzee RBCs, only one reacted with night monkey and squirrel monkey. Only chimpanzee RBCs bound a significant amount of the anti-Fy3 mAb. Fy3 was also poorly detected on RBCs from gorilla, baboon and rhesus monkey, but not from new world monkeys. Alignment of DARC homologous sequences allowed us to construct a phylogenetic tree in which all branchings were in accordance with current knowledge of primate phylogeny. Although DARC was expected to be under strong internal and external selection pressure, in order to maintain chemokine binding and avoid Plasmodium vivax binding, respectively, our present study did not provide arguments in favor of a selection pressure on the extracellular domains involved in ligand specificity. The amino acid variability of DARC-like polypeptides was found to be well correlated with the hydrophilicity indexes, with the highest divergence on the amino-terminal extracellular domain. Analysis of the deduced amino acid sequences highlighted the conservation of some amino acid residues, which should prove to be critical for the structural and functional properties of DARC.
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PMID:Sequence, evolution and ligand binding properties of mammalian Duffy antigen/receptor for chemokines. 1471 31

Chemokines are pro-inflammatory cytokines that function to attract immune cells to the sites of tissue inflammation, injury or infection. We have formulated the hypothesis that release of one chemokine can serve, in a local paracrine or endocrine fashion, to induce the release of other chemokines from neighboring mammary cells. We set out to investigate whether specific chemokines could promote the release of other chemokine members from mammary cells, and whether estrogen could serve to disrupt the release of these chemokines from mammary cells. We found that treatment with the chemokine IP-10 resulted in significant increases in the amount of MIP-1alpha and MCP-1/JE released from murine mammary cells. Estrogen co-treatment significantly blocked the ability of IP-10 to trigger the release of MIP-1alpha and MCP-1/JE. Suppressive effects of estrogen were reversed upon co-treatment with 4-hydroxytamoxifen. Estrogen treatment significantly decreased expression of proteins corresponding to the chemokine receptors CXCR3 and CCR5 on mammary cells. Exposure of female mice to IP-10 in vivo significantly decreased the ability of estrogen to support the growth of CCL-51-based tumors in mammary tissue. Our results suggest that exposure of mammary tissue to estrogen may decrease the release of local chemokines from mammary cells, potentially increasing the risk of tumor growth through decreased immune surveillance. Ongoing studies are investigating the possible mechanisms through which IP-10 stimulates the release of chemokines from mammary cells, and how the action of IP-10 may serve to decrease mammary tumor formation.
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PMID:Estrogen disrupts chemokine-mediated chemokine release from mammary cells: implications for the interplay between estrogen and IP-10 in the regulation of mammary tumor formation. 1502 21


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