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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Helper T (Th) cells can be classified functionally into two main types. Broadly, Th1 cells play a major role in eliminating viral pathogens, while Th2 cells mediate anti-parasite immunity and allergic responses. These functions are thought to depend on characteristic and distinct patterns of cytokine production. Infection with human respiratory syncytial virus, an important common cold virus, causes transient lymphocytic bronchiolitis in mice. Activated T cells are partly responsible for this disease, but also eliminate the virus. To show whether polarized cytokine production occurs in individual cells during viral bronchiolitis, we sampled murine bronchoalveolar lavage and mediastinal lymph node cells before and after infection. RT-PCR of cellular mRNA and flow cytometric analysis of intracellular cytokine production showed a rapid IFN-gamma response at both sites, which persisted for more than 3 weeks in the lung. Most IFN-gamma-producing cells were CD8+. Some early CD4+ IFN-gamma-producing cells also made IL-10. Only low levels of IL-2, IL-4 and IL-5 mRNA or protein expression were detected at any time at either site. No cytokines were detected in B cell populations at either site. These novel techniques show the true complexity of cytokine production patterns on a cell-by-cell basis, allowing T cells to be reclassified according to function.
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PMID:Th1 and Th2 cytokine induction in pulmonary T cells during infection with respiratory syncytial virus. 888 77

Despite similarities in the cellular response to allografts and xenografts, some aspects of the xenogeneic immune response are unique. We find that both freshly isolated and primed human peripheral blood lymphocytes manifest MHC unrestricted cytolysis of porcine cells. While natural antibody-mediated mechanisms account for variable levels of cytotoxicity, reproducible killing in the absence of human serum is attributable to natural killer (NK) cells. This was shown by cold target inhibition with K562 cells, increased antiporcine cytotoxicity after enrichment for CD56+ cells, and significantly reduced lytic activity after depletion of CD56+ cells. Increased anti-porcine cytotoxicity after mixed culture of human and porcine cells was due to differentiation of NK cells to lymphokine-activated killer (LAK) cells and was IL-2 dependent. After depletion of NK cells, T-cell-mediated anti-porcine cytotoxicity could also be demonstrated. We conclude that the human anti-porcine cellular cytotoxic response is due to multiple cell types that include T cells in addition to NK and LAK cells.
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PMID:Human natural killer cells account for non-MHC class I-restricted cytolysis of porcine cells. 902 23

NK cells from F1(AxB) hybrid mice are known to reject bone marrow grafts from either parent A or parent B (hybrid resistance). Using cold target competition in an in vitro hybrid resistance assay, we demonstrate in this work that parent A and parent B are killed by different NK subsets. As confirmation of the existence of these subsets, and to determine whether they undergo a selection/education process during NK cell ontogeny, we constructed bone marrow chimeras in which NK1.1-depleted bone marrow cells from F1 mice were allowed to mature in the microenvironment of either parent A or parent B. These F1-reconstituted chimeras were shown to have normal NK cell numbers and lytic ability in terms of YAC-1 killing and Ab-mediated redirected lysis. Using a three-color flow cytometry analysis in an in vivo hybrid resistance assay, we found that A targets, but not B targets, were less effectively removed by the F1 NK cells that develop in an A recipient (F1-->A chimeras) than in normal F1 or F1-->F1 chimeric mice. IL-2-activated killer cultures of cells from these chimeras, however, did not show a significant difference in the anti-parent killing response in an in vitro assay. These results suggest that NK cells exist in subsets and that self-reactive NK subsets can be rendered unresponsive by radioresistant host element(s). However, this unresponsiveness can be broken when the NK cells are removed from the in vivo environment.
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PMID:Mouse natural killer subsets defined by their target specificity and their ability to be separately rendered unresponsive in vivo. 905 94

Effect of lowering the levels of class I MHC antigens, on the ability of three murine (YAC, P815, SP2O) and three human (Molt4, Raji, HR7) tumor cell lines, to compete in cold target inhibition assays, was studied. Specific reduction in class I MHC levels (range 60-76%) was induced by brief exposure to citrate buffer (pH 3.0). Susceptibility of the acid pH treated tumor cells to lysis by IL-2 activated NK cells, was found to be significantly increased in all cases with the exception of YAC cells. Reduction in class I MHC antigen expression by acid pH treatment, had no significant effect on competing ability of the tumor cells. In contrast, tumor cells on which MHC class I antigens were upregulated by interferon treatment, had significantly lower ability to compete. These results suggest that the mechanisms of altered interactions between MHC I up or down regulated target cells may be different. A model compatible with increased NK susceptibility along with an unaltered ability to compete for acid pH treated tumor cells, has been proposed.
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PMID:Mechanism of interaction of pH 3.0 treated tumor cells expressing lower levels of class I MHC antigens, with IL-2 activated NK cells. 916 83

