RESUMO
BACKGROUND: IL-18 was originally cloned as a IFN-gamma inducing factor in primed T cells. In synergy with IL-12, IL-18 has been shown to induce strikingly high levels of IFN-gamma production by T cells and to enhance Th1 development. Also this cytokine exerts induction of Th2 development through IL-4 induction. METHODS: Resting CD4+ T cells were sorted by negative selection and activated by anti-CD3 plus anti-CD28 Ab. Expression of IL-12 binding sites, IL-18 binding sites, IL-18Ralpha, and GATA-3 mRNA were analysed by FACS and RT-PCR, respectively. RESULTS: Resting CD4+ T cells expressed IL-18Ralpha chain but not IL-18 binding sites, suggesting a lack of IL-18Rbeta expression. IL-18Ralpha was maintained on the Th1 and Th2 committed cells. IL-18 binding sites were induced on the Th1 but not Th2 cells. Exposure of these cells to IL-18 led to up-regulation of GATA-3 mRNA expression only in Th2 committed cells. To elucidate the relationship between IL-18Ralpha expression and GATA-3 induction by IL-18, Th1 and Th2 committed cells were further cultured in medium with or without IL-12 for 2 days. IL-12 binding sites were maintained on the Th1 and Th2 cells regardless of IL-12 treatment, but IL-18Ralpha expression was rapidly down-regulated on the IL- 12-untreated Th2 cells which did not induce GATA-3 mRNA expression followed by IL-18 stimulation. CONCLUSION: IL-12 supports expression of IL-18Ralpha and GATA-3 mRNA expression was induced by IL-18 through IL-18Ralpha without expression of IL-18 binding site in Th2 cells.
Assuntos
Sítios de Ligação , Células Clonais , Interleucina-12 , Interleucina-18 , Interleucina-4 , RNA Mensageiro , Linfócitos T , Células Th2 , Regulação para CimaRESUMO
BACKGROUND: Disseminated intravascular coagulation (DIC) is a clinicopathologic syndrome for widespread intravascular coagulation. DIC occurs when the processes that regulate coagulation break down. Staphylococcal infection is one of the causes of DIC. Staphylococcus aureus produces coagulase that can clot plasma. There are two different tests to detect the coagulase; a tube test for free coagulase and a slide test for bound coagulase or clumping factor. The goal of the present study is to evaluate the characteristics of coagulase in Staphylococcus aureus for establishment of an in-vitro model for DIC. METHODS: Coagulase tests were performed by mixing plasma with two-fold diluted culture broths, culture supernatant and culture filtrates. Coagulase activity was expressed as the reciprocal of the highest dilution titer. Cell pellets treated with normal saline, ethyl alcohol, and aceton were used for the clumping tests. Platelet aggregation tests were conducted using a culture broth and a concentrated culture supernatant. A fibrinogen binding protein was isolated from sonificated bacteria and thus, determined the molecular weight. RESULTS: Coagulase activity was higher in the broth culture than in the culture supernatant and culture filtrate. Coagulase activity decreased after incubation at 37degrees C for 24 hours but culture filtrates were clumped after boiling at 100degrees C for 10 minutes. Alcohol and aceton did not inhibit the clumping test. S. aureus induced platelet aggregation but a concentrated culture filtrate did not induce platelet aggregation. Molecular weight of fibrinogen binding protein was 57 kDa. CONCLUSIONS: It is suggested that the plasma clot was due to free coagulase or a clumping factor. Free coagulase is different from a clumping factor. We concluded that the pathogenesis of DIC in the staphylococcal infection was due to platelet aggregation triggered by a clumping factor or coagulase with other substances.
Assuntos
Bactérias , Proteínas de Transporte , Coagulase , Dacarbazina , Coagulação Intravascular Disseminada , Etanol , Fibrinogênio , Peso Molecular , Plasma , Agregação Plaquetária , Infecções Estafilocócicas , Staphylococcus aureus , StaphylococcusRESUMO
In order to explore the potential of ascorbic acid supplementation for the prevention and treatment of herpes simplex viral diseases, plaque reduction assays were performed. Ascorbic acid as well as copper chloride/ferric chloride were added to wells containing Vero cells infected with herpes simplex virus type 1 (HSV-1), and the infectivity of HSV-1 was determined. Since copper and iron are major transition metals in human plasma, near the normal human plasma concentrations of them were used for experiments. When Cu(II) and Fe(III) were applied, there were no significant differences between virus control and Cu(II)/Fe(III)-treated groups. But, when appropriate concentrations of ascorbic acid were added to wells, meaningful differences between control and ascorbate-treated groups were found. In the presence of Cu(II)/Fe(III) at 5.8/3.7 muM, 72-h treatment with ascorbate at 50 muM reduced HSV-1 infections to 10.77%+/-4.25% (P 0.05). Current recommended dietary allowance (RDA) of ascorbic acid is 60 mg/day, and the oral intake of 60 mg/day of ascorbic acid yields plasma ascorbic acid at 45 to 58 muM in a healthy adult man. Therefore, the results of this study suggest that the maintenance of appropriate level (more than 50 muM) of ascorbic acid in human plasma by appropriate amount (more than the RDA) of ascorbic acid supplementation may be helpful for the prevention and treatment of diseases caused by HSV-1 in an adult man. In addition, this study also suggests that ascorbic acid may be useful for the prophylaxis of fatal HSV-1 infections in neonates and the prevention of HSV-1 reactivation in immunocompromised hosts.
