Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CC chemokines produced by CD8(+) T cells are known to act as HIV-suppressive factors. We studied the possible role of these chemokines in HIV-1-specific killing of target cells. We found that the activity of cytotoxic T lymphocytes (CTLs) in CTL lines or freshly isolated peripheral blood mononuclear cells from HIV-1-infected individuals is markedly enhanced by RANTES (regulated on activation, normal T cell expressed and secreted) and virtually abolished by an antibody neutralizing RANTES or the RANTES receptor antagonist RANTES(9-68). Lysis was mediated by CD8(+) major histocompatibility complex class I-restricted T cells and was obtained with target cells expressing epitopes of the HIV-1LAI proteins Gag, Pol, Env, and Nef. The cytolytic activity observed in the presence or absence of added RANTES could be abolished by pretreatment of the CTLs with pertussis toxin, indicating that the effect is mediated by a G protein-coupled receptor. The chemokines monocyte chemotactic protein (MCP)-3, MCP-4, and eotaxin acted like RANTES, whereas macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, MCP-1, and stromal cell-derived factor 1 were inactive, suggesting a role for the eotaxin receptor, CCR3, and ruling out the involvement of CCR1, CCR2, CCR5, and CXCR4. CTL activity was abrogated by an antibody that blocks CCR3, further indicating that specific lysis is triggered via this chemokine receptor. These observations reveal a novel mechanism for the induction of HIV-1-specific cytotoxicity that depends on RANTES acting via CCR3.
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PMID:HIV-specific T cell cytotoxicity mediated by RANTES via the chemokine receptor CCR3. 968 38

Following liver injury, hepatic stellate cells (HSC) undergo proliferation and migrate into damaged areas in response to chemotactic factors. HSC have been shown to regulate leukocyte trafficking by secreting monocyte chemotactic protein-1 (MCP-1), a chemokine that recruits monocytes and lymphocytes. In this study, we explored whether MCP-1 exerts biological actions on HSC. HSC were isolated from normal human livers, cultured on plastic, and studied in their myofibroblast-like phenotype, and three different cells lines were used. Chemotaxis was measured in modified Boyden chambers. Phosphatidylinositol 3-kinase (PI 3-K) was assayed on phosphotyrosine immunoprecipitates. Exposure of HSC to MCP-1 stimulated migration of HSC in a dose-dependent fashion. Maximal stimulation was obtained with 250 ng/mL MCP-1, which resulted in a 3- to 4-fold stimulation of cell migration. Checkerboard analysis showed that the increase in cell migration was almost completely a result of chemotaxis rather than chemokinesis. In contrast, in quiescent HSC, MCP-1 did not exert any effect on cell migration. In leukocytes, MCP-1 activates the pertussis toxin-sensitive CCR2 receptor. However, transcripts for CCR2 could not be shown in HSC, and pertussis toxin only modestly inhibited MCP-1-induced migration. Exposure of HSC to MCP-1 was associated with an increase in cytosolic calcium concentration, PI 3-K activity, protein tyrosine phosphorylation. Blocking calcium influx or pretreatment of HSC with the PI 3-K inhibitor wortmannin markedly reduced cell migration. This study shows, for the first time, a potential direct profibrogenic action of MCP-1 via HSC chemotaxis. MCP-1-dependent signals in these cells are not transduced by CCR2 and may be mediated by alternative chemokine receptors. (HEPATOLOGY 1999;29:140-148.)
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PMID:Monocyte chemotactic protein-1 as a chemoattractant for human hepatic stellate cells. 986 60