Ischemia/reperfusion (I/R) injury associated with renal transplantation may influence both early graft function and late changes. The initial (</= 7 d) events of warm and in situ perfused cold ischemia of native kidneys in uninephrectomized rats were examined. mRNA expression of the early adhesion molecule, E-selectin, peaked within 6 h; PMNs infiltrated in parallel. T cells and macrophages entered the injured kidney by 2-5 d; the associated upregulation of MHC class II antigen expression suggested increased immunogenicity of the organ. Th1 products (IL-2, TNFalpha, IFNgamma) and macrophage-associated products (IL-1, IL-6, TGFbeta) remained highly expressed after 2 d. To examine directly the effects of selectins in I/R injury, a soluble P-selectin glycoprotein ligand (sPSGL) was used. Ischemic kidneys were perfused in situ with 5 microg of sPSGL in UW solution; 50 microg was administered intravenously 3 h after reperfusion. E-selectin mRNA remained at baseline, leukocytes did not infiltrate the injured organs throughout the 7-d period, and their associated products were markedly inhibited. Class II expression did not increase. No renal dysfunction secondary to I/R occurred. The early changes of I/R injury may be prevented by treatment with soluble P- and E-selectin ligand. This may reduce subsequent host inflammatory responses after transplantation.
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PMID:The cytokine-adhesion molecule cascade in ischemia/reperfusion injury of the rat kidney. Inhibition by a soluble P-selectin ligand. 916 98

In this study, a relationship between target cell sensitivity to natural killing and target cell expression of the molecular chaperone++ calnexin was assessed. The NK-resistant cell line NKR was originally derived from the NK-sensitive, human T-cell line CEM and does not synthesize calnexin protein or mRNA. The cell lines CEM, NKR and 1B9 (NKR transfected with a calnexin cDNA) were compared in a number of assays. All the lines but CEM were resistant to NK in conventional 4 h cytotoxicity assay, but were highly sensitive to IL-2 activated NK. Incubation of NK cells with CEM but not with the other two lines led to increased expression of the NK cell activation marker CD69. Treatment of effector cells with PGE2 and TGF-beta resulted in an inhibition of NK activity and CD69 expression. The calnexin transfected clone 1B9 clone had intermediate ability to block cytotoxicity in cold target inhibition assay compared to CEM and NKR. Expression of the adhesion molecules CD44 and LFA-1alpha was significantly higher on both calnexin positive cell lines compared to NKR. These data suggest that calnexin controls the expression of some, but not all, target structures that are necessary for binding and activation of NK cells.
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PMID:The role of calnexin in NK-target cell interaction. 956 77

We examined the feasibility of using induced sputum to evaluate the airway inflammatory response to natural acute respiratory virus infections. We recruited eight asthmatics and nine healthy subjects on Day 4 of a cold. Viral infection was confirmed in six of the asthmatics (influenza A or B) and six of the healthy subjects (influenza A, rhinovirus, adenovirus, respiratory syncytial virus, and coronavirus). In the subjects with confirmed virus infection, five of the asthmatics had an objective exacerbation of asthma during the cold. Their sputum on Day 4 showed a high median total cell count of 19.7 x 10(6) cells/ml with a modest neutrophilia (58. 5%) and high levels of interleukin-8 (IL-8) (16,000 pg/ml), eosinophilic cationic protein (ECP) (1,880 microgram/L) and very high levels of fibrinogen (250 mg/L). In contrast, the proportion (1.3%) and absolute number of eosinophils was low. IL-2 levels were within the normal range, whereas IL-5 and interferon gamma were under the limit of detection of the assays. In the healthy subjects with a confirmed virus infection the sputum findings were qualitatively similar but significantly less prominent. Sputum IL-8 on Day 4 was strongly correlated with neutrophils (rs = 0.8, p < 0.001). This correlation was also significant when each group was analyzed separately. On Day 21 there was a fall in the absolute number of neutrophils and in ECP and fibrinogen levels in both groups. Similar results were found in the two asthmatic and three healthy subjects with a cold of comparable severity but in whom viral infection was not confirmed. We conclude that induced sputum examination can be used to study the effects of natural colds and influenza on the airways of the lungs. The results also suggest that natural colds, on Day 4, cause neutrophilic lower airway inflammation that is greater in asthmatics than in healthy subjects. The greater inflammatory response in asthmatics may be due to the changes associated with trivial eosinophilia or to the different viruses involved.
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PMID:Asthma and natural colds. Inflammatory indices in induced sputum: a feasibility study. 976 79

