UMLS:C0043167 - FACTA Search

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Query: UMLS:C0043167 (pertussis)
19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NK cells are present mostly in blood and spleen but under certain pathological and physiological conditions rapidly accumulate at extrahematic sites. The present study investigates the responsiveness of NK cells to C-C chemokines and the mechanisms of emigration from the bloodstream. MCP-1 induced migration across polycarbonate filters of IL-2-activated NK cells, whereas it was a weak attractant for unstimulated cells. The related chemokines MCP-2 and MCP-3 were also active. IL-2-activated NK cells showed specific binding sites for labeled MCP-1, and cell migration was inhibited by both cholera and Bordetella pertussis toxins. In agreement with functional assays the expression of mRNA specific for MCP-1 receptors was detectable only in IL-2-activated NK cells. The ability of NK cells to respond to MCP-1 and related chemokines may be one important determinant of NK cell emigration and recruitment in tissues.
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PMID:Migratory Response of Human NK Cells to Monocyte-Chemotactic Proteins 881 55

IL-2-activated NK cells from PVG rats potently lyse target cells expressing allo-MHC class I determinants. Here, we investigated the role that G proteins play in mediating this activity. Pretreatment of NK cells with pertussis toxin (PT) or cholera toxin (CT) inhibited NK cell killing of tumor (YAC-1 or P815), and allogeneic target cells. ADP ribosylation assay revealed that PT ADP ribosylates a 39-kDa G protein, whereas CT ADP ribosylates a 45 to 47-kDa G protein in PVG NK cell membranes. Membranes prepared from intoxicated NK cells with either PT or CT lost their ability to incorporate [32P]NAD. These membranes possess Gi, Go, Gs, and Gz as demonstrated by immunoblot analysis. However, Gq was not clearly detected by this method. IL-2-activated NK cells were permeabilized with streptolysin O. Permeabilized cells incorporated Abs to Gi, Go, Gz, Gs, and Gq as determined by flow cytometric analysis. When Abs to Go or Gz, but not to Gi, Gs, or Gq, were incorporated inside permeabilized NK cells, a significant reduction in the lysis of tumor or allo-MHC target cells was observed, suggesting that Go and Gz play important roles in transducing the signals necessary to lyse target cells. Our results show for the first time a role for G proteins in mediating NK cell killing of allo-MHC-encoded target cells, and provide evidence for Gz protein involvement in NK cell recognition of target cells. The effect of Gz is novel and has not been previously described in any other system or cell type.
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PMID:Preferential involvement of Go and Gz proteins in mediating rat natural killer cell lysis of allogeneic and tumor target cells. 895 77

In an investigation of cell-mediated immunity against Bordetella pertussis, we found that B. pertussis infection in infants and in mice was associated with the induction of antigen-specific T cells that secrete IFN-g and IL-2, but not IL-4 or IL-5. This cytokine profile is characteristic of Th1 cells that mediate cellular immune responses against a range of intracellular pathogens. An examination of cytokine production following immunization with a three-component acellular vaccine, comprising inactive PT, FHA and pertactin adsorbed to alum, demonstrated that spleen cells from vaccinated mice produced high levels of IL-5, but no detectable IFN-g and low levels of IL-2. In contrast, peripheral blood mononuclear cells from vaccinated infants produced IL-2, IL-5 and IFN-g. These findings highlight significant differences in the immune responses generated by vaccination and natural infection with B. pertussis and demonstrate that the T-cell response induced with an acellular vaccine, although dominated by type 2 cytokines in mice, is more heterogeneous in infants with a Th0 or mixed Th1/Th2 cytokine profile.
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PMID:Bordetella pertussis-specific Th1/Th2 cells generated following respiratory infection or immunization with an acellular vaccine: comparison of the T cell cytokine profiles in infants and mice. 927 63

The effect on antigen (Ag)-specific Th2 response as well as IgE production of continuous oral administration of micro-doses of Ag was investigated. Transgenic (Tg) mice carrying the alphabeta-T cell receptor (TCR) genes specific for ovalbumin (OVA) peptide fragment 323-339 were continuously fed with micro-doses of OVA (100 microg/day) for 14 days. Mice were first immunized by OVA in alum and pertussis toxin 7 days before the oral feeding and given a second immunization 1 day after the oral treatment. This feeding regimen tolerized Th2 but not Th1 responses as shown by decrease of Ag-driven cell proliferation and cytokine secretion of IL-4 but not of IL-2 or IFN-gamma as well as by the absence of Ag-specific antibody production of IgE and IgG1, but not of IgG2a or total IgG. Numbers of clonotype-specific TCR-high CD4-positive T cells in peripheral lymphoid tissues markedly decreased in the orally treated group but not in the control group. However, total numbers of CD4-positive T cells in thymus, spleen and lymph nodes were not affected by the oral treatment, indicating that tolerance induction in Th2 cells was mainly due to the down-regulation of TCR and not clonal deletion. The population of antigen-presenting cells expressing B7-2 (CD86) Ag on the surface was decreased in the spleen of the mice which underwent the feeding regimen. The present results suggest that Ag-specific low responsiveness in Th2 cells, which resulted in suppression of the Ag-specific IgE production, can be achieved by continuous feeding with microdoses of Ag.
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PMID:Selective suppression of antigen-specific Th2 cells by continuous micro-dose oral tolerance. 948 93

