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)

Keratinocyte expression of class II antigens (HLA-DR, human; Ia, murine) is associated with certain cutaneous diseases, especially those marked by the infiltration of immune and inflammatory cells into the skin. It has been shown that interferon-gamma (IFN-gamma) is capable of inducing human keratinocytes to express HLA-DR. Similar results, however, have not been duplicated in murine systems. The purpose of this study was to determine whether IFN-gamma was capable of inducing murine keratinocyte expression of Ia in vivo in an experimental model in which epithelial cells in a variety of organs were shown to express Ia after the i.v. injection of IFN-gamma. Recombinant murine IFN-gamma was injected into BALB/c mice. Biopsies of skin and intestine were analyzed by indirect immunoperoxidase to identify Ia-expressing keratinocytes and mucosal cells, respectively. Interferon-gamma was administered as either: 1) a single s.c. injection, 2) multiple i.v. injections of increasing doses (10(3)-10(5) U/d) on 3 consecutive d, or 3) i.p. injections of 5 X 10(4) U/d or 5 X 10(5) U/d on 6 consecutive d. At all i.v. and i.p. injection doses, the intestinal villi mucosal cells were induced to express Ia. Keratinocyte expression of Ia, however, was observed only in animals that received the two higher i.p. doses. Procedures to augment Ia expression, e.g., combined treatment with pertussis toxin, dinitrofluorobenzene, tumor necrosis factor, and indomethacin, did not enhance the ability of IFN-gamma to induce keratinocyte expression of Ia. We conclude that: 1) high doses of IFN-gamma are required to induce murine keratinocyte Ia expression in vivo and 2) low doses of IFN-gamma, although capable of inducing intestinal mucosal cells to express Ia, do not induce keratinocyte Ia expression.
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PMID:Differential expression of Ia by murine keratinocytes and gut epithelium in response to recombinant gamma-interferon. 230 58

We studied the chemotactic peptide receptor/cytoskeletal interactions in HL-60 cells induced to differentiate with different agents and attempted to correlate these observations with the acquisition of different functional responses. Dibutyryl cyclic AMP-treated cells showed rapid superoxide anion production in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP) and slow, sustained response to phorbol myristate acetate (PMA). Retinoic acid-induced cells showed a slow, sustained response to both FMLP and PMA. Interferon-gamma-treated cells produced no superoxide anion on stimulation with FMLP, whereas tumor necrosis factor (TNF)-treated cells showed a slight response. Chemotactic peptide receptor association was the same in the HL-60 cells treated with different agents, despite marked differences in the superoxide anion generation and actin polymerization responses to FMLP and PMA in these cells. In mature neutrophils chemotactic peptide receptor association with the cytoskeleton was not affected by either pertussis or cholera toxin. However, both toxins inhibited FMLP-induced actin polymerization and superoxide anion generation. This suggested involvement of a G-protein similar to Gt, rather than Gi or Gs. Neither toxin had any effect on PMA-induced superoxide anion generation. These observations indicate that receptor association with the cytoskeleton may not have a significant role in affecting signal recognition and response. Among the several possible roles suggested, clearance of the occupied receptors may be the most important role of the cytoskeletal association. HL-60 cells induced to differentiate with different agents (because of their varied functional responses) might prove very useful in dissecting the molecular mechanisms regulating stimulus-induced activation of neutrophils.
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PMID:Chemotactic peptide receptor-cytoskeletal interactions and functional correlations in differentiated HL-60 cells and human polymorphonuclear leukocytes. 255 Apr 79

Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) are cytokines with important functions in regulating immune responses. IFN-gamma may be produced by cells responsible for delayed-type hypersensitivity (DTH), whereas IL-4 is essential for IgE production. Pertussis toxin (PT) from Bordetella pertussis enhances both DTH and IgE responses, and causes enhancement of both IFN-gamma and IL-4 secretion in immunized mice. In the present study, the effects of neutralizing monoclonal antibodies against IFN-gamma or IL-4 on DTH, serum IgE and cytokine production were assessed. Treatment with a monoclonal anti-IL-4 antibody at the time of immunization caused a striking increase in DTH responses, and elicited enhanced IFN-gamma expression, while inhibition of the production of IL-4 and IgE was observed. By contrast, injection of a monoclonal anti-IFN-gamma antibody was followed by significant but not complete suppression of DTH reactions. IFN-gamma secretion was also inhibited, whereas IL-4 production and serum IgE were increased. Thus antibodies to IL-4 and IFN-gamma, given at the time of immunization, can profoundly influence the nature of short-term immune responses elicited by PT in immunized mice.
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PMID:Regulation of DTH and IgE responses by IL-4 and IFN-gamma in immunized mice given pertussis toxin. 787 44