The receptor specificity and signal transduction pathway has been identified and characterized for a truncated form of myeloid progenitor inhibitory factor-1 (MPIF-1(24-99)). MPIF-1 binds specifically to sites, in particular CCR1, shared with macrophage inflammatory protein-1alpha (MIP-1alpha) on the surface of human monocytes and dendritic cells, as inferred by its ability to compete for [125I]MIP-1alpha, but not for [125I]MIP-1beta or [125I]monocyte chemotactic protein-1(MCP-1) binding to intact cells. Based on calcium flux, MPIF-1 is an agonist on CCR1-transfected HEK-293 cells, monocytes, and dendritic cells, but not on CCR5-, CCR8-, or CX3CR1-transfected cells. The inhibitory effect of guanosine 5'-O-(3-thio-triphosphate) (GTP-gammaS) or pertussis toxin pretreatment on MPIF-1 binding and calcium mobilization, respectively, indicates the involvement of G proteins in the interaction of MPIF-1 and its receptor(s). The increase in intracellular free calcium concentration following MPIF-1 treatment is mainly due to the influx of calcium from an extracellular pool. However, a portion of the intracellular free calcium concentration is derived from a phospholipase C inhibitor-sensitive intracellular pool. MPIF-1 induces a rapid dose-dependent release of [3H]arachidonic acid from monocytes that is dependent on extracellular calcium and is blocked by phospholipase A2 (PLA2) inhibitors. Furthermore, PLA2 activation is shown to be necessary for filamentous actin formation in monocytes. Thus, the MPIF-1 signal transduction pathway appears to include binding to CCR1; transduction by G proteins; effector function by phospholipase C, protein kinase C, calcium flux, and PLA2; and cytoskeletal remodeling.
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PMID:Characterization of the signal transduction pathway activated in human monocytes and dendritic cells by MPIF-1, a specific ligand for CC chemokine receptor 1. 988 17

Using the recently developed methodology of nucleic acid microarrays spotted with specific cDNAs probes belonging to different gene families, we showed for the first time that nanomolar concentrations of the cannabinoid ligand CP-55940 upregulated the expression of two different members of the chemokine gene family: the alpha-chemokine interleukin-8 (IL-8) and the beta-chemokine monocyte chemotactic protein-1 (MCP-1), in the promyelocytic cell line HL60 transfected with peripheral cannabinoid receptors (CB2). These genomic modulations observed on large-scale cDNA arrays were first confirmed by Northern blot studies. Furthermore, ELISA evaluations in culture supernatants indicated that the cannabinoid-induced activation of these two chemokine genes was followed by enhanced expression and secretion of the corresponding proteins. These upregulations initially observed in transfected HL60 cells overexpressing CB2 receptors, also occurred in normal non-transfected HL60 cells. The enhancement of IL-8 and MCP-1 gene transcription and protein production was shown to be pertussis toxin sensitive attesting that this phenomenon was a Gi protein-coupled receptor-mediated process as expected for cannabinoid receptors. More specifically, the abolition of the cannabinoid-induced effect by the specific CB2 antagonist SR 144528 indicated a strict peripheral cannabinoid-mediated process. Altogether, our data highlight a possible new function of peripheral cannabinoid receptors in the modulation of immune and inflammatory responses.
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PMID:Stimulation of peripheral cannabinoid receptor CB2 induces MCP-1 and IL-8 gene expression in human promyelocytic cell line HL60. 1021 91

Galectin-3 is a beta-galactoside-binding protein implicated in diverse biological processes. We found that galectin-3 induced human monocyte migration in vitro in a dose-dependent manner, and it was chemotactic at high concentrations (1.0 microM) but chemokinetic at low concentrations (10-100 nM). Galectin-3-induced monocyte migration was inhibited by its specific mAb and was blocked by lactose and a C-terminal domain fragment of the protein, indicating that both the N-terminal and C-terminal domains of galectin-3 are involved in this activity. Pertussis toxin (PTX) almost completely blocked monocyte migration induced by high concentrations of galectin-3. Galectin-3 caused a Ca2+ influx in monocytes at high, but not low, concentrations, and both lactose and PTX inhibited this response. There was no cross-desensitization between galectin-3 and any of the monocyte-reactive chemokines examined, including monocyte chemotactic protein-1, macrophage inflammatory protein-1alpha, and stromal cell-derived factor-1alpha. Cultured human macrophages and alveolar macrophages also migrated toward galectin-3, but not monocyte chemotactic protein-1. Finally, galectin-3 was found to cause monocyte accumulation in vivo in mouse air pouches. These results indicate that galectin-3 is a novel chemoattractant for monocytes and macrophages and suggest that the effect is mediated at least in part through a PTX-sensitive (G protein-coupled) pathway.
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PMID:Human galectin-3 is a novel chemoattractant for monocytes and macrophages. 1092 2