We have used a murine respiratory challenge model to examine the local T cell responses in the lung during infection with Bordetella pertussis. T cells from lung parenchyma and airways of naive and infected mice were refractory to both antigen and mitogen stimulation in the presence of lung macrophages. Furthermore irradiated mononuclear cells from the lungs suppressed antigen and mitogen-induced proliferation, but not IFN-gamma production, by splenic T cells. Removal of macrophages and stimulation of purified lung T cells in the presence of irradiated splenic antigen-presenting cells fully restored the response to mitogen. However, T cells purified from the lung during the acute phase of infection with B. pertussis failed to proliferate or produce detectable levels of IL-2, IL-4, IL-5 or IFN-gamma in response to purified bacterial antigens. In contrast, splenic T cells from these animals produced high levels of IL-2 and IFN-gamma and proliferated strongly to a range of bacterial components. Phenotypic analysis of bronchoalveolar lavage cells during the course of infection revealed transient infiltration of neutrophils, followed by macrophages, CD4+ T cells and smaller numbers of CD8+ T cells and gammadelta+ T cells. Cell surface expression of B7 on infiltrating macrophages and CTLA-4 on T cells did not change significantly during infection. However, expression of the CD28 co-stimulatory molecule was profoundly reduced on lung T cells during the acute phase of infection. In contrast, lung T cells from mice primed by B. pertussis infection or vaccination were resistant to CD28 down-regulation. These results suggest compartmentalization of T cell responses between the lung and the periphery during B. pertussis infection and that B. pertussis may have immunomodulatory properties on local T cell populations in the lungs of naive mice.
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PMID:Compartmentalization of T cell responses following respiratory infection with Bordetella pertussis: hyporesponsiveness of lung T cells is associated with modulated expression of the co-stimulatory molecule CD28. 948 95

Pertussis toxin (PT) is a major virulence factor of Bordetella pertussis which exerts a range of effects on the immune system, including the enhancement of IgE, IgA and IgG production, delayed-type hypersensitivity reactions, and the induction of experimental autoimmune diseases. However, the mechanism by which PT mediates adjuvanticity remains to be defined. In this investigation we have shown that PT can potentiate antigen-specific T cell proliferation and the secretion of IFN-gamma, IL-2, IL-4 and IL-5 when injected with foreign antigens. A chemically detoxified PT and a genetic mutant with substitutions/deletions in the S-1 and B oligomer components that abrogate enzymatic and binding activity displayed no adjuvant properties. In contrast, a non-toxic S-1 mutant devoid of enzymatic activity but still capable of receptor binding retained its adjuvanticity, augmenting the activation of both Th1 and Th2 subpopulations of T cells. In an attempt to address the mechanism of T cell activation, we found that PT stimulated the production of IFN-gamma and IL-2 by naive T cells and IL-1 by macrophages. Therefore potentiation of distinct T cell subpopulations may have resulted in part from the positive influence of IFN-gamma on the development of Th1 cells and the co-stimulatory role of IL-1 for Th2 cells. Furthermore, PT augmented expression of the co-stimulatory molecules B7-1 and B7-2 on macrophages and B cells, and CD28 on T cells, suggesting that the adjuvant effect may also be associated with facilitation of the second signal required for maximal T cell activation. This study demonstrates that the immunopotentiating properties of PT are largely independent of ADP-ribosyltransferase activity, but are dependent on receptor binding activity and appear to involve enhanced activation of T cells.
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PMID:Pertussis toxin potentiates Th1 and Th2 responses to co-injected antigen: adjuvant action is associated with enhanced regulatory cytokine production and expression of the co-stimulatory molecules B7-1, B7-2 and CD28. 964 13

Leukocyte migration into sites of inflammation involves multiple molecular interactions between leukocytes and vascular endothelial cells, mediating sequential leukocyte capture, rolling, and firm adhesion. In this study, we tested the role of molecular interactions between fractalkine (FKN), a transmembrane mucin-chemokine hybrid molecule expressed on activated endothelium, and its receptor (CX3CR1) in leukocyte capture, firm adhesion, and activation under physiologic flow conditions. Immobilized FKN fusion proteins captured resting peripheral blood mononuclear cells at physiologic wall shear stresses and induced firm adhesion of resting monocytes, resting and interleukin (IL)-2-activated CD8(+) T lymphocytes and IL-2-activated NK cells. FKN also induced cell shape change in firmly adherent monocytes and IL-2-activated lymphocytes. CX3CR1-transfected K562 cells, but not control K562 cells, firmly adhered to FKN-expressing ECV-304 cells (ECV-FKN) and tumor necrosis factor alpha-activated human umbilical vein endothelial cells. This firm adhesion was not inhibited by pertussis toxin, EDTA/EGTA, or antiintegrin antibodies, indicating that the firm adhesion was integrin independent. In summary, FKN mediated the rapid capture, integrin-independent firm adhesion, and activation of circulating leukocytes under flow. Thus, FKN and CX3CR1 mediate a novel pathway for leukocyte trafficking.
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PMID:Fractalkine and CX3CR1 mediate a novel mechanism of leukocyte capture, firm adhesion, and activation under physiologic flow. 978 18