Mitochondrial energetic and oxidative dysfunctions caused by free radical production trigger release of proinflammatory cytokines involved in organ rejection. The aim of this study was to investigate the role of a fluoroquinolone drug, pefloxacin (PFX) and those of various cold preservation solutions on pancreatic beta cell viability. Our data clearly demonstrate that islet cell viability, as determined by glucose-stimulated insulin secretion, is directly correlated with reduced expression of microsomal cytochrome P-450IIIA. Moreover, IL-2, a known mediator of apoptosis was found to be downregulated, whereas TNF-alpha had been upregulated for the first 18 hours after pefloxacin administration. These results demonstrate that pefloxacin downregulates the expression of cytochrome P-450IIIA isozyme and regulates the production of TNF-alpha and IL-2. Thus, we postulate that the presence of pefloxacin in the pancreatic islet cells before organ preservation facilitates increased cell viability.
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PMID:Mitochondrial activity after cold preservation of pancreatic islet cells treated with pefloxacin (PFX). 986 97

1. To delineate the mechanism by which cyclic AMP (cAMP) suppresses interleukin (IL)-5 synthesis, the effects of prostaglandin (PG) E2, forskolin, dibutyryl (db)-cAMP and the Ca2+ ionophore, ionomycin on cytokine synthesis, proliferation and CD25 expression of human T cells were investigated. Further studies were performed by measurement of the intracellular concentrations of cyclic AMP ([cAMP]i) and Ca2+ ([Ca2+]i) and by electrophoretic mobility shift analysis (EMSA). 2. PGE2, forskolin and db-cAMP suppressed IL-5 production by human T cell line following T cell receptor (TCR)-stimulation. PGE2 suppressed TCR-induced messenger RNA (mRNA) expression of IL-2, IL-4 and IL-5, as well as proliferation and CD25 expression. 3. Cyclic AMP-mediated suppression of cytokine synthesis, proliferation and CD25 expression in human T cells were attenuated by ionomycin. 4. [cAMP]i was increased by PGE2 and forskolin. PGE2 suppressed the TCR-induced biphasic increase in [Ca2+]i. EMSA revealed that four specific protein-DNA binding complexes related to NF-AT were detected at the IL-5 promoter sequence located from -119 to -90 relative to the transcription initiation site. The slowest migrating complex induced by TCR stimulation was enhanced by PGE2 and further upregulated by ionomycin. Another binding which did not compete with cold AP-1 oligonucleotides, was constitutively present and was unaffected by PGE2 but enhanced by ionomycin. 5. The suppressive effect of cyclic AMP on human IL-5 synthesis is mediated by interference with intracellular Ca2+ mobilization but distinct from the NF-AT-related pathway.
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PMID:Cyclic AMP suppresses interleukin-5 synthesis by human helper T cells via the downregulation of the calcium mobilization pathway. 1038 54

The effects of a physical stressor, cold water stress (CWS), within the central nervous system were investigated in the acute phase of infection with Toxoplasma gondii. Female BALB/c mice were subjected to CWS for 5 min each day for 8 days prior to oral infection with 20 cysts of the low virulent ME 49 strain. Animals were killed at 10-day intervals to detect inflammation, gliosis, and expression of intracerebral cytokine mRNAs. Zones of inflammation were detected by Nissl staining and gliosis by immunoreactivity to glial fibrillary acidic protein. Larger zones of inflammation and reactive astrogliosis were consistently observed in mice subjected to CWS and infected (CWS +INF) compared to control infected (INF) mice. Expression of interleukin (IL)-1beta, IL-2, IL-12, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and inducible nitric oxide synthase (iNOS) were decreased in CWS+INF mice at 10 days postinoculation (PI), followed by a gradual increase after day 20 PI. This was in contrast to increased expression of these cytokines at 10 days PI in INF mice with a gradual decline thereafter. Inflammation and astrogliosis in CWS+INF mice were associated with an increased expression of IL-1beta, IL-6, IL-12, and TNF-alpha between 20 and 30 days PI. These findings correlated with the continuous gene expression of tachyzoite surface antigen (SAG)-1 mRNA in CWS+INF mice compared to its sharp decline in INF mice after 20 days PI. These results suggest that CWS delays regulation and control of intracerebral Toxoplasma gondii during acute infection in BALB/c mice by decreasing the early expression of IFN-gamma, IL-2, TNF-alpha, iNOS, IL-1beta, and IL-12, while increasing the expression of IL-6, a counterregulatory cytokine.
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PMID:Cold stress-induced modulation of inflammatory responses and intracerebral cytokine mRNA expression in acute murine toxoplasmosis. 1057 24


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