The monocyte chemotactic protein-1 (MCP-1) receptor (MCP-1R) is expressed on monocytes, a subpopulation of memory T lymphocytes, and basophils. Two alternatively spliced forms of MCP-1R, CCR2A and CCR2B, exist and differ only in their carboxyl-terminal tails. To determine whether CCR2A and CCR2B receptors function similarly, Jurkat T cells were stably transfected with plasmids encoding the human CCR2A or CCR2B gene. Nanomolar concentrations of MCP-1 induced chemotaxis in the CCR2B transfectants that express high, intermediate, and low levels of MCP-1R. Peak chemotactic activity was shifted to the right as receptor number decreased. Five-fold more MCP-1 was required to initiate chemotaxis of the CCR2A low transfectant, but the peak of chemotaxis was similar for the CCR2A and CCR2B transfectants expressing similar numbers of receptors. MCP-1-induced chemotaxis was sensitive to pertussis toxin, implying that both CCR2A and CCR2B are G(i)alpha protein coupled. MCP-1 induced a transient Ca(2+) flux in the CCR2B transfectant that was partially sensitive to pertussis toxin. In contrast, MCP-1 did not induce Ca(2+) flux in the CCR2A transfectant. Since MCP-1 can stimulate chemotaxis of the CCR2A transfectant without inducing Ca(2+) mobilization, Ca(2+) flux may not be required for MCP-1-induced chemotaxis in the Jurkat transfectants. These results indicate that functional differences exist between the CCR2A and CCR2B transfectants that can be attributed solely to differences in the carboxyl-terminal tail.
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PMID:Functional differences between monocyte chemotactic protein-1 receptor A and monocyte chemotactic protein-1 receptor B expressed in a Jurkat T cell. 1104 12

Chemokine receptors of both the CC and CXC families have been demonstrated to undergo a ligand-mediated homodimerization process required for Ca2+ flux and chemotaxis. We show that, in the chemokine response, heterodimerization is also permitted between given receptor pairs, specifically between CCR2 and CCR5. This has functional consequences, as the CCR2 and CCR5 ligands monocyte chemotactic protein-1 (MCP-1) and RANTES (regulated upon activation, normal T cell-expressed and secreted) cooperate to trigger calcium responses at concentrations 10- to 100-fold lower than the threshold for either chemokine alone. Heterodimerization results in recruitment of each receptor-associated signaling complex, but also recruits dissimilar signaling path ways such as G(q/11) association, and delays activation of phosphatidyl inositol 3-kinase. The consequences are a pertussis toxin-resistant Ca2+ flux and trig gering of cell adhesion rather than chemotaxis. These results show the effect of heterodimer formation on increasing the sensitivity and dynamic range of the chemokine response, and may aid in understanding the dynamics of leukocytes at limiting chemokine concentrations in vivo.
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PMID:Chemokine receptor homo- or heterodimerization activates distinct signaling pathways. 1135 Sep 39

Rheumatoid arthritis (RA) is characterized by proliferation of synoviocytes that produce inflammatory cytokines and chemokines. The expressed chemokines are thought to be involved in the migration of inflammatory cells into the synovium. In this study we show that CCL2/monocyte chemotactic protein-1, CCL5/RANTES, and CXCL12/stromal cell-derived factor-1 enhanced IL-6 and IL-8 production by fibroblast-like synoviocytes (FLS) from patients with RA, and their corresponding receptors, CCR2, CCR5, and CXCR4, respectively, were expressed by RA FLS. The chemokines stimulated RA FLS more effectively than skin fibroblasts. Culture with CCL2 enhanced phosphorylation of extracellular signal-related kinase 1 (ERK1) and ERK2, but not phosphorylation of p38 or Src. Moreover, activation of ERK1/2 was inhibited by pertussis toxin, a G(i)-coupled protein inhibitor, and RS-504393, CCR2 antagonist, suggesting that ERK1/2 was activated by CCL2 via CCR2 and G(i)-coupled protein. On the other hand, CCL2, CCL5, and CXCL12 were expressed on RA FLS, and their production was regulated by TNF-alpha, IL-1beta, and TGF-beta1. Our results indicate that the chemokines not only play a role in inflammatory cell migration, but are also involved in the activation of FLS in RA synovium, possibly in an autocrine or paracrine manner.
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PMID:Chemokines regulate IL-6 and IL-8 production by fibroblast-like synoviocytes from patients with rheumatoid arthritis. 1167 56