NK cell proliferation is suppressed in some patients with cancer by unknown mechanisms. Because purine metabolites released into the extracellular space during cell lysis may affect cell function, we hypothesized that these metabolites could serve as feedback regulators of NK cell proliferation. Sorted NK (CD56+/CD3-) cells were incubated with IL-2 (1000 U/ml) in a 4-day thymidine uptake assay with or without 10-10,000 microM of nucleotides. Adenine nucleotides inhibited NK cell proliferation, with ATP = ADP > 5'-adenylylimidodiphosphate > AMP = adenosine; ADP-ribose and nicotinamide adenine dinucleotide, but not nicotinamide or UTP, caused a dose-dependent suppression of thymidine uptake. A total of 100 microM ATP, a concentration that induced a maximal (80%) inhibition of thymidine uptake, did not inhibit cytotoxic activity against K562 targets. Because NK cells retained the ability to lyse K562 targets 4 days after exposure to 500 microM ATP or 1000 microM adenosine, inhibition of thymidine uptake was not due to cell death. Incubation of NK cells with dibutyryl cAMP and forskolin also suppressed thymidine uptake. Cholera toxin and pertussis toxin suppressed NK cell proliferation. Pertussis toxin did not block the adenine nucleotide effects. Further, ATP, but not adenosine or other nucleotides, markedly increased intracellular cAMP in a dose-dependent manner. The ATP-induced increase in cAMP was specific to cytolytic cells, because CD19+ B cells and CD4+ T cells did not increase their intracellular cAMP. These studies demonstrate that NK proliferation is regulated through purine receptors by adenine nucleotides, which may play a role in decreased NK cell activity. The response to adenine nucleotides is lineage-specific.
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PMID:Purine metabolites suppress proliferation of human NK cells through a lineage-specific purine receptor. 1035 89

We have developed a novel 3-D gel reconstituted with major extracellular matrix (ECM) glycoproteins to follow the dynamics of migration of human T cells locomoting, in real-time, on gradients formed by representative chemoattractants: the C-C chemokine RANTES, and the pro-inflammatory cytokine IL-2. In the absence of chemoattractants, none of the T cells migrated directionally and the levels of random migration or cell polarization were low. However, major fractions of T cells placed in IL-2 and RANTES gradients in the gels polarized immediately after exposure to the chemoattractants. Shortly after polarization, 25% of the T cells migrated, in either a random or directional fashion, towards the sources of the chemoattractants; additional 5-10% of the cells remained polarized but stationary. The number of T cells migrating directionally towards RANTES or IL-2 peaked along with the formation of the chemotactic gradients. The directional migration of T cells was increased by a short pre-exposure to low doses of IL-2, which did not alter the level of expression of the beta1 integrins. The directional migration of T cells towards IL-2 and RANTES was mediated by IL-2R and pertussis toxin-sensitive receptors, respectively, and the directional, and to a lesser degree, the random locomotion of T cells induced by both chemoattractants required intact tyrosine kinase signaling and activities of the alpha4, alpha5, and, to a lesser degree, the alpha2 and alpha6 members the beta1 integrins. Our system enables the real-time tracking of individual locomoting lymphocytes and the analysis of their dynamic interactions with ECM components and cytokines.
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PMID:Real-time analysis of integrin-mediated chemotactic migration of T lymphocytes within 3-D extracellular matrix-like gels. 1036 78

NK cells respond to various chemokines, suggesting that they express receptors for these chemokines. In this paper, we show that IL-2-activated NK (IANK) cells express CC chemokine receptor 4 (CCR4) and CCR8, as determined by flow cytometric, immunoblot, and RNase protection assays. Macrophage-derived chemokine (MDC), the ligand for CCR4, induces the phosphorylation of CCR4 within 0.5 min of activating IANK cells with this ligand. This is corroborated with the recruitment of G protein-coupled receptor kinases 2 and 3 and their association with CCR4 in IANK cell membranes. Also, CCR4 is internalized between 5 and 45 min but reappears in the membranes after 60 min of stimulation with MDC. MDC, thymus and activation-regulated chemokine (TARC), and I-309 induce the chemotaxis of IANK cells, an activity that is inhibited upon pretreatment of these cells with pertussis toxin, suggesting that receptors for these chemokines are coupled to pertussis toxin-sensitive G proteins. In the calcium release assay, cross-desensitization experiments showed that TARC completely desensitizes the calcium flux response induced by MDC or I-309, whereas both MDC and I-309 partially desensitize the calcium flux response induced by TARC. These results suggest that TARC utilizes CCR4 and CCR8. Our results are the first to show that IL-2-activated NK cells express CCR4 and CCR8, suggesting that these receptors are not exclusive for Th2 cells.
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PMID:Human NK cells express CC chemokine receptors 4 and 8 and respond to thymus and activation-regulated chemokine, macrophage-derived chemokine, and I-309. 1075 97

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