Assuntos
Adulto , Humanos , Recém-Nascido , Ácido Ascórbico , Cobre , Herpes Simples , Herpesvirus Humano 1 , Hospedeiro Imunocomprometido , Ferro , Metais , Plasma , Recomendações Nutricionais , Simplexvirus , Células Vero , VirosesRESUMO
No abstract available.
Assuntos
Animais , Camundongos , Células Clonais , Clonagem de Organismos , MastócitosRESUMO
The mast cell is an essential effector cell in allergic inflammation through its capacity to respond to IgE dependent activation. Mast cells also participate in the modulation of physiologic processes, but the role of mast cell in these processes is still unclear. Recently, the number of structurally defined chernoattractants for leukocytes has greatly increased, owing to largely to the identification of the chemokine superfamily. In this study we examined the pattern of expression of chemokines and their receptors in HMC-1 after treatment with PMA/A23187 and/or LPS using RT-PCR and ELISA. Messenger RNA of IL-8, the representative CXC chemokine, was induced after PMA/ A23187 treatment. All of the CC chemokines tested, except eotaxin, were induced after PMA/A23187 treatment. CCR1, CXCR2, CXCR3 and CXCR4 were expressed in all test groups regardless of activation. CCR3 was expressed only at 3 hours of activation. CCR2, CCR5 and CXCR1 were not expressed in mast cell line. Production of most of chemokine proteins was not detected in resting state and increased significantly after 3 hours of activation with PMA/A23187. The effect of LPS treatment was negligible. MCP-1 protein was always produced without activation and accurnulated in a time-dependent rnanner. These data suggest that the expression of mRNA and protein of chemokines and chemokine receptors are regulated transcriptionally and translationally. Human mast cell may respond to various stimuli by producing chemokines and their receptors to regulate their function and may act autonomously or through other inflammatory cell that they recruited.
Assuntos
Humanos , Calcimicina , Quimiocinas , Quimiocinas CC , Ensaio de Imunoadsorção Enzimática , Imunoglobulina E , Inflamação , Interleucina-8 , Leucócitos , Mastócitos , Reação em Cadeia da Polimerase , Receptores de Quimiocinas , RNA MensageiroRESUMO
The mast cell is an essential effector cell in allergic inflammation through its capacity to respond to IgE dependent activation. Mast cells also participate in the modulation of physiologic processes, but the role of mast cell in these processes is still unclear. Recently, the number of structurally defined chernoattractants for leukocytes has greatly increased, owing to largely to the identification of the chemokine superfamily. In this study we examined the pattern of expression of chemokines and their receptors in HMC-1 after treatment with PMA/A23187 and/or LPS using RT-PCR and ELISA. Messenger RNA of IL-8, the representative CXC chemokine, was induced after PMA/ A23187 treatment. All of the CC chemokines tested, except eotaxin, were induced after PMA/A23187 treatment. CCR1, CXCR2, CXCR3 and CXCR4 were expressed in all test groups regardless of activation. CCR3 was expressed only at 3 hours of activation. CCR2, CCR5 and CXCR1 were not expressed in mast cell line. Production of most of chemokine proteins was not detected in resting state and increased significantly after 3 hours of activation with PMA/A23187. The effect of LPS treatment was negligible. MCP-1 protein was always produced without activation and accurnulated in a time-dependent rnanner. These data suggest that the expression of mRNA and protein of chemokines and chemokine receptors are regulated transcriptionally and translationally. Human mast cell may respond to various stimuli by producing chemokines and their receptors to regulate their function and may act autonomously or through other inflammatory cell that they recruited.
Assuntos
Humanos , Calcimicina , Quimiocinas , Quimiocinas CC , Ensaio de Imunoadsorção Enzimática , Imunoglobulina E , Inflamação , Interleucina-8 , Leucócitos , Mastócitos , Receptores de Quimiocinas , RNA MensageiroRESUMO
No abstract available.