Human immunodeficiency virus type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry. It was recently demonstrated that HIV-1 glycoprotein 120 (gp120) elevated calcium and activated several ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. This study shows that chemokine receptor engagement by both CCR5-dependent (R5) and CXCR4-dependent (X4) gp120 led to rapid phosphorylation of the focal adhesion-related tyrosine kinase Pyk2 in macrophages. Pyk2 phosphorylation was also induced by macrophage inflammatory protein-1beta (MIP-1beta) and stromal cell-derived factor-1alpha, chemokine ligands for CCR5 and CXCR4. Activation was blocked by EGTA and by a potent blocker of calcium release-activated Ca++ (CRAC) channels, but was insensitive to pertussis toxin (PTX), implicating CRAC-mediated extracellular Ca++ influx but not Galpha(i) protein-dependent mechanisms. Coreceptor engagement by gp120 and chemokines also activated 2 members of the mitogen-activated protein kinase (MAPK) superfamily, c-Jun amino-terminal kinase/stress-activated protein kinase and p38 MAPK. Furthermore, gp120-stimulated macrophages secreted the chemokines monocyte chemotactic protein-1 and MIP-1beta in a manner that was dependent on MAPK activation. Thus, the gp120 signaling cascade in macrophages includes coreceptor binding, PTX-insensitive signal transduction, ionic signaling including Ca++ influx, and activation of Pyk2 and MAPK pathways, and leads to secretion of inflammatory mediators. HIV-1 Env signaling through these pathways may contribute to dysregulation of uninfected macrophage functions, new target cell recruitment, or modulation of macrophage infection.
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PMID:HIV-1 gp120 and chemokine activation of Pyk2 and mitogen-activated protein kinases in primary macrophages mediated by calcium-dependent, pertussis toxin-insensitive chemokine receptor signaling. 1169 70

Mounting evidence suggests that lipopolysaccharide (LPS) modulates bronchoconstriction and eosinophil function in asthma. We have investigated the role of different chemokines in the eosinophil influx to the pleural cavity after LPS stimulation. Expression of mRNA for eotaxin, regulated on activation, normal T cells expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, MIP-2, and monocyte chemotactic protein (MCP)-1 was increased in cells recovered from the mouse pleural cavity 6 h after LPS administration. Eotaxin and RANTES, but not MIP-1alpha, protein levels were also increased in cell-free pleural washes recovered 6 h after LPS stimulation (LPW). Antimurine eotaxin and antimurine RANTES antibodies (Abs) failed to inhibit LPS-induced eosinophil influx into mouse pleural cavity in vivo. Pertussis toxin inhibited LPW-induced eosinophil shape change in vitro, suggesting the involvement of G protein-coupled receptors in LPW signaling. Blockade of CCR3 receptors diminished eosinophil shape change induced by LPW fractions in vitro and LPS-induced eosinophil accumulation in vivo. To investigate further contribution of CC chemokines, we administered a 35-kD CC chemokine neutralizing protein (vCKBP) in vivo. vCKBP inhibited the eosinophil accumulation induced by eotaxin and ovalbumin, but did not block that induced by LPS or LPW. Our data suggest that LPS-induced eosinophil accumulation depends on G protein-coupled CCR3 receptor activation, through a mechanism independent of eotaxin, RANTES, or other vCKBP-inhibitable CC chemokines.
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PMID:LPS induces eosinophil migration via CCR3 signaling through a mechanism independent of RANTES and Eotaxin. 1172 91


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