Interferon-gamma (IFN-gamma) is a potent growth-inhibitory cytokine also endowed with differentiating activity on neural cells. Binding of IFN-gamma to its high-affinity receptor induces a rapid and transient activation of phospholipase A2 (PLA2). The mechanism coupling the IFN-gamma receptor (IFN-gamma-R) to PLA2 activation is not clearly defined, and no information is available on this mechanism in neuroblast cells. We have tested the hypothesis that GTP-binding proteins (G-proteins) may couple the IFN-gamma-R to PLA2 in the human neuroblastoma (NB) cell line LAN-5. Incubation of NB cells with IFN-gamma resulted in a rapid increase in [3H]arachidonic acid (AA) release, and this effect was blocked by pretreatment with anti-IFN-gamma antibodies. IFN-gamma-stimulated AA release was still observed in permeabilized cells that were blocked by pretreatment with anti-IFN-gamma-R antibodies. Exposure of permeabilized LAN-5 cells to guanosine 5'-[gamma-thio]triphosphate (GTP[S]), a non-hydrolysable GTP analogue, induced a dose-dependent release of [3H]AA. A non-specific nucleotide effect was excluded, since similar stimulatory effects on AA mobilization were not observed by GTP, ATP, CTP, ADP and GDP. IFN-gamma-stimulated AA release was completely blocked by the guanine nucleotide analogue that inhibits G-protein function, guanosine 5'-[beta-thio]diphosphate (GDP[S]). A role for G-proteins in IFN-gamma-R coupling to PLA2 was further supported by the inhibition of IFN-gamma-induced [3H]AA release by treatment of permeabilized cells with pertussis toxin and with the antiserum against the common alpha-subunits of G-proteins. To determine a possible contribution to AA mobilization by the phospholipase C and diacyglycerol lipase pathway or by protein kinase C activation, the effects of neomycin, a phospholipase C inhibitor, and PMA (phorbol 12-myristate 13-acetate), a direct activator of protein kinase C, were investigated. Neither neomycin nor PMA affected either basal or IFN-gamma-stimulated AA release. Ca2+ concentration, which has been shown to regulate the activity of some PLA2s, does not appear to play an important role in the regulation of the IFN-gamma-stimulated PLA2 activity, since incubating permeabilized cells in different concentrations of Ca2+ induced AA release without affecting the IFN-gamma response. Altogether, these findings suggest the existence of IFN-gamma-R, which couples a Ca(2+)-independent PLA2 activation via pertussis-toxin-sensitive G-proteins.
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PMID:Interferon-gamma-stimulated and GTP-binding-proteins-mediated phospholipase A2 activation in human neuroblasts. 839 12

The effects of TPA (12-0-tetradecanoylphorbol-13-acetate) and G-protein modulators on the concentration of cytoplasmic Ca2+ ([Ca2+]i), cytoplasmic pH and cell growth were investigated in monoblastoid U-937 cells. The G-protein activator NaF causes a dose-dependent increase of [Ca2+]i, that is partially sensitive to inhibition by pertussis toxin. The [Ca2+]i rise appears to come mainly from extracellular sources, and the Ca2+ influx is mediated by channels insensitive to the Ca2+ blocker verapamil. The Ca2+ ionophore ionomycin causes a biphasic rise of [Ca2+]i, reaching steady state levels slightly higher than those attained with NaF. TPA per se has no effect on [Ca2+]i, but potently reverses the NaF or ionomycin induced [Ca2+]i rise. Also, TPA partially counteracted the acidification induced by NaF. Both NaF and ionomycin per se had no effect on cell growth but partially counteracted TPA induced growth inhibition. Interferon-gamma and tumor necrosis factor-alpha did not affect [Ca2+]i by themselves but lowered the [Ca2+]i of NaF stimulated cells. The cytokines had no effect on cytoplasmic pH. This study indicates that elevations of [Ca2+]i in themselves does not trigger proliferation, but alterations of [Ca2+]i modulates the regulation of U937-cell growth.
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PMID:Modulation of calcium signalling and proliferation in monoblastoid U-937 cells. 871 82

Interferon-gamma (IFN-gamma) has multiple effects on Ca2+ signalling in polymorphonuclear neutrophils (PMNs), including evoked cytosolic Ca2+ transients, increased capacitative calcium influx and increased sequestration of Ca2+ in intracellular stores. The present study was conducted to elucidate the mechanism behind the Ca2+ transients. As observed before, the IFN-gamma-evoked Ca2+ signals were apparent when extracellular Ca2+ was removed. A new finding was that the proportion of responding cells and the extent of calcium release increased with increasing time in EGTA buffer. As assessed by N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated Ca2+ release, the intracellular stores were depleted during this incubation period, and the extent of depletion correlated well with the appearance of IFN-gamma-induced Ca2+ signals. This store dependence of the IFN-gamma-induced Ca2+ signals was confirmed by the appearance of IFN-gamma-evoked Ca2+ signals in the presence of extracellular Ca2+ after store depletion by thapsigargin. The appearance of IFN-gamma-mediated Ca2+-signals in the presence of EGTA indicates that IFN-gamma stimulates Ca2+ release from intracellular stores. This was confirmed by the inability of the calcium transportation blocker La3+ to abolish the IFN-gamma response and the total abrogation of the response by the phospholipase C inhibitor U73122. Although these latter results imply a role for inositol 1,4,5-trisphosphate(IP3) in IFN-gamma signalling, comparison of IFN-gamma-evoked responses with fMLP responses revealed clear differences that suggest different signal-transduction pathways. However, responses to fMLP and IFN-gamma were both depressed by pertussis toxin, and the IFN-gamma responses were, in addition, inhibited by the tyrosine kinase inhibitor genistein. Further evidence of the involvement of tyrosine kinase was a slight stimulatory effect of the protein tyrosine phosphatase inhibitor sodium orthovanadate. The PI-3K activity was of minor importance. In conclusion, we present evidence of a novel signal-transduction mechanism for IFN-gamma in PMNs, dependent on tyrosine kinase activity, a pertussis toxin-sensitive G protein and phospholipase C activity.
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PMID:Interferon-gamma elicits a G-protein-dependent Ca2+ signal in human neutrophils after depletion of intracellular Ca2+ stores. 1